Evaluation of Serum Biochemical Parameters and Metabolism in Smokers: A Case Control Study

Evaluation of Serum Biochemical Parameters and Metabolism in Smokers: A Case Control Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research article Evaluation of Serum Biochemical Parameters and Metabolism in Smokers: A Case Control Study Yılmaz Sezgin This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-982021/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Smoking tobacco is a substantial risk factor for chronic obstructive pulmonary disease and cardiovascular diseases. For this reason, studies on smoking are mostly focused on the pulmonary and cardiovascular systems. Recently, an increase has been observed in the number of studies investigating the relationship between obesity and diabetes and smoking. We investigated the effects of smoking on other serum biochemical parameters and metabolism. Methods This is a case-control study. The case and control groups were formed by clinical randomization by using the data obtained from the hospital information system and patient records, including age, gender, height, and weight. Smokers were identified as the case group, while non-smokers were identified as the control group. In the comparisons of rates Chi-square tests were used and in the comparisons of averages, independent sample t and MANCOVA tests were used. Results When covariance factors such as age, gender, body mass index, and alcohol use were taken into consideration, It found that AST, ALT, and GGT were higher in smokers, whereas vitamin D, vitamin B12, and TSH were higher in non-smokers. Conclusions We found that smoking has a negative effect on liver and bile functions, and vitamin D values ​​are affected secondary to this negative effect. Smoking tobacco Biochemical parameters metabolism Background More than 5,000 chemical compounds have been identified in tobacco and tobacco smoke [ 1 ]. The most well-known of these substances is nicotine and identified with cigarettes. Nicotine is responsible for the addictive effect of smoking [ 2 ]. Smoking is one of the most important risk factors for chronic obstructive pulmonary disease [ 3 , 4 ]. Smoking is accepted to increase the risk of cardiovascular diseases [ 5 , 6 ]. Studies investigating the effects of smoking are mostly focused on the pulmonary and cardiovascular system. The number of studies on the effects of smoking on other systems such as the gastrointestinal system and urinary system than the pulmonary and cardiovascular system is not sufficient to establish a consensus on the effects of cigaret on these systems. Recently, the number of studies investigating the relationship between smoking and obesity and diabetes has been observed to be increased [ 7 , 8 ]. We investigated the effects of smoking on several serum biochemical parameters and metabolism. Methods Study Design This was designed to be a case-control study. Population selection The case and control groups were formed by clinical randomization by using the data obtained from the hospital information system and patient records, including age, gender, height and weight. The case group included 30 individuals with smoking habit and a control group consisted of non-smokers, matching with the case group in terms of number, gender, age and body mass index (BMI). Patients with any known disease and those using medications were not included in the study. Laboratory data of individuals who met the inclusion criteria among patients who admitted to the family medicine outpatient clinic during the last three-months were evaluated for analysis. Laboratory testing The blood samples of the participants were collected at the time of admission. A total of 19 parameters, including creatinine, urea, AST, ALT, GGT, sodium, potassium, albumin, cholesterol, triglyceride, HDL-C, LDL-C, HbA1C, glucose, insulin, vitamin D, vitamin B12, TSH, and free T4 were measured simultaneously for the analysis. Statistical analysis All statistical analyzes were performed by using IBM SPSS software (V25). A value of P <.05 was considered statistically significant. Categorical data were expressed by numbers and percentages. In the comparison of categorical variables chi-square test was used. Numerical data were expressed by mean values. In the comparison of the means independent sample t and MANCOVA tests were used. The compliance of the variances with normal distribution was tested by using box's and levene's tests. Results There was no difference between the case and control groups in terms of gender and BMI. However, the rate of alcohol use was lower in the case group compared to the control group. The mean age was higher in the case group compared to the control group (Table 1 ). Table 1 Comparison of the age, BMI, gender and using alcohol in between case and control groups Characteristics of participants. Case (n=30) Control (n=30) Age: Mean (SD)* 25.80 (3.84) 22.30 (5.54) BMI: Mean (SD) 23.21 (2.73) 22.66 (2.69) Gender: n (%) Female 15 (25) 15 (25) Male 15 (25) 15 (25) Alcohol: n (%)* Yes 7 (11.7) 14 (23.3) No 23 (38.3) 16 (26.7) SD: Standard Deviation; *The statistical significant different was accepted as P < .05 level (2-tailed) According to independent sample t test analysis between smokers and non-smokers; were found significant differences in terms of serum AST, ALT, GGT, LDL-C, vitamin D, vitamin B12 and TSH levels. We found that AST, ALT GGT, and LDL-C levels were higher in the case group, whereas vitamin D, vitamin B12 and TSH levels were higher in the control group (Table 2 ). Table 2 Comparison of the serum biochemical parameters in between case and control groups Case (n=30) Control (n=30) t P value Mean (SD) Creatinine (mg/dL) 0.71 (0.27) 0.69 (0.26) 0.15 .881 Urea (mg/dL) 27.63 (8.35) 24.20 (5.30) 1.90 .062 AST (U/L) 25.90 (10.84) 17.70 (5.42) 3.70 .001* ALT (U/L) 22.50 (10.01) 15.30 (6.04) 3.37 .001* GGT (U/L) 19.80 (7.07) 15.06 (5.31) 2.92 .005* Sodium (mmol/L) 140.60 (3.94) 140.23 (2.69) 0.42 .676 Potassium (mmol/L) 4.18 (0.29) 4.22 (0.38) -0.41 .684 Albumin (g/L) 4.38 (0.35) 4.34 (0.22) 0.40 .688 Cholesterol (mg/dL) 157.50 (24.03) 155.46 (23.09) 0.33 .740 Triglycerides (mg/dL) 84.10 (26.37) 73.16 (34.15) 1.38 .171 HDL-C (mg/dL) 55.66 (12.48) 53.26 (10.92) 0.79 .431 LDL-C (mg/dL) 90.43 (18.33) 78.96 (21.70) 2.21 .031* HbA1C (%) 5.17 (0.41) 5.29 (0.21) -1.41 .163 Glucose (mg/dL) 87.20 (6.89) 84.96 (8.60) 1.10 .272 Insulin (µU/mL) 9.09 (5.98) 7.95 (7.39) 0.65 .512 Vitamin D (ng/mL) 14.50 (3.34) 18.76 (9.01) -2.42 .019* Vitamin B12 (ng/L) 110.30 (52.03) 167.66 (78.85) -3.32 .002* TSH (mIU/L) 1.27 (0.47) 1.93 (0.86) -3.62 .001* Free T4 (ng/dL) 0.81 (0.15) 0.82 (0.14) -0.16 .869 HOMA-IR 1.97 (1.34) 1.75 (2.04) 0.47 .635 SD: Standard Deviation; *İndependent simple t test is significant at the P < .05 level (2-tailed). According to one-way MANCOVA analysis performed by taking into consideration covariance factors including age, gender, BMI and alcohol use between smokers and non-smokers were found significant differences in terms of serum biochemical parameters. The assumption of variance equality could not be met, since the value of P obtained from the box's test result was less than .05 (P = .001). In this case, pillai's trace results were taken into account for MANCOVA test statistics (pillai's trace = 0.57, F[20, 35] = 2.36, P = .013). When the covariance factors were considered, we found that the difference between the two groups continued for AST, ALT, GGT, vitamin D, vitamin B12, and TSH, whereas the difference did not continued for LDL-C (Table 3 ). Table 3 Comparison of serum biochemical parameters between case and control groups, taking into account covariate factors Case (n=30) Control (n=30) Levene's F P value Mean a (SE) Creatinine (mg/dL) 0.69 (0.04) 0.71 (0.04) 0.901 0.13 .713 Urea (mg/dL) 27.46 (1.23) 24.37 (1.23) 0.001 2,85 .097 AST (U/L) 25.97 (1.65) 17.62 (1.65) 0.040 11.67 .001* ALT (U/L) 22.73 (1.59) 15.06 (1.59) 0.002 10.63 .002* GGT (U/L) 19.51 (1.08) 15.34 (1.08) 0.532 6.72 .012* Sodium (mmol/L) 140.68 (0.60) 140.15 (0.60) 0.085 0.34 .558 Potassium (mmol/L) 4.20 (0.06) 4.19 (0.06) 0.053 0.01 .916 Albumin (g/L) 4.38 (0.05) 4.34 (0.05) 0.392 0.22 .641 Cholesterol (mg/dL) 156.99 (4.54) 155.97 (4.54) 0.842 0.02 .880 Triglycerides (mg/dL) 83.98 (5.85) 73.28 (5.85) 0.134 1.52 .222 HDL-C (mg/dL) 55.48 (0.05) 53.45 (0.05) 0.803 0.36 .547 LDL-C (mg/dL) 89.44 (3.90) 79.95 (3.90) 0.463 2.70 .106 HbA1C (%) 5.17 (0.05) 5.30 (0.05) 0.024 2.43 .124 Glucose (mg/dL) 87.37 (1.53) 84.78 (1.53) 0.147 1.30 .259 Insulin (µU/mL) 9.38 (1.29) 7.66 (1.29) 0.843 0.80 .373 Vitamin D (ng/mL) 14.74 (1.23) 18.52 (1.23) 0.070 4.29 .043* Vitamin B12 (ng/L) 105.80 (12.37) 172.16 (12.37) 0.045 13.18 .001* TSH (mIU/L) 1.30 (1.12) 1.89 (1.12) 0.006 10.91 .002* Free T4 (ng/dL) 0.80 (0.02) 0.82 (0.02) 0.777 0.23 .629 HOMA-IR 2.03 (0.33) 1.69 (0.33) 0.853 0.46 .496 SE: Standard Error; *One-way MANCOVA is significant at the P < .05 level (2-tailed). a: Covariates appearing in the model are evaluated at the following values; age = 24.05, BMI = 22.94, gender = 1.50, alcohol = 1.35 There was no significant difference between the case group and the control group in terms of glycemic parameters. However, HOMA-IR values were higher in the case group while HbA1C values were higher in the control group (Table 3 ). Discussion The fact that the alcohol use rate was lower and the average age was higher in the case group in comparison to the control group, indicates that randomization was not performed very well. However, this limitation has been minimized by one-way MANCOVA analyzes performed by considering covariance factors such as age, gender, BMI and alcohol use. In our study, the higher values of serum AST, ALT, and GGT ​​observed in the case group indicates that smoking affects liver and bile functions, negatively. In the literature there are studies that support our results. In a study conducted on males, GGT was higher in smokers in comparison to non-smokers [ 9 ]. It has also been suggested that smoking causes cellular damage by causing oxidative stress and ultrastructural changes on hepatocytes [ 10 ]. In our study, the lower serum vitamin D values ​​in the case group compared to the control group may be caused by a defect in the vitamin D synthesis in the liver and / or an absorption disorder. Cholecalciferol synthesized in the epidermis or taken with diet turns into 25-hydroxycholecalcidiol in the liver and then to 1,25-hydroxycholecalcitriol as the active form in the kidney [ 11 ]. The 25-hydroxycholecalcididol transformation that takes place in the liver may be impaired due to the negative effects of smoking on hepatocytes. In addition, absorption of Vitamin D, a fat-soluble molecule, may be impaired due to the negative effects of smoking on the biliary system. In the literature, there are a few studies supporting our results, related to vitamin D in our study. However, the reasons for vitamin D deficiency in smokers have not been fully clarified in these studies [ 12 ]. We found that, serum vitamin B12 values ​​were lower in the case group compared to the control group. These our results are in line with the knowledge in the literature. There are studies suggesting that smoking, which is a source of free radicals, causes serum vitamin B12 levels to decrease [ 13 – 15 ]. The use of tobacco causes the serum cyanide level to increase due to the cyanide it contains. It has been shown that high cyanide levels increase the excretion of thiocyanate from the kidneys, which is associated with a decrease in serum vitamin B12 level [ 16 ]. We found that serum TSH levels were lower in the case group compared to the control group. In the literature, it has been reported that the effects of smoking on thyroid tissue are complex, while smoking generally increases susceptibility to hypertroidism [ 17 , 18 ]. This relationship between smoking and thyroid functions may be due to vitamin B12 deficiency seen in smokers. Although there is a widespread opinion in the literature that vitamin B12 deficiency and increased levels of homocysteine ​​increase susceptibility to hypothyroidism and autoimmune thyroid diseases, studies on animals suggest contradictory evidence [ 19 – 21 ]. In addition, S adenosyl methionine, a product of the homocysteine ​​methionine cycle with additive vitamin B12 cofactor stimulates TRH and therefore TSH release and TSH receptor interaction [ 22 ]. In our study, we found no difference in kidney function, between smokers and non-smokers. In the literature, it has been reported that kidney functions are affected by smoking due to the increase in nicotine-induced adrenergic activity [ 23 ]. In our study, no significant difference was found between smokers and non-smokers in terms of serum glycemic index and lipid profile. However, HOMA-IR values were higher in the case group while HbA1C values were higher in the control group. HOMA-IR values show the momentary state, while HbA1C shows the last three-month period. These findings indicate that there was a predisposition to hypoglycaemia in the smoker group in the past. In a study conducted on obese people, HOMA-IR was found to be higher in smokers compared to non-smokers, but there was no significant difference in serum glucose, insulin, total cholesterol, triglyceride, HDL-C, and LDL-C levels [ 