The relationships between bariatric surgery and sexual function: current evidence based medicine

The relationships between bariatric surgery and sexual function: current evidence based medicine | 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 The relationships between bariatric surgery and sexual function: current evidence based medicine Shengzhuo Liu, Dehong Cao, Zhengju Ren, Jinze Li, Lei Peng, Qin Zhang, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.2.11854/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 02 Oct, 2020 Read the published version in BMC Urology → Version 1 posted 10 You are reading this latest preprint version Abstract Background Controversial remains despite several studies have discussed the role of bariatric surgery for ameliorating male’s sexual function. This study aims to evaluate the efficacy of bariatric surgery in promoting male`s erectile function. Methods We performed a systematic review according to PubMed, EMbase, The Cochrane Library, CNKI and Clinical Trails.gov searching for eligible studies and conducted a meta-analysis to compare the International Index of Erectile Function (IIEF) score or Brief Male Sexual Function Inventory (BSFI) score preoperatively and postoperatively. Results 11 articles were included in this study. The meta-analysis showed bariatric surgery was associated with significantly improvement in the IIEF score (erectile function: MD = 5.33, 95% CI 4.12-6.54; intercourse satisfaction: MD = 2.57, 95% CI 1.19-3.94; orgasmic function: MD = 0.50, 95%CI 0.60-0.94; overall satisfaction: MD = 1.67, 95% CI 0.78-2.56; sexual desire: MD = 1.27, 95% CI 0.61- 1.93; total erectile function: MD = 7.21, 95% CI 4.33-10.10) and the BSFI score (erection: MD =2.53, 95% CI 2.39-2.67; ejaculation: MD = 1.40, 95% CI 1.28-1.51; desire: MD =1.40, 95% CI 1.32-1.49; problem assessment: MD = 2.20, 95% CI 2.06-2.34; sexual satisfaction: MD = 0.70, 95% CI 0.60-0.76). Conclusions To our knowledge, although the mechanism how Bariatric surgery helps improving male s erectile function is not well interpreted yet, it s supported by our results that bariatric surgery may be effective in sexual function promoting for obese individuals. Urology & Nephrology Bariatric surgery Obesity Erectile function Sexual function Sex hormone Meta-analysis Figures Figure 1 Figure 2 Figure 3 Background Erectile dysfunction, one of the most complained problems during sexual intercourse, is the inability to achieve or maintain an erection sufficient for satisfactory sexual performance[1], which has been paid more and more attention by society for its` association with poor quality of male`s sexual life[2] and the prevalence goes higher and higher during the past decade. Epidemiological studies indicate that in 1995 erectile dysfunction (ED) affected over 150 million men worldwide and the prevalence will reach 322 million by 2025[3]. Heathy problems, including sexual dysfunction that is highly prevalent in the general population, impaired the quality of life[4]. Obesity, especially morbid obesity, is associated with a broad range of medical and psychosocial comorbidities which impose a negative effect on patients’ lives and health-care systems, including non-insulin dependent diabetes mellitus, coronary heart disease, stroke and hypertension[5-8]. Evidence from a large number of studies have shown relationships between obesity and derangements in sexual functioning[9-11], which was often overlooked referred to the comorbidities of obesity. Some scholars have studied the effects of obesity on men in various aspects, especially in terms of sexual function, which deserves our attention. It was reported that ED was observed a higher morbidity in obese males compared with in males of normal weight[12]. Sarwer et[11] aldemonstrated in their study that 36% of men presenting for bariatric surgery reported erectile dysfunction, which is in contrast to 20% of men who sought nonsurgical weight loss and reported ED. Moore et al[13] have reported 45% of obese men who seek weight reduction met diagnostic criteria of erectile dysfunction. Laumann et al[4] reported in the United States that the prevalence of sexual dysfunction in general male population was 31%. Several managements have been implemented to deal with obesity. Dietary intervention, medications, physical exercise are widely used in case of mild and moderate obesity[14]. Meanwhile, bariatric surgery has become the most effective treatment method for morbid obese patients which can bring great weight reduction obviously and ameliorate the comorbidities[15, 16]. The bariatric surgical procedures, including gastric bypass, vertical sleeve gastrectomy, and biliopancreatic diversion, are recommended for class 2 obesity associated with comorbidities and for class 3 obesity (body index[BMI] 35-39.9kg/m² and >40kg/m²;respectively)[17]. As proved an effective procedure in promoting weight loss and improving obesity-related physical comorbidities, bariatric surgery is now widely performed on obese patients[18-21]. Results of some studies have revealed the bariatric surgery has a significant positive effect on male’s sexual function while some studies showed no significant change. The number of studies into the relationship between obesity and male’s sexual dysfunction is limited and the results have been controversial. Hence, we performed the systemic review and meta-analysis to investigate the efficiency of bariatric surgery in promoting male’s sexual function. Methods Before conducting a systematic literature search, we formulated a protocol to standardize the process of literature review and data extraction which is strictly compliance during the procedure. Inclusion and Exclusion Criteria Two independent reviewers separately assessed each study based on the inclusion and exclusion criteria to determine whether the study be included. Studies that met the following criteria were included: (1) self-control study, (2) randomized controlled trials which set bariatric surgery as intervention, (3) at least one of the indexes listed above for evaluating male`s sexual function (IIEF score and BSFI score ) was assessed in the study. For exclusion, we eliminated studies which met the following criteria: (1) only females were recruited as the study subjects, (2) either perioperative data or postoperative data was missing or not recorded, (3) indexes used to evaluate sexual function didn`t correlate with our study, (4) reviews, letters, technical reports, case reports, comments or studies consisting of <10 controls. Publications based on the same study (e.g. same authors, institutions, period of study) were discussed, and only the best-quality study was used. Search Strategy We searched PubMed, EMbase, The Cochrane Library, CNKI and Clinical Trails.gov for English-language studies published before May 2019. Search terms included bariatric, laparoscopic Roux-and-Y gastric bypass, gastric bypass surgery, obesity, erectile dysfunction and sexual function. Supplements retrieved by manually reviewing the references of the included articles enabled us to build a comprehensive analysis. Study Selection Two reviewers independently reviewed the titles and abstracts of all retrieved studies for identification of potentially relevant systematic reviews. The full texts of studies which are deemed to be relevant studies were reviewed in details after the initial screening. Data Extraction For each included systematic review, we extracted data by two independent reviewers including lead author, country, patients composition, methods for recruitment, baseline IIEF (or BSFI) score, postoperative IIEF (or BSFI) score and postoperative time point for SF assessment. We used the five-question International Index of Erectile Function (IIEF-5) score and BFSI score before and after bariatric surgery as the main reference index to evaluate the erectile function. Quality Assessment We used a modified version of the methodological index for non-randomized studies’ (MINORS[[22, 