24 ]. Nicotine causes hyperglycemia by increasing gluconeogenesis by stimulating catecholamine-mediated glucagon release from the adrenergic medulla [ 8 ]. It is plausible that the relationship between smoking and insulin resistance, which is frequently emphasized in the literature, may be a result rather than a cause. Given the assumption that hyperinsullinemia-induced hypoglycaemia episodes seen at the onset of type 2 diabetes can be prevented by increasing gluconeogenesis, nicotine may be preferred due to an avoidance behavior. Conclusions As a result, we suggest that smoking has a negative effect on liver and bile functions, and vitamin D values ​​are affected secondary to this negative effect. In addition, the relationship between smoking and thyroid functions may be due to vitamin B12 deficiency seen in smokers. Abbreviations BMI Bbody mass index AST Aspartate aminotransferase ALT Alanine aminotransferase GGT Gamma-glutamyl transferase HDL-C High-density lipoprotein cholesterol LDL-C Low-density lipoprotein cholesterol TSH Thyroid stimulating hormone HbA1C Glycosylated hemoglobin HOMA-IR Homeostatic model assessment for insulin resistance TRH Thyrotropin releasing hormone Declarations Acknowledgments None Authors' contributions The concept and design of the study: Y.S. and S.B.; Data acquisition: Y.S., S.B. and A.P.; Statistical analysis: Y. S.; Analyzed the data and drafted the manuscript: Y.S., S.B. and A.P. All authors read and approved the final version of the manuscript Funding There is no funding Availability of data and materials The dataset is available from the corresponding author on reasonable request. Ethical approval The study was approved by the Istanbul Training Research Hospital Clinical Research Ethics Committee (Decision no: 2153). Informed consent was not obtained because of retrospective study. Consent for publication Not applicable. Conflicts of Interest The authors declare that no conflicts of interest. References Talhout R, Schulz T, Florek E, Benthem JV, Wester P, Opperhuizen A. Hazardous compounds in tobacco smoke. Int J Environ Res Public Health. 2011;8:613–28. Benowitz NL, Henningfield JE. Reducing the nicotine content to make cigarettes less addictive. Tob Control. 2013;22:14–7. Salvi S. Tobacco smoking and environmental risk factors for chronic obstructive pulmonary disease. Clin Chest Med. 2014;35(1):17–27. Laniado-Laborín R. Smoking and chronic obstructive pulmonary disease (COPD). Parallel epidemics of the 21st century. Int J Environ Res Public Health. 2009;6:209–24. Banks E, Joshy G, Korda RJ, Stavreski B, Soga K, Egger S. etal.Tobacco smoking and risk of 36 cardiovascular disease subtypes: fatal and non-fatal outcomes in a large prospective Australian study. BMC Med. 2019;17(1):128. Messner B, Bernhard D. Smoking and cardiovascular disease: mechanisms of endothelial dysfunction and early atherogenesis. Arterioscler Thromb Vasc Biol. 2014;34(3):509–15. Lee H, Joe KH, Kim W, Park J, Lee DH, Sung KW. etal.Increased leptin and decreased ghrelin level after smoking cessation. Neurosci Lett. 2006;409(1):47–51. Fagard RH, Nilsson PM. Smoking and diabetes-The double health hazard! Primary care diabetes. 2009;3:205–09. Lee D, Kang HW, Kim II. Association between cigarette smoking and serum gamma glutamyl transferase level. Int J Respir Pulm Med. 2019;6:125. Y. Battah KA, Badran DH, Shraideh ZA. Effect of cigarette smoking on the structure of hepatocytes: TEM study. Int J Morphol. 2016;34(4):1239–44. Heath KM, Elovic EP. Vitamin D deficiency: Implications in the rehabilitation setting. Am J Phys Med Rehabil. 2006;85:916–23. Brot C, Jorgensen NR, Sorensen OH. The influence of smoking on vitamin D status and calcium metabolism. Eur J Clin Nutr. 1999;53(12):920–6. Pivathilake HJ, Macaluso M, Hine RJ, Richards EW, Krumdieck CL. Local and systemic effects of cigarette smoking on folate and vitamin B12. Am J Clin Nutr. 1994;60:559–66. Mcgarry JM, Andrews J. Smoking in pregnancy and vitamin B12 metabolism. BMJ. 1972;2:74–7. Sezgin Y. Approach to Vitamin B12 Deficiency. Konuralp Medical J. 2019;11(3):482–8. Linnell JC, Smith AD, Smith CL, Wilson J, Matthews DM. Effects of smoking on metabolism and excretion of vitamin B12. BMJ. 1968;2:215–6. Gülcü F, Polat SA, Gürsü MF. Aşırı sigara kullanımının tiroid fonksiyon testleri ile eser element düzeylerine etkileri. Turkiye Klinikleri J Med Sci. 2003;23(5):386–91. Kim BH, Kim WB, Kim TY, Kim HK, Jeon SH, Lee CW. etal.Association between Cigarette Smoking and Thyroid Function in Adults without Previous History of Thyroid Disease. Endocrinol Metab. 2008;23(2):123–8. Collins AB, Pawlak R. Prevalence of vitamin B12 deficiency among patients with thyroid dysfunction. Asia Pac J Clin Nutr. 2016;25(2):221–6. Atabek ME, Pirgon O, Erkul I. Plasma homocysteine concentrations in adolescents with subclinical hypothyroidism. J Pediatr Endocrinol Metab. 2003;16(9):1245–8. Jacobs RL, Stead LM, Brosnan ME. etal.Plasma homocysteine is decreased in the hypothyroid rat. Can J Physiol Pharmacol. 2000;78(7):565–70. Prasad C, Mori M, Greeley GH Jr, Edwards RM, Wilber JF, Pegues J. Biochemical transmethylation of lipids and neuropeptidergic stimulation of pituitary hormone secretion. Brain Res. 1985;334(1):41–6. Cooper RG. Effect of tobacco smoking on renal function. Indian J Med Res. 2006;124(3):261–8. Yağbasan Y, Ersoy C, Çubukçu E, Ölmez ÖF, İmamoğlu Ş. Morbid obez kadınlarda sigara içiminin obezite indeksleri, insülin direnci, kan basıncı, glisemi ve lipid parametreleri üzerine etkilerinin retrospektif olarak değerlendirilmesi. İnönü Üniversitesi Tıp. Fakültesi Dergisi. 2008;15(4):245–8. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-982021","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":56986368,"identity":"cb0706b5-220e-4130-887a-1c9001c8c8ee","order_by":0,"name":"Yılmaz Sezgin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3UlEQVRIiWNgGAWjYDCCAxCKh4G9AUgZWJCihQfEMpAgXgsDg0QCmCSsg+/2GeMPH/7UyphLPr+64UeBBAN/e3cCXi2S53LMJGfwHOexnJ1TdrMH6DCJM2c34NVicIbHjJlH4hiPwe2ctBs8QC0GErkEtRh//mMA1HLzTNrNP0RqMZBmSKjhMbjBfuw2UbZInmErk+w5cIDH4EwO220ZAwkegn7hO8O8+cOPP3X2BsePP7v55o+NHH97L34tDAwcBkDiMBDzgBjAOCUM2B8AiToYYxSMglEwCkYBJgAAvJ5JE5zUvvAAAAAASUVORK5CYII=","orcid":"","institution":"","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Yılmaz","middleName":"","lastName":"Sezgin","suffix":""}],"badges":[],"createdAt":"2021-10-16 10:13:42","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-982021/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-982021/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":18034302,"identity":"376a322c-b1c7-4ae1-97ed-94b919255300","added_by":"auto","created_at":"2022-02-08 