23]: Table 3) checklist to assess methodological quality of the included systematic reviews. The checklist contains the following 8 aspects: (1) a clearly stated aim, (2) inclusion of consecutive patients, (3) prospective collection of data, (4) endpoints appropriate to the aim of the study, (5) unbiased assessment of the study endpoint, (6) follow-up period appropriate to the aim of the study, (7) loss to follow up less than 5%, (8) prospective calculation of the study size. Data Analysis We perform the meta-analysis by using the Cochrane Review software (Review manager v.5.3 for windows). To analysis the categorical cariables, the Cochran-Mantel-Haenszel test was conducted and the forest plots was performed to show the results. Heterogeneity analysis uses the I 2 test to define the statistic heterogeneity between each study. The heterogeneity was deemed to be acceptable and fixed model was used if the I 2 was less than 50%, while the heterogeneity was considered high and the random model was used if the I 2 was greater than 50%. Results Study selection We identified 279 studies totally. After the initial screening through the titles and abstracts, we assessed the full-test articles eligibly for detailed assessment. Finally, 11 studies met the inclusion criteria and were included in the research. The flowchart of the procedure is shown in Fig.1. Characteristics of the included studies Of the total 11 studies that are included in our studies, the details of the studies are presented in Table 1. Results of each study Results of studies which dedicated to investigate the changes in self-reported sexual function on obese patients who underwent bariatric surgery, have been controversial and were illustrated in Table 2. Sarwer et al.[11] conducted a prospective cohort study, containing 32 man who underwent a Roux-en-Y gastric bypass, and investigated the sexual function of individuals by using the International Index of Erectile Functioning (IIEF) and sex hormones. The results showed that there was no significant change of the sexual function from the baseline except of overall satisfaction at prospective year 3 (P = 0.008), though the men reported improvements in sexual functioning. On the contrary, the prospective cohort study performed by Reis et al[24]. studied 10 morbidly obese men to measure the degree to sexual function change after life style modifications (exercise and diet) for 4 months and subsequently gastric bypass. Weight loss associated with bariatric surgery was found to improve erectile function quality in the research. Ranasinghe et al[25]. investigated the effects of weight loss and laparoscopic gastric banding surgery on sexual function among 20 obese men. The results suggested that the IIEF score achieve an improvement significantly after surgery while there existed worsening of erectile index (P = 0.005) and orgasmic function (P=0.002). In a prospective study, Mora et al[26]. found the IIEF score increased significantly after 1 year by investigating 39 men undergoing bariatric surgery. Meanwhile, Li et al[27]., conducting a retrospective cohort study, found a significant improvement in IIEF score of 39 obese men after RYGB. Groutz et al[28]. enrolled 39 consecutive obese man, undergoing a laparoscopic sleeve gastrectomy, to investigate the effect of bariatric surgery on male’s sexual function in a prospective study. The IIEF were completed preoperatively and postoperatively. The results demonstrated that male’s sexual function, including erectile function, overall intercourse satisfaction and overall satisfaction, was significantly improved. Meanwhile, the main finding of the prospective study, performed by Efthymious et al.[14], was that the bariatric surgery could lead to a significant improvement in sexual functioning and especially could be find in the first 6 months postoperatively. In a prospective study of bariatric surgery, which used the IIEF score respectively, Aleid et al[29]. similarly find significant improvements in male erectile function. Araujo et al[30]. examined the changes following Fobi-Capella gastroplasty in the quality of male’s sexual life on 21 men with morbid obesity and favorable changes occurred in sexual function postoperatively. Dallal et al[31]. compared the Brief Male Sexual Function Inventory (BSFI) before and after gastric bypass surgery to measure its effect to the sexual function in morbidly obese man. On average, the patients reported a significant increase in all domains of BSFI scores post-operatively, compared with preoperative score. Goitein et al[32]. found the BSFI scores in males increased but did not reach statistical significance (P = 0.08). However, general satisfaction, erection and desire were significantly improved within BSFI. Meta-analysis 279 articles were yielded by our initial search, of which 268 remained after 11 duplicates were removed. Two interviewers independently check these articles and found 11 articles met our inclusion criteria and finally 9 contain the necessary data for quantitative analysis. The analysis was based on 370 patients from 11 studies with 3 to 24 months follow-up that measured male`s sexual function preoperatively and postoperatively. In these studies[11, 14, 24, 26-30], the erectile function was found a 5.33-point increase significantly (Fig 2A 95% CI 4.12-6.54, p < 0.001) while there was a 2.57-point increase in the intercourse satisfaction (Fig 2B 95% CI 1.19-3.94, p = 0.0002), a 0.50-point increase in orgasmic function (Fig 2C 95%CI 0.60-0.94, p = 0.03), a 1.67-point increase in overall satisfaction (Fig 3A 95% CI 0.78-2.56, p = 0.0002), a 1.27-point increase in sexual desire (Fig 3B 95% CI 0.61- 1.93, p = 0.0001) in those studies[11, 14, 24, 26-30]. Meanwhile, total erectile function showed a 7.21-point increase in these studies (Fig 3C 95% CI 4.33-10.10, p < 0.001). The above articles all used the IIEF as the index to measure the sexual function. However, the articles[33, 34] which used BSFI as the index suggested a 2.53-point increase in erection (95% CI 2.39-2.67, p < 0.001), a 1.40-point increase in ejaculation (95% CI 1.28-1.51, p < 0.001), a 1.40-point increase in desire(95% CI 1.32-1.49, p < 0.001) a 2.20-point increase in problem assessment (95% CI 2.06-2.34, p < 0.001) and a 0.70-point increase in sexual satisfaction (95% CI 0.60-0.76, p < 0.001). Discussion Obesity has been a worldwide epidemic and can adversely affect sexual functioning. In the Massachuster Male Aging Study[31], the average prevalence of erectile dysfunction in men who were not overweight was 13% while the altered prevalence in those who were overweight at baseline was 22%. Nowadays, the bariatric surgery has become the predominant treatment for morbid obesity and is reported to be the most effective option for weight loss in the severely obese people who have excessive fat accumulation[35]. The previous studies have documented favorable clinical outcomes after bariatric surgery which can lose weight effectively and bring significant specific-disease reduction in the risk of death[18]. However, relevant researches, investigating the correlation between the bariatric surgery and male`s sexual function, are insufficient. Meanwhile, the definitive causal link between bariatric surgery and male’s sexual function has not been widely researched. Moreover, some relevant studies which investigate the effect of bariatric surgery on male’s sexual function of morbidly obese patients are somewhat limited by lacking of sample sizes, indefinite results, and are low credibility. Thus, we performed the meta-analysis to get a comprehensive evaluation and quantitative analysis of those studies in order to investigate whether bariatric surgery contribute to get improvements on male`s erectile function. To our knowledge, this is the first meta-analysis to include the effect of bariatric surgery on male’s sexual function with both IIEF scores and BSFI scores. Though there exists a meta-analysis that investigate the impact of bariatric surgery on erectile function. Glina et al.