15:41:09","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":260001,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-982021/v1/ab091134-0633-4fd8-9fc3-8636e5d31745.pdf"}],"financialInterests":"","formattedTitle":"Evaluation of Serum Biochemical Parameters and Metabolism in Smokers: A Case Control Study","fulltext":[{"header":"Background","content":"\u003cp\u003eMore than 5,000 chemical compounds have been identified in tobacco and tobacco smoke [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The most well-known of these substances is nicotine and identified with cigarettes. Nicotine is responsible for the addictive effect of smoking [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Smoking is one of the most important risk factors for chronic obstructive pulmonary disease [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Smoking is accepted to increase the risk of cardiovascular diseases [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eStudies investigating the effects of smoking are mostly focused on the pulmonary and cardiovascular system. The number of studies on the effects of smoking on other systems such as the gastrointestinal system and urinary system than the pulmonary and cardiovascular system is not sufficient to establish a consensus on the effects of cigaret on these systems. Recently, the number of studies investigating the relationship between smoking and obesity and diabetes has been observed to be increased [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. We investigated the effects of smoking on several serum biochemical parameters and metabolism.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy Design\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis was designed to be a case-control study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePopulation selection\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe case and control groups were formed by clinical randomization by using the data obtained from the hospital information system and patient records, including age, gender, height and weight. The case group included 30 individuals with smoking habit and a control group consisted of non-smokers, matching with the case group in terms of number, gender, age and body mass index (BMI). Patients with any known disease and those using medications were not included in the study. Laboratory data of individuals who met the inclusion criteria among patients who admitted to the family medicine outpatient clinic during the last three-months were evaluated for analysis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLaboratory testing\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe blood samples of the participants were collected at the time of admission. A total of 19 parameters, including creatinine, urea, AST, ALT, GGT, sodium, potassium, albumin, cholesterol, triglyceride, HDL-C, LDL-C, HbA1C, glucose, insulin, vitamin D, vitamin B12, TSH, and \u0026nbsp;free T4 were measured simultaneously for the analysis. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll statistical analyzes were performed by using IBM SPSS software (V25). A value of P \u0026lt;.05 was considered statistically significant. Categorical data were expressed by numbers and percentages. In the comparison of categorical variables chi-square test was used. Numerical data were expressed by mean values. In the comparison of the means independent sample t and MANCOVA tests were used. The compliance of the variances with normal distribution was tested by using box\u0026apos;s and levene\u0026apos;s tests.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThere was no difference between the case and control groups in terms of gender and BMI. However, the rate of alcohol use was lower in the case group compared to the control group. The mean age was higher in the case group compared to the control group (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of the age, BMI, gender and using alcohol in between case and control groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eCharacteristics of participants.\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCase (n=30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eControl (n=30)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eAge: Mean (SD)*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.80 (3.84)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.30 (5.54)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eBMI: Mean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.21 (2.73)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.66 (2.69)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGender: n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15 (25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15 (25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15 (25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15 (25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAlcohol: n (%)*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (11.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14 (23.3)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23 (38.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16 (26.7)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eSD: Standard Deviation; *The statistical significant different was accepted as \u003cem\u003eP \u0026lt;\u003c/em\u003e .05 level (2-tailed)\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAccording to independent sample t test analysis between smokers and non-smokers; were found significant differences in terms of serum AST, ALT, GGT, LDL-C, vitamin D, vitamin B12 and TSH levels. We found that AST, ALT GGT, and LDL-C levels were higher in the case group, whereas vitamin D, vitamin B12 and TSH levels were higher in the control group (Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of the serum biochemical parameters in between case and control groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCase (n=30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eControl (n=30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003et\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCreatinine (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.71 (0.27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.69 (0.26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.881\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUrea (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e27.63 (8.35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24.20 (5.30)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.062\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAST (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.90 (10.84)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17.70 (5.42)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eALT (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22.50 (10.01)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15.30 (6.