[33] only use the IIEF score to analysis and their including studies are 7 while our meta-analysis use 2 score indexes and the enrolled studies are 11. The meta-analysis results indicate that bariatric surgery presents conspicuously effective improvements on male’s sexual function by comparing IIEF scores, including erectile function, intercourse satisfaction, overall satisfaction, orgasmic function, sexual desire, total erectile function and BSFI scores, including erection, ejaculation, problem assessment, sexual satisfaction. According to Aleid et al.[29], the male’s sexual function improvements caused by bariatric surgery resulting in increasing all the IIEF domains, which agree with the study performed by Efthymious et al.[14] and other researches[24, 26, 27]. In contrast, studies undertook by Ranasinghe et al. [25]and Sarwer et al. [11], which also used IIEF to detect male’s sexual function, found no effective improvements reaching statistically significance among obese man undergoing bariatric surgery. Dallal et al.[31], retrospectively studying 97 obese men who had undergone gastric bypass surgery with the mean postoperative follow-up length (19 months). In the study, they addressed that scores improved on all domains of the BSFI postoperatively including sexual drive, erectile function, ejaculatory function and sexual satisfaction by completing the BSFI preoperatively and post-operatively. Meanwhile, the postoperative BSFI scores approached the reference controls. This is in accordance with our findings in which all the domains reached significant improvements. However, the underlying mechanism of obesity-related sexual dysfunction is multifactorial. Previous studies suggested that psychological and social appearance, such as body image, depression and so on, have a negative impact on self-esteem and the tendency of avoidance and initiation to sexual behavior[34]. Negative effect of the comorbidities in obese people (diabetes, hypertension, metabolic syndrome, etc.) have already been clearly associated with sexual dysfunction[10, 31, 36]. A correlation of sex hormones to sexual function has also been confirmed that obesity has a link with sexual dysfunction[37, 38]. Meanwhile, a number of biological mechanisms might account for the connection between obesity and sexual dysfunction. Obesity is a condition of inflammation and chronic oxidative stress[39]. It was suggested that obesity is linked to endothelial dysfunction and increased serum concentrations of vascular inflammatory makers[40, 41]. The visceral adipose tissue can secrete biochemical modulators and proinflammatory factors, such as IL-6, TNF-α, angiotensinogen, angiotensin-converting enzyme and so on, which can be obviously associated with systemic and peripheral vascular inflammation. However, that can lead to a decrease in NO synthase and NO activity, an increase in adhesion molecules, MCP-1 and M-CSF, finally causing endothelial dysfunction[42-44]. Moreover, the reduced adiponectin levels is confirmed to be connected with endothelial dysfunction[45, 46]. The endothelial dysfunction causes erectile dysfunction by influencing the structural integrity of the vascular bed in the penis and the progress of penile engorgement by reducing the blood flow of penile[47]. It can ameliorate endothelial function by increasing vasodilation in which the endothelium plays an important role, increasing the level of activation marks of endothelium and decreasing the level of proinflammatory factor when obese patients proceed to loss weights[48]. Furthermore, the sex hormones have considerable correlation with sexual dysfunction. It is reported that the abnormalities in sex hormone regulation and production are related to sexual dysfunction in men[49, 50]. It has been confirmed that androgens are essential to maintain the libido and regulate erectile capacity in man[51]. But BMI is negatively associated with serum testosterone in some studies. It was estimated that a reduction in free testosterone of 1.35pg/mL and a reduction in total testosterone of 11.79 ng/dL while the weight increases 4.5 kg[52]. There are studies found a positive relationship between estradiol levels and BMI index in men[53]. And the reduction of estradiol levels is thought to associate with weight loss. Thus, the feedback inhibition on LH secretion is removed and enhance the testosterone secretion. But the effect of decrease fat mass to increase testosterone is controversial. Bariatric surgery normalized sex hormone levels in both genders[54]. In addition, the comorbidities associated with obesity, such as diabetes, metabolic syndrome, hypertension, coronary heart disease, obstructive sleep apnea, depression and so on, have been clearly risk associated with sexual dysfunction and would ameliorate after bariatric surgery. There are some limitations of our study. (1) Language bias might limit the generalizability of the findings. (2) Patient self-report is the current standard in the study of male sexual function. (3) Included sample sizes are small. (4) The indexes for evaluating male`s sexual function are simple, which mainly are IIEF score and BSFI score are not all included in all studies. (5) The follow-up time is relatively short and the studies lack long-term indexes. Those limitations might lead to the analysis bias and influence the reliability of our study. Conclusion We found that the bariatric surgery can reliably ameliorate male’s sexual dysfunction, which significantly improves IIEF scores and BSFI scores. These results are in accordance with the recent investigations of male who had undergone bariatric surgery and reported significant improvements in male’s sexual function. Considering not only the well-documented quality-of-life benefits of bariatric surgery, but also the improvement in male’s sexual function, bariartic surgery is a more effective treatment for obese patients with sexual dysfunction. Furthermore, futher studies need to make which can include more samples and provide more reliable conclusions. Abbreviations BMI, body mass index; SD, standard deviation; RYGB, Roux-Y gastric bypass; LGB, laparoscopic gastric banding surgery; LSG, laparoscopic sleeve gastrectomy; SG, sleeve gastrectomy; BPD, Biliang pancreatic diversion; BS, bariatric surgery; PS, prospective study; RS, retrospective study; RCT, randomized clinical trail; BSFI, Brief Male Sexual Function Inventory; IIEF, International Index of Erectile Functioning Declarations Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests All authors declared no competing financial interests. Funding This research was funded by the National Natural Science Foundation of China (Grant no. 81370855 and 81200551). Authors’ contributions LSZ, CDH and RZJ carried out the literature search and data extraction, participated in the data analysis and drafted the manuscript. PL and ZJ participated in the study design and performed the statistical analysis. ZQ and CZY participated in the data extraction and statistical analysis. AJZ, YL and LLR conceived of the study and participated in its design and coordination and helped draft the manuscript. All authors read and approved the final manuscript. Ackonwledgements Not applicable. Availability of data and meterials All data generated or analyzed during this study are included in this published. Author details 1 Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China. 2 Department of Urology, Nanchong Central Hospital, The Second Clinical Medical College, North Sichuan Medical College (University), Nanchong, Sichuan, China. 3 Department of Radiology, Chongqing Traditional Chinese Medicine Hospital, Chongqing, China. 4 Department of Evidence-Based Medicine and Clinical Epidemiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China. References Rew KT HJ: Erectile Dysfunction. American family physician 2016, 10(94):820-827. 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Hammoud A, Gibson M, Hunt SC, Adams TD, Carrell DT, Kolotkin RL, Meikle AW: Effect of Roux-en-Y gastric bypass surgery on the sex steroids and quality of life in obese men. J Clin Endocrinol Metab 2009, 94(4):1329-1332. A V: Decreased androgen levels and obesity in men. Annals of medicine 1996, 1(28):13-15. Rao SR, Kini S, Tamler R: Sex hormones and bariatric surgery in men. Gend Med 2011, 8(5):300-311. Moher D, Liberati A, Tetzlaff J, Altman DG: Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. International journal of surgery (London, England) 2010, 8(5):336-341. Figure Legends Fig. 1 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 flow diagram[55] Fig. 2 Meta-analysis on the efficiency of bariatric surgery in promoting male’s sexual function. Comparison of Erectile Function domain of IIEF (A), Intercourse Satisfaction domain of IIEF (B), and Orgasmic Function domain of IIEF (C) Fig. 3 Meta-analysis on the efficiency of bariatric surgery in promoting male’s sexual function. Comparison of Overall Satisfaction domain of IIEF (A), Sexual Desire domain of IIEF (B), and Total Erectile Function domain (C) Supplementary Files supplement1.pdf Cite Share Download PDF Status: Published Journal Publication published 02 Oct, 2020 Read the published version in BMC Urology → Version 1 posted Editorial decision: Major revision 08 Jan, 2020 Review # 2 received at journal 02 Jan, 2020 Reviewer # 2 agreed at journal 03 Dec, 2019 Review # 1 received at journal 29 Aug, 2019 Reviewers invited by journal 26 Aug, 2019 Reviewer # 1 agreed at journal 26 Aug, 2019 Editor assigned by journal 07 Aug, 2019 Submission checks completed at journal 19 Jul, 2019 Editor invited by journal 19 Jul, 2019 First submitted to journal 04 Jul, 2019 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. 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20:56:44","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":174301,"visible":true,"origin":"","legend":"Meta-analysis on the efficiency of bariatric surgery in promoting male’s sexual function. Comparison of Erectile Function domain of IIEF (A), Intercourse Satisfaction domain of IIEF (B), and Orgasmic Function domain of IIEF (C)","description":"","filename":"figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-2670/v1/figure_2.png"},{"id":2618132,"identity":"f1e45037-f4a2-4a1c-99a6-fd15633f580d","added_by":"ab479129-e11f-4ca8-a227-45a443fbaf92","created_at":"2020-09-25 20:56:44","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":163498,"visible":true,"origin":"","legend":"Meta-analysis on the efficiency of bariatric surgery in promoting male’s sexual function. Comparison of Overall Satisfaction domain of IIEF (A), Sexual Desire domain of IIEF (B), and Total Erectile Function domain (C)","description":"","filename":"figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-2670/v1/figure_3.png"},{"id":13469320,"identity":"e29ce9ad-21f3-4203-a0aa-b2782ae3f8d3","added_by":"auto","created_at":"2021-09-16 21:01:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":660545,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2670/v1/6c858309-aa7a-4236-a412-decdb2700c57.pdf"},{"id":2618134,"identity":"b057b21a-e14c-491a-a107-290bc072708c","added_by":"ab479129-e11f-4ca8-a227-45a443fbaf92","created_at":"2020-09-25 20:56:44","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":227525,"visible":true,"origin":"","legend":"","description":"","filename":"supplement1.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2670/v1/supplement_1.pdf"}],"financialInterests":"","formattedTitle":"The relationships between bariatric surgery and sexual function: current evidence based medicine","fulltext":[{"header":"Background","content":"\u003cp\u003eErectile dysfunction, one of the most complained problems during sexual intercourse, is the inability to achieve or maintain an erection sufficient for satisfactory sexual performance[1], which has been paid more and more attention by society for its` association with poor quality of male`s sexual life[2] and the prevalence goes higher and higher during the past decade. Epidemiological studies indicate that in 1995 erectile dysfunction (ED) affected over 150 million men worldwide and the prevalence will reach 322 million by 2025[3]. Heathy problems, including sexual dysfunction that is highly prevalent in the general population, impaired the quality of life[4].\u003c/p\u003e\n\u003cp\u003eObesity, especially morbid obesity, is associated with a broad range of medical and psychosocial comorbidities which impose a negative effect on patients\u0026rsquo; lives and health-care systems, including non-insulin dependent diabetes mellitus, coronary heart disease, stroke and hypertension[5-8]. Evidence from a large number of studies have shown relationships between obesity and derangements in sexual functioning[9-11], which was often overlooked referred to the comorbidities of obesity. Some scholars have studied the effects of obesity on men in various aspects, especially in terms of sexual function, which deserves our attention. It was reported that ED was observed a higher morbidity in obese males compared with in males of normal weight[12]. Sarwer et[11] aldemonstrated in their study that 36% of men presenting for bariatric surgery reported erectile dysfunction, which is in contrast to 20% of men who sought nonsurgical weight loss and reported ED. Moore et al[13] have reported 45% of obese men who seek weight reduction met diagnostic criteria of erectile dysfunction. Laumann et al[4] reported in the United States that the prevalence of sexual dysfunction in general male population was 31%.\u003c/p\u003e\n\u003cp\u003eSeveral managements have been implemented to deal with obesity. Dietary intervention, medications, physical exercise are widely used in case of mild and moderate obesity[14]. Meanwhile, bariatric surgery has become the most effective treatment method for morbid obese patients which can bring great weight reduction obviously and ameliorate the comorbidities[15, 16]. The bariatric surgical procedures, including gastric bypass, vertical sleeve gastrectomy, and biliopancreatic diversion, are recommended for class 2 obesity associated with comorbidities and for class 3 obesity (body index[BMI] 35-39.9kg/m\u0026sup2; and \u0026gt;40kg/m\u0026sup2;;respectively)[17].\u003c/p\u003e\n\u003cp\u003eAs proved an effective procedure in promoting weight loss and improving obesity-related physical comorbidities, bariatric surgery is now widely performed on obese patients[18-21]. Results of some studies have revealed the bariatric surgery has a significant positive effect on male\u0026rsquo;s sexual function while some studies showed no significant change. The number of studies into the relationship between obesity and male\u0026rsquo;s sexual dysfunction is limited and the results have been controversial. Hence, we performed the systemic review and meta-analysis to investigate the efficiency of bariatric surgery in promoting male\u0026rsquo;s sexual function.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eBefore conducting a systematic literature search, we formulated a protocol to standardize the process of literature review and data extraction which is strictly compliance during the procedure.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion and Exclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwo independent reviewers separately assessed each study based on the inclusion and exclusion criteria to determine whether the study be included. Studies that met the following criteria were included: (1) self-control study, (2) randomized controlled trials which set bariatric surgery as intervention, (3) at least one of the indexes listed above for evaluating male`s sexual function (IIEF score and BSFI score\u003cstrong\u003e)\u003c/strong\u003e was assessed in the study. For exclusion, we eliminated studies which met the following criteria: (1) only females were recruited as the study subjects, (2) either perioperative data or postoperative data was missing or not recorded, (3) indexes used to evaluate sexual function didn`t correlate with our study, (4) reviews, letters, technical reports, case reports, comments or studies consisting of \u0026lt;10 controls. Publications based on the same study (e.g. same authors, institutions, period of study) were discussed, and only the best-quality study was used.