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGGT (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19.80 (7.07)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15.06 (5.31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.005*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSodium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e140.60 (3.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e140.23 (2.69)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.676\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePotassium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.18 (0.29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.22 (0.38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.684\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlbumin (g/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.38 (0.35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.34 (0.22)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.688\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCholesterol (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e157.50 (24.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e155.46 (23.09)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.740\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTriglycerides (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e84.10 (26.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e73.16 (34.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.171\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHDL-C (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e55.66 (12.48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e53.26 (10.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.431\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLDL-C (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e90.43 (18.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e78.96 (21.70)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.031*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHbA1C (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5.17 (0.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5.29 (0.21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-1.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.163\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGlucose (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e87.20 (6.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e84.96 (8.60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.272\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInsulin (\u0026micro;U/mL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.09 (5.98)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7.95 (7.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.512\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin D (ng/mL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e14.50 (3.34)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18.76 (9.01)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.019*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin B12 (ng/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e110.30 (52.03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e167.66 (78.85)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-3.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.002*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTSH (mIU/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.27 (0.47)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.93 (0.86)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-3.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFree T4 (ng/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.81 (0.15)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.82 (0.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.869\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHOMA-IR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.97 (1.34)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.75 (2.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e.635\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eSD: Standard Deviation; *İndependent simple t test is significant at the \u003cem\u003eP \u0026lt;\u003c/em\u003e .05 level (2-tailed).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAccording to one-way MANCOVA analysis performed by taking into consideration covariance factors including age, gender, BMI and alcohol use between smokers and non-smokers were found significant differences in terms of serum biochemical parameters. The assumption of variance equality could not be met, since the value of P obtained from the box's test result was less than .05 (P = .001). In this case, pillai's trace results were taken into account for MANCOVA test statistics (pillai's trace = 0.57, F[20, 35] = 2.36, P = .013). When the covariance factors were considered, we found that the difference between the two groups continued for AST, ALT, GGT, vitamin D, vitamin B12, and TSH, whereas the difference did not continued for LDL-C (Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of serum biochemical parameters between case and control groups, taking into account covariate factors\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCase (n=30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eControl (n=30)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eLevene's\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eF\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eMean\u003csup\u003ea\u003c/sup\u003e (SE)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCreatinine (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.69 (0.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.71 (0.04)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.901\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.713\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUrea (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e27.46 (1.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24.37 (1.