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSearch Strategy\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe searched PubMed, EMbase, The Cochrane Library, CNKI and Clinical Trails.gov for English-language studies published before May 2019. Search terms included bariatric, laparoscopic Roux-and-Y gastric bypass, gastric bypass surgery, obesity, erectile dysfunction and sexual function. Supplements retrieved by manually reviewing the references of the included articles enabled us to build a comprehensive analysis.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy Selection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwo reviewers independently reviewed the titles and abstracts of all retrieved studies for identification of potentially relevant systematic reviews. The full texts of studies which are deemed to be relevant studies were reviewed in details after the initial screening.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Extraction \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor each included systematic review, we extracted data by two independent reviewers including lead author, country, patients composition, methods for recruitment, baseline IIEF (or BSFI) score, postoperative IIEF (or BSFI) score and postoperative time point for SF assessment. We used the five-question International Index of Erectile Function (IIEF-5) score and BFSI score before and after bariatric surgery as the main reference index to evaluate the erectile function.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eQuality Assessment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe used a modified version of the methodological index for non-randomized studies\u0026rsquo; (MINORS[[22, 23]: Table 3) checklist to assess methodological quality of the included systematic reviews. The checklist contains the following 8 aspects: (1) a clearly stated aim, (2) inclusion of consecutive patients, (3) prospective collection of data, (4) endpoints appropriate to the aim of the study, (5) unbiased assessment of the study endpoint, (6) follow-up period appropriate to the aim of the study, (7) loss to follow up less than 5%, (8) prospective calculation of the study size.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe perform the meta-analysis by using the Cochrane Review software (Review manager v.5.3 for windows). To analysis the categorical cariables, the Cochran-Mantel-Haenszel test was conducted and the forest plots was performed to show the results. Heterogeneity analysis uses the I\u003csup\u003e2\u003c/sup\u003e test to define the statistic heterogeneity between each study. The heterogeneity was deemed to be acceptable and fixed model was used if the I\u003csup\u003e2\u003c/sup\u003e was less than 50%, while the heterogeneity was considered high and the random model was used if the I\u003csup\u003e2\u003c/sup\u003e was greater than 50%.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eStudy selection \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe identified 279 studies totally. After the initial screening through the titles and abstracts, we assessed the full-test articles eligibly for detailed assessment. Finally, 11 studies met the inclusion criteria and were included in the research. The flowchart of the procedure is shown in Fig.1.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCharacteristics of the included studies\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOf the total 11 studies that are included in our studies, the details of the studies are presented in Table 1.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults of each study\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eResults of studies which dedicated to investigate the changes in self-reported sexual function on obese patients who underwent bariatric surgery, have been controversial and were illustrated in Table 2.\u003c/p\u003e\n\u003cp\u003eSarwer et al.[11] conducted a prospective cohort study, containing 32 man who underwent a Roux-en-Y gastric bypass, and investigated the sexual function of individuals by using the International Index of Erectile Functioning (IIEF) and sex hormones. The results showed that there was no significant change of the sexual function from the baseline except of overall satisfaction at prospective year 3 (P = 0.008), though the men reported improvements in sexual functioning.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOn the contrary, the prospective cohort study performed by Reis et al[24]. studied 10 morbidly obese men to measure the degree to sexual function change after life style modifications (exercise and diet) for 4 months and subsequently gastric bypass. Weight loss associated with bariatric surgery was found to improve erectile function quality in the research.\u003c/p\u003e\n\u003cp\u003eRanasinghe et al[25]. investigated the effects of weight loss and laparoscopic gastric banding surgery on sexual function among 20 obese men. The results suggested that the IIEF score achieve an improvement significantly after surgery while there existed worsening of erectile index (P = 0.005) and orgasmic function (P=0.002).\u003c/p\u003e\n\u003cp\u003eIn a prospective study, Mora et al[26]. found the IIEF score increased significantly after 1 year by investigating 39 men undergoing bariatric surgery. Meanwhile, Li et al[27]., conducting a retrospective cohort study, found a significant improvement in IIEF score of 39 obese men after RYGB. Groutz et al[28]. enrolled 39 consecutive obese man, undergoing a laparoscopic sleeve gastrectomy, to investigate the effect of bariatric surgery on male\u0026rsquo;s sexual function in a prospective study. The IIEF were completed preoperatively and postoperatively. The results demonstrated that male\u0026rsquo;s sexual function, including erectile function, overall intercourse satisfaction and overall satisfaction, was significantly improved. Meanwhile, the main finding of the prospective study, performed by Efthymious et al.[14], was that the bariatric surgery could lead to a significant improvement in sexual functioning and especially could be find in the first 6 months postoperatively. In a prospective study of bariatric surgery, which used the IIEF score respectively, Aleid et al[29]. similarly find significant improvements in male erectile function.\u003c/p\u003e\n\u003cp\u003eAraujo et al[30]. examined the changes following Fobi-Capella gastroplasty in the quality of male\u0026rsquo;s sexual life on 21 men with morbid obesity and favorable changes occurred in sexual function postoperatively.\u003c/p\u003e\n\u003cp\u003eDallal et al[31]. compared the Brief Male Sexual Function Inventory (BSFI) before and after gastric bypass surgery to measure its effect to the sexual function in morbidly obese man. On average, the patients reported a significant increase in all domains of BSFI scores post-operatively, compared with preoperative score.\u003c/p\u003e\n\u003cp\u003eGoitein et al[32]. found the BSFI scores in males increased but did not reach statistical significance (P = 0.08). However, general satisfaction, erection and desire were significantly improved within BSFI.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMeta-analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e279 articles were yielded by our initial search, of which 268 remained after 11 duplicates were removed. Two interviewers independently check these articles and found 11 articles met our inclusion criteria and finally 9 contain the necessary data for quantitative analysis.\u003c/p\u003e\n\u003cp\u003eThe analysis was based on 370 patients from 11 studies with 3 to 24 months follow-up that measured male`s sexual function preoperatively and postoperatively. In these studies[11, 14, 24, 26-30], the erectile function was found a 5.33-point increase significantly (Fig 2A 95% CI 4.12-6.54, p \u0026lt; 0.001) while there was a 2.57-point increase in the intercourse satisfaction (Fig 2B 95% CI 1.19-3.94, p = 0.0002), a 0.50-point increase in orgasmic function (Fig 2C 95%CI 0.60-0.94, p = 0.03), a 1.67-point increase in overall satisfaction (Fig 3A 95% CI 0.78-2.56, p = 0.0002), a 1.27-point increase in sexual desire (Fig 3B 95% CI 0.61- 1.93, p = 0.0001) in those studies[11, 14, 24, 26-30]. Meanwhile, total erectile function showed a 7.21-point increase in these studies (Fig 3C 95% CI 4.33-10.10, p \u0026lt; 0.001). The above articles all used the IIEF as the index to measure the sexual function. However, the articles[33, 34] which used BSFI as the index suggested a 2.53-point increase in erection (95% CI 2.39-2.67, p \u0026lt; 0.001), a 1.40-point increase in ejaculation (95% CI 1.28-1.51, p \u0026lt; 0.001), a 1.40-point increase in desire(95% CI 1.32-1.49, p \u0026lt; 0.001) a 2.20-point increase in problem assessment (95% CI 2.06-2.34, p \u0026lt; 0.001) and a 0.70-point increase in sexual satisfaction (95% CI 0.60-0.76, p \u0026lt; 0.001).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eObesity has been a worldwide epidemic and can adversely affect sexual functioning. In the Massachuster Male Aging Study[31], the average prevalence of erectile dysfunction in men who were not overweight was 13% while the altered prevalence in those who were overweight at baseline was 22%. Nowadays, the bariatric surgery has become the predominant treatment for morbid obesity and is reported to be the most effective option for weight loss in the severely obese people who have excessive fat accumulation[35]. The previous studies have documented favorable clinical outcomes after bariatric surgery which can lose weight effectively and bring significant specific-disease reduction in the risk of death[18]. However, relevant researches, investigating the correlation between the bariatric surgery and male`s sexual function, are insufficient. Meanwhile, the definitive causal link between bariatric surgery and male\u0026rsquo;s sexual function has not been widely researched. Moreover, some relevant studies which investigate the effect of bariatric surgery on male\u0026rsquo;s sexual function of morbidly obese patients are somewhat limited by lacking of sample sizes, indefinite results, and are low credibility. Thus, we performed the meta-analysis to get a comprehensive evaluation and quantitative analysis of those studies in order to investigate whether bariatric surgery contribute to get improvements on male`s erectile function.\u003c/p\u003e\n\u003cp\u003eTo our knowledge, this is the first meta-analysis to include the effect of bariatric surgery on male\u0026rsquo;s sexual function with both IIEF scores and BSFI scores. Though there exists a meta-analysis that investigate the impact of bariatric surgery on erectile function. Glina et al.[33] only use the IIEF score to analysis and their including studies are 7 while our meta-analysis use 2 score indexes and the enrolled studies are 11.\u003c/p\u003e\n\u003cp\u003eThe meta-analysis results indicate that bariatric surgery presents conspicuously effective improvements on male\u0026rsquo;s sexual function by comparing IIEF scores, including erectile function, intercourse satisfaction, overall satisfaction, orgasmic function, sexual desire, total erectile function and BSFI scores, including erection, ejaculation, problem assessment, sexual satisfaction. According to Aleid et al.[29], the male\u0026rsquo;s sexual function improvements caused by bariatric surgery resulting in increasing all the IIEF domains, which agree with the study performed by Efthymious et al.[14] and other researches[24, 26, 27]. In contrast, studies undertook by Ranasinghe et al. [25]and Sarwer et al. [11], which also used IIEF to detect male\u0026rsquo;s sexual function, found no effective improvements reaching statistically significance among obese man undergoing bariatric surgery. Dallal et al.[31], retrospectively studying 97 obese men who had undergone gastric bypass surgery with the mean postoperative follow-up length (19 months). In the study, they addressed that scores improved on all domains of the BSFI postoperatively including sexual drive, erectile function, ejaculatory function and sexual satisfaction by completing the BSFI preoperatively and post-operatively. Meanwhile, the postoperative BSFI scores approached the reference controls. This is in accordance with our findings in which all the domains reached significant improvements.\u003c/p\u003e\n\u003cp\u003eHowever, the underlying mechanism of obesity-related sexual dysfunction is multifactorial. Previous studies suggested that psychological and social appearance, such as body image, depression and so on, have a negative impact on self-esteem and the tendency of avoidance and initiation to sexual behavior[34]. Negative effect of the comorbidities in obese people (diabetes, hypertension, metabolic syndrome, etc.) have already been clearly associated with sexual dysfunction[10, 31, 36]. A correlation of sex hormones to sexual function has also been confirmed that obesity has a link with sexual dysfunction[37, 38]. Meanwhile, a number of biological mechanisms might account for the connection between obesity and sexual dysfunction. Obesity is a condition of inflammation and chronic oxidative stress[39]. It was suggested that obesity is linked to endothelial dysfunction and increased serum concentrations of vascular inflammatory makers[40, 41]. The visceral adipose tissue can secrete biochemical modulators and proinflammatory factors, such as IL-6, TNF-\u0026alpha;, angiotensinogen, angiotensin-converting enzyme and so on, which can be obviously associated with systemic and peripheral vascular inflammation. However, that can lead to a decrease in NO synthase and NO activity, an increase in adhesion molecules, MCP-1 and M-CSF, finally causing endothelial dysfunction[42-44]. Moreover, the reduced adiponectin levels is confirmed to be connected with endothelial dysfunction[45, 46]. The endothelial dysfunction causes erectile dysfunction by influencing the structural integrity of the vascular bed in the penis and the progress of penile engorgement by reducing the blood flow of penile[47]. It can ameliorate endothelial function by increasing vasodilation in which the endothelium plays an important role, increasing the level of activation marks of endothelium and decreasing the level of proinflammatory factor when obese patients proceed to loss weights[48]. Furthermore, the sex hormones have considerable correlation with sexual dysfunction. It is reported that the abnormalities in sex hormone regulation and production are related to sexual dysfunction in men[49, 50]. It has been confirmed that androgens are essential to maintain the libido and regulate erectile capacity in man[51]. But BMI is negatively associated with serum testosterone in some studies. It was estimated that a reduction in free testosterone of 1.35pg/mL and a reduction in total testosterone of 11.79 ng/dL while the weight increases 4.5 kg[52]. There are studies found a positive relationship between estradiol levels and BMI index in men[53]. And the reduction of estradiol levels is thought to associate with weight loss. Thus, the feedback inhibition on LH secretion is removed and enhance the testosterone secretion. But the effect of decrease fat mass to increase testosterone is controversial. Bariatric surgery normalized sex hormone levels in both genders[54]. In addition, the comorbidities associated with obesity, such as diabetes, metabolic syndrome, hypertension, coronary heart disease, obstructive sleep apnea, depression and so on, have been clearly risk associated with sexual dysfunction and would ameliorate after bariatric surgery.