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2,85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.097\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAST (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.97 (1.65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17.62 (1.65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.040\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eALT (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22.73 (1.59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15.06 (1.59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.002*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGGT (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e19.51 (1.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15.34 (1.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.532\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.012*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSodium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e140.68 (0.60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e140.15 (0.60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.085\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.558\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePotassium (mmol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.20 (0.06)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.19 (0.06)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.053\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.916\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlbumin (g/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.38 (0.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.34 (0.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.392\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.641\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCholesterol (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e156.99 (4.54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e155.97 (4.54)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.842\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.880\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTriglycerides (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e83.98 (5.85)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e73.28 (5.85)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.134\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.222\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHDL-C (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e55.48 (0.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e53.45 (0.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.803\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.547\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLDL-C (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e89.44 (3.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e79.95 (3.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.463\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.106\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHbA1C (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5.17 (0.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e5.30 (0.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.024\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.124\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGlucose (mg/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e87.37 (1.53)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e84.78 (1.53)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.147\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.259\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInsulin (\u0026micro;U/mL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.38 (1.29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7.66 (1.29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.843\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.373\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin D (ng/mL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e14.74 (1.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18.52 (1.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.070\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.043*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVitamin B12 (ng/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e105.80 (12.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e172.16 (12.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTSH (mIU/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.30 (1.12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.89 (1.12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.002*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFree T4 (ng/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.80 (0.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.82 (0.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.777\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.629\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHOMA-IR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.03 (0.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.69 (0.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.853\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e.496\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eSE: Standard Error; *One-way MANCOVA is significant at the \u003cem\u003eP\u003c/em\u003e \u0026lt; .05 level (2-tailed). a: Covariates appearing in the model are evaluated at the following values; age = 24.05, BMI = 22.94, gender = 1.50, alcohol = 1.35\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThere was no significant difference between the case group and the control group in terms of glycemic parameters. However, HOMA-IR values were higher in the case group while HbA1C values were higher in the control group (Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe fact that the alcohol use rate was lower and the average age was higher in the case group in comparison to the control group, indicates that randomization was not performed very well. However, this limitation has been minimized by one-way MANCOVA analyzes performed by considering covariance factors such as age, gender, BMI and alcohol use.