\u003c/p\u003e\n\u003cp\u003eThere are some limitations of our study. (1) Language bias might limit the generalizability of the findings. (2) Patient self-report is the current standard in the study of male sexual function. (3) Included sample sizes are small. (4) The indexes for evaluating male`s sexual function are simple, which mainly are IIEF score and BSFI score are not all included in all studies. (5) The follow-up time is relatively short and the studies lack long-term indexes. Those limitations might lead to the analysis bias and influence the reliability of our study.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eWe found that the bariatric surgery can reliably ameliorate male’s sexual dysfunction, which significantly improves IIEF scores and BSFI scores. These results are in accordance with the recent investigations of male who had undergone bariatric surgery and reported significant improvements in male’s sexual function. Considering not only the well-documented quality-of-life benefits of bariatric surgery, but also the improvement in male’s sexual function, bariartic surgery is a more effective treatment for obese patients with sexual dysfunction. Furthermore, futher studies need to make which can include more samples and provide more reliable conclusions.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eBMI, body mass index; SD, standard deviation; RYGB, Roux-Y gastric bypass; LGB, laparoscopic gastric banding surgery; LSG, laparoscopic sleeve gastrectomy; SG, sleeve gastrectomy; BPD, Biliang pancreatic diversion; BS, bariatric surgery; PS, prospective study; RS, retrospective study; RCT, randomized clinical trail; BSFI, Brief Male Sexual Function Inventory; IIEF, International Index of Erectile Functioning \u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors declared no competing financial interests.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was funded by the National Natural Science Foundation of China (Grant no. 81370855 and 81200551).\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLSZ, CDH and RZJ carried out the literature search and data extraction, participated in the data analysis and drafted the manuscript. PL and ZJ participated in the study design and performed the statistical analysis. ZQ and CZY\u003c/p\u003e\n\u003cp\u003eparticipated in the data extraction and statistical analysis. AJZ, YL and LLR conceived of the study and participated in its design and coordination and helped draft the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAckonwledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and meterials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1 \u003c/sup\u003eDepartment of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China. \u003csup\u003e2 \u003c/sup\u003eDepartment of Urology, Nanchong Central Hospital, The Second Clinical Medical College, North Sichuan Medical College (University), Nanchong, Sichuan, China. \u003csup\u003e3 \u003c/sup\u003eDepartment of Radiology, Chongqing Traditional Chinese Medicine Hospital, Chongqing, China. \u003csup\u003e4 \u003c/sup\u003eDepartment of Evidence-Based Medicine and Clinical Epidemiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eRew KT HJ: Erectile Dysfunction. \u003cem\u003eAmerican family physician \u003c/em\u003e2016, 10(94):820-827.\u003c/li\u003e\n\u003cli\u003eTF L: Erectile dysfunction \u003cem\u003eThe New England journal of medicine \u003c/em\u003e2000, 24(342):1802-1813.\u003c/li\u003e\n\u003cli\u003eAyta IA MJ, Krane RJ: The likely worldwide increase in erectile dysfunction between 1995 and 2025 and some possible policy consequences. \u003cem\u003eBJU international \u003c/em\u003e1999, 1(84):50-56.\u003c/li\u003e\n\u003cli\u003eLaumann EO PA, Rosen RC: Sexual dysfunction in the United States: prevalence and predictors.\u003cem\u003e Jama \u003c/em\u003e1999, 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Comparison of Erectile Function domain of IIEF (A), Intercourse Satisfaction domain of IIEF (B), and Orgasmic Function domain of IIEF (C)\u003c/p\u003e\n\u003cp\u003eFig. 3 Meta-analysis on the efficiency of bariatric surgery in promoting male\u0026rsquo;s sexual function. Comparison of Overall Satisfaction domain of IIEF (A), Sexual Desire domain of IIEF (B), and Total Erectile Function domain (C)\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-urology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"buro","sideBox":"Learn more about [BMC Urology](http://bmcurol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/buro/default.aspx","title":"BMC Urology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Bariatric surgery; Obesity; Erectile function; Sexual function; Sex hormone; Meta-analysis","lastPublishedDoi":"10.21203/rs.2.11854/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.2.11854/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Background\n\nControversial remains despite several studies have discussed the role of bariatric surgery for ameliorating male’s sexual function. This study aims to evaluate the efficacy of bariatric surgery in promoting male`s erectile function.\n\nMethods\n\nWe performed a systematic review according to PubMed, EMbase, The Cochrane Library, CNKI and Clinical Trails.gov searching for eligible studies and conducted a meta-analysis to compare the International Index of Erectile Function (IIEF) score or Brief Male Sexual Function Inventory (BSFI) score preoperatively and postoperatively.\n\nResults\n\n11 articles were included in this study. The meta-analysis showed bariatric surgery was associated with significantly improvement in the IIEF score (erectile function: MD = 5.33, 95% CI 4.12-6.54; intercourse satisfaction: MD = 2.57, 95% CI 1.19-3.94; orgasmic function: MD = 0.50, 95%CI 0.60-0.94; overall satisfaction: MD = 1.67, 95% CI 0.78-2.56; sexual desire: MD = 1.27, 95% CI 0.61- 1.93; total erectile function: MD = 7.21, 95% CI 4.33-10.10) and the BSFI score (erection: MD =2.53, 95% CI 2.39-2.67; ejaculation: MD = 1.40, 95% CI 1.28-1.51; desire: MD =1.40, 95% CI 1.32-1.49; problem assessment: MD = 2.20, 95% CI 2.06-2.34; sexual satisfaction: MD = 0.70, 95% CI 0.60-0.76).\n\nConclusions\n\nTo our knowledge, although the mechanism how Bariatric surgery helps improving male`s erectile function is not well interpreted yet, it`s supported by our results that bariatric surgery may be effective in sexual function promoting for obese individuals.","manuscriptTitle":"The relationships between bariatric surgery and sexual function: current evidence based medicine","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2019-07-23 21:25:24","doi":"10.21203/rs.2.11854/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2020-01-08T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-01-02T12:00:00+00:00","index":2,"fulltext":"Recommendation: Accept after discretionary revisions\nForm responses:\n---\n* Please confirm that you have included your review in the ‘Comments to Author’ box?: ** Yes**\n* Are the methods appropriate and well described to allow independent reproduction of experiments?: **Yes**\n* Does the work include the necessary controls?: **Yes**\n* Are you able to assess the statistics?: ** I have been able to assess all of the statistics in this manuscript (please refer to checklist above)**\n* Are the conclusions drawn adequately supported by the data shown?: **Yes**\n* Quality of written English: **Needs some language corrections before being published**\n* Should the manuscript be highlighted for promotional activity?: **No**\n* Declaration of competing interests: **This reviewer has been recruited by a partner organization, Research Square. Reviewers with declared or apparent competing interests are not utilized for these reviews. This reviewer has agreed to publication of their comments online under a Creative Commons Attribution License attributed to Research Square and was paid a small honorarium for completing the review within a specified timeframe. Honoraria for reviews such as this are paid regardless of the reviewer recommendation.