\u003c/p\u003e \u003cp\u003eIn our study, the higher values of serum AST, ALT, and GGT ​​observed in the case group indicates that smoking affects liver and bile functions, negatively. In the literature there are studies that support our results. In a study conducted on males, GGT was higher in smokers in comparison to non-smokers [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. It has also been suggested that smoking causes cellular damage by causing oxidative stress and ultrastructural changes on hepatocytes [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn our study, the lower serum vitamin D values ​​in the case group compared to the control group may be caused by a defect in the vitamin D synthesis in the liver and / or an absorption disorder. Cholecalciferol synthesized in the epidermis or taken with diet turns into 25-hydroxycholecalcidiol in the liver and then to 1,25-hydroxycholecalcitriol as the active form in the kidney [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The 25-hydroxycholecalcididol transformation that takes place in the liver may be impaired due to the negative effects of smoking on hepatocytes. In addition, absorption of Vitamin D, a fat-soluble molecule, may be impaired due to the negative effects of smoking on the biliary system. In the literature, there are a few studies supporting our results, related to vitamin D in our study. However, the reasons for vitamin D deficiency in smokers have not been fully clarified in these studies [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWe found that, serum vitamin B12 values ​​were lower in the case group compared to the control group. These our results are in line with the knowledge in the literature. There are studies suggesting that smoking, which is a source of free radicals, causes serum vitamin B12 levels to decrease [\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. The use of tobacco causes the serum cyanide level to increase due to the cyanide it contains. It has been shown that high cyanide levels increase the excretion of thiocyanate from the kidneys, which is associated with a decrease in serum vitamin B12 level [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWe found that serum TSH levels were lower in the case group compared to the control group. In the literature, it has been reported that the effects of smoking on thyroid tissue are complex, while smoking generally increases susceptibility to hypertroidism [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. This relationship between smoking and thyroid functions may be due to vitamin B12 deficiency seen in smokers. Although there is a widespread opinion in the literature that vitamin B12 deficiency and increased levels of homocysteine ​​increase susceptibility to hypothyroidism and autoimmune thyroid diseases, studies on animals suggest contradictory evidence [\u003cspan additionalcitationids=\"CR20\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. In addition, S adenosyl methionine, a product of the homocysteine ​​methionine cycle with additive vitamin B12 cofactor stimulates TRH and therefore TSH release and TSH receptor interaction [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn our study, we found no difference in kidney function, between smokers and non-smokers. In the literature, it has been reported that kidney functions are affected by smoking due to the increase in nicotine-induced adrenergic activity [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn our study, no significant difference was found between smokers and non-smokers in terms of serum glycemic index and lipid profile. However, HOMA-IR values were higher in the case group while HbA1C values were higher in the control group. HOMA-IR values show the momentary state, while HbA1C shows the last three-month period. These findings indicate that there was a predisposition to hypoglycaemia in the smoker group in the past. In a study conducted on obese people, HOMA-IR was found to be higher in smokers compared to non-smokers, but there was no significant difference in serum glucose, insulin, total cholesterol, triglyceride, HDL-C, and LDL-C levels [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Nicotine causes hyperglycemia by increasing gluconeogenesis by stimulating catecholamine-mediated glucagon release from the adrenergic medulla [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. It is plausible that the relationship between smoking and insulin resistance, which is frequently emphasized in the literature, may be a result rather than a cause. Given the assumption that hyperinsullinemia-induced hypoglycaemia episodes seen at the onset of type 2 diabetes can be prevented by increasing gluconeogenesis, nicotine may be preferred due to an avoidance behavior.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eAs a result, we suggest that smoking has a negative effect on liver and bile functions, and vitamin D values ​​are affected secondary to this negative effect. In addition, the relationship between smoking and thyroid functions may be due to vitamin B12 deficiency seen in smokers.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBMI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBbody mass index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAST\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAspartate aminotransferase\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eALT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAlanine aminotransferase\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGGT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGamma-glutamyl transferase\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHDL-C\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHigh-density lipoprotein cholesterol\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLDL-C\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLow-density lipoprotein cholesterol\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTSH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eThyroid stimulating hormone\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHbA1C\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGlycosylated hemoglobin\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHOMA-IR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHomeostatic model assessment for insulin resistance\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTRH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eThyrotropin releasing hormone\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe concept and design of the study: Y.S. and S.B.; Data acquisition: Y.S., S.B. and A.P.; Statistical analysis: Y. S.; Analyzed the data and drafted the manuscript: Y.S., S.B. and A.P. All authors read and approved the final version of the manuscript\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere is no funding\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe dataset is available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was approved by the Istanbul Training Research Hospital Clinical Research Ethics Committee (Decision no: 2153). Informed consent was not obtained because of retrospective study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that no conflicts of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eTalhout R, Schulz T, Florek E, Benthem JV, Wester P, Opperhuizen A. Hazardous compounds in tobacco smoke. Int J Environ Res Public Health. 