**\n\nComments to Author:\n---\nPEER REVIEWER ASSESSMENTS:\n\nOBJECTIVE - Full research articles: is there a clear objective that addresses a testable research question(s) (brief or other article types: is there a clear objective)?\nYes - there is a clear objective\n\nDESIGN - Is the current approach (including controls and analysis protocols) appropriate for the objective?\nYes - the approach is appropriate\n\nEXECUTION - Are the experiments and analyses performed with technical rigor to allow confidence in the results?\nYes - experiments and analyses were performed appropriately\n\nSTATISTICS - Is the use of statistics in the manuscript appropriate?\nYes - appropriate statistical analyses have been used in the study\n\nINTERPRETATION - Is the current interpretation/discussion of the results reasonable and not overstated?\nYes - the author's interpretation is reasonable\n\nOVERALL MANUSCRIPT POTENTIAL - Is the current version of this work technically sound? If not, can revisions be made to make the work technically sound?\nYes - current version is technically sound\n\nPEER REVIEWER COMMENTS:\n\nGENERAL COMMENTS: Major finding is the association of bariatric surgery and weight loss and ED function and reporting. It would be relevant to understand the relationship of bariatric surgical weight loss to ED functional return. Type of bariatric surgery is important to consider as Roux en Y may cause the most extreme weight loss and possibly the greatest recovery of ED function. Also, is it just weight loss and comparison to other methods of acute weight loss and ED is of interest.\nThis is a very logical literature review and analysis.\n\nREQUESTED REVISIONS:\nI the beginning of the manuscript there are some language improvements that could be made . For example, \"Controversial remains despite several studies have discussed the role of bariatric\nsurgery for ameliorating male's sexual function. This study aims to evaluate the\nefficacy of bariatric surgery in promoting male`s erectile function.\" Controversial is incorrect, they mean that controversy remains. Also, here : \"Conclusions\nTo our knowledge, although the mechanism how Bariatric surgery helps improving\nmale`s erectile function is not well interpreted yet, it`s supported by our results that\nbariatric surgery may be effective in sexual function promoting for obese individuals.\""},{"type":"reviewerAgreed","content":"","date":"2019-12-03T12:00:00+00:00","index":2,"fulltext":""},{"type":"editorInvitedReview","content":"","date":"2019-08-29T12:00:00+00:00","index":1,"fulltext":"Recommendation: Major revisions required\nForm responses:\n---\n* Please confirm that you have included your review in the ‘Comments to Author’ box?: ** Yes**\n* Are the methods appropriate and well described to allow independent reproduction of experiments?: **Yes**\n* Does the work include the necessary controls?: **No**\n* Are you able to assess the statistics?: ** There are statistical tests that I am unable to assess and recommend seeking additional advice (please specify which tests these are in the ‘Comments to Editor’ box)**\n* Are the conclusions drawn adequately supported by the data shown?: **No**\n* Quality of written English: **Not suitable for publication unless extensively edited**\n* Should the manuscript be highlighted for promotional activity?: **No**\n* Declaration of competing interests: **I have no competing interests**\n\nComments to Author:\n---\nThe English needs a complete review throughout.\nSome background on IIEF required to show levels for Mild moderate and severe ED. The Rosen et al European Urol paper 2011 required to demonstrate\"meaningful change in IIEF\", as opposed to statistical change as this differs with severity of ED.\nRef should be made to the EMAS study, especially Camacho et al in EJE 2013, which showed the results of long term weight loss over 4 years. They demonstrated that total T fell, but SHBG fell with weight loss and LH rises. It therefore requires a 15% weight loss to significantly raise free T. There was no suggestion that weight loss significantly improved sexual function. From the same group Antonio et al showed that Free T is most closely associated with symptoms. The authors here, fail to show IIEF change in relation to %weight loss. It could be that those who lost 20-25% body weight showed huge improvements but those losing 10% showed minimal change but the mean was 5 points. The conclusions of the paper might then be different.\n\nThe baseline EF changes suggest that ED was mild to moderate, with perhaps low rates of T2DM and younger age, so perhaps results might not be as good for all comers. I am surprise that these baseline rates were so high as I would expect that for many men with BMIs of over 45 (the mean) sexual activity might be difficult for physical reasons. Were sexually inactive men excluded from the studies.\nRef 25 - I fail to see how IIEF could be improved with EF domain worsened (0.005) and orgasmic function worsened (0.002). This requires explanation or omission.\n\nQuoting MMAS rates of 13% with 22% in obesity - both rates are very low. MMAS was conducted before IIEF, so better to quote more recent population data using IIEF, especially with rates for other co-morbidities, such as 75% in T2DM.\n\nThe discussion does not include body image, low self esteem, as physical disability as factors. Losing weight and improved self esteem might be a factor in making them more likely to be sexually active. Do we know anything about PDE5i use as they felt better .Assuming this to be zero may be wildly inaccurate.\n\nSome discussion required on expense and lack of availability of bariatric surgery. Some health care systems insist on 10% weight loss and a minimum for eligibility prior to surgery meaning that we might be selecting a group more likely to succeed that those simply given dietary advice. A lot of bland statements about bariatric surgery benefits are made but not adequately referenced, and some of the drawbacks should be considered. We would not present a drug meta-analysis without mentioning adverse events.\n\nWhat this meta-analysis fails to show is associated co-morbidities, especially T2DM which would be associated with vascular and neuropathic ED, less reversible with weight loss. As there was no placebo arm, it is vital that we know much more about the baseline co-morbidities ."},{"type":"reviewersInvited","content":"","date":"2019-08-26T12:00:00+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2019-08-26T12:00:00+00:00","index":1,"fulltext":""},{"type":"editorAssigned","content":"","date":"2019-08-07T12:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2019-07-19T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2019-07-19T12:00:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"","date":"2019-07-04T12:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-urology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"buro","sideBox":"Learn more about [BMC Urology](http://bmcurol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/buro/default.aspx","title":"BMC Urology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ae17cb6d-3b5d-4c30-a7a6-6c87a0373642","owner":[],"postedDate":"July 23rd, 2019","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":17899,"name":"Urology \u0026 Nephrology"}],"tags":[],"updatedAt":"2020-10-04T15:02:11+00:00","versionOfRecord":{"articleIdentity":"rs-2670","link":"https://doi.org/10.1186/s12894-020-00707-1","journal":{"identity":"bmc-urology","isVorOnly":false,"title":"BMC Urology"},"publishedOn":"2020-10-02 12:00:00","publishedOnDateReadable":"October 2nd, 2020"},"versionCreatedAt":"2019-07-23 21:25:24","video":"","vorDoi":"10.1186/s12894-020-00707-1","vorDoiUrl":"https://doi.org/10.1186/s12894-020-00707-1","workflowStages":[]},"version":"v1","identity":"rs-2670","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"identity":"rs-2670","version":["v1"]},"buildId":"cBFmMYwuxLRRLfASyISRj","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}