2011;8:613\u0026ndash;28.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBenowitz NL, Henningfield JE. Reducing the nicotine content to make cigarettes less addictive. Tob Control. 2013;22:14\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSalvi S. Tobacco smoking and environmental risk factors for chronic obstructive pulmonary disease. Clin Chest Med. 2014;35(1):17\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaniado-Labor\u0026iacute;n R. Smoking and chronic obstructive pulmonary disease (COPD). Parallel epidemics of the 21st century. Int J Environ Res Public Health. 2009;6:209\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBanks E, Joshy G, Korda RJ, Stavreski B, Soga K, Egger S. etal.Tobacco smoking and risk of 36 cardiovascular disease subtypes: fatal and non-fatal outcomes in a large prospective Australian study. BMC Med. 2019;17(1):128.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMessner B, Bernhard D. Smoking and cardiovascular disease: mechanisms of endothelial dysfunction and early atherogenesis. Arterioscler Thromb Vasc Biol. 2014;34(3):509\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee H, Joe KH, Kim W, Park J, Lee DH, Sung KW. etal.Increased leptin and decreased ghrelin level after smoking cessation. Neurosci Lett. 2006;409(1):47\u0026ndash;51.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFagard RH, Nilsson PM. Smoking and diabetes-The double health hazard! Primary care diabetes. 2009;3:205\u0026ndash;09.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee D, Kang HW, Kim II. Association between cigarette smoking and serum gamma glutamyl transferase level. Int J Respir Pulm Med. 2019;6:125. Y.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBattah KA, Badran DH, Shraideh ZA. Effect of cigarette smoking on the structure of hepatocytes: TEM study. Int J Morphol. 2016;34(4):1239\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHeath KM, Elovic EP. Vitamin D deficiency: Implications in the rehabilitation setting. Am J Phys Med Rehabil. 2006;85:916\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrot C, Jorgensen NR, Sorensen OH. The influence of smoking on vitamin D status and calcium metabolism. Eur J Clin Nutr. 1999;53(12):920\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePivathilake HJ, Macaluso M, Hine RJ, Richards EW, Krumdieck CL. Local and systemic effects of cigarette smoking on folate and vitamin B12. Am J Clin Nutr. 1994;60:559\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcgarry JM, Andrews J. Smoking in pregnancy and vitamin B12 metabolism. BMJ. 1972;2:74\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSezgin Y. Approach to Vitamin B12 Deficiency. Konuralp Medical J. 2019;11(3):482\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLinnell JC, Smith AD, Smith CL, Wilson J, Matthews DM. Effects of smoking on metabolism and excretion of vitamin B12. BMJ. 1968;2:215\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG\u0026uuml;lc\u0026uuml; F, Polat SA, G\u0026uuml;rs\u0026uuml; MF. Aşırı sigara kullanımının tiroid fonksiyon testleri ile eser element d\u0026uuml;zeylerine etkileri. Turkiye Klinikleri J Med Sci. 2003;23(5):386\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim BH, Kim WB, Kim TY, Kim HK, Jeon SH, Lee CW. etal.Association between Cigarette Smoking and Thyroid Function in Adults without Previous History of Thyroid Disease. Endocrinol Metab. 2008;23(2):123\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCollins AB, Pawlak R. Prevalence of vitamin B12 deficiency among patients with thyroid dysfunction. 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Indian J Med Res. 2006;124(3):261\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYağbasan Y, Ersoy C, \u0026Ccedil;ubuk\u0026ccedil;u E, \u0026Ouml;lmez \u0026Ouml;F, İmamoğlu Ş. Morbid obez kadınlarda sigara i\u0026ccedil;iminin obezite indeksleri, ins\u0026uuml;lin direnci, kan basıncı, glisemi ve lipid parametreleri \u0026uuml;zerine etkilerinin retrospektif olarak değerlendirilmesi. İn\u0026ouml;n\u0026uuml; \u0026Uuml;niversitesi Tıp. Fak\u0026uuml;ltesi Dergisi. 2008;15(4):245\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Smoking tobacco, Biochemical parameters, metabolism","lastPublishedDoi":"10.21203/rs.3.rs-982021/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-982021/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eSmoking tobacco is a substantial risk factor for chronic obstructive pulmonary disease and cardiovascular diseases. For this reason, studies on smoking are mostly focused on the pulmonary and cardiovascular systems. Recently, an increase has been observed in the number of studies investigating the relationship between obesity and diabetes and smoking. We investigated the effects of smoking on other serum biochemical parameters and metabolism.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis is a case-control study. The case and control groups were formed by clinical randomization by using the data obtained from the hospital information system and patient records, including age, gender, height, and weight. Smokers were identified as the case group, while non-smokers were identified as the control group. In the comparisons of rates Chi-square tests were used and in the comparisons of averages, independent sample t and MANCOVA tests were used.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eWhen covariance factors such as age, gender, body mass index, and alcohol use were taken into consideration, It found that AST, ALT, and GGT were higher in smokers, whereas vitamin D, vitamin B12, and TSH were higher in non-smokers.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eWe found that smoking has a negative effect on liver and bile functions, and vitamin D values ​​are affected secondary to this negative effect.\u003c/p\u003e","manuscriptTitle":"Evaluation of Serum Biochemical Parameters and Metabolism in Smokers: A Case Control Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-02-08 15:41:05","doi":"10.21203/rs.3.rs-982021/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7f5398bf-a4d5-4b31-9e97-706916fa431d","owner":[],"postedDate":"February 8th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2022-02-08T15:41:05+00:00","versionOfRecord":[],"versionCreatedAt":"2022-02-08 15:41:05","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-982021","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-982021","identity":"rs-982021","version":["v1"]},"buildId":"cBFmMYwuxLRRLfASyISRj","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}