Accuracy of Abott Freestyle Libre versus Dexcom G6 in a patient with pre-diabetes: a case report and review of literature

Accuracy of Abott Freestyle Libre versus Dexcom G6 in a patient with pre-diabetes: a case report and review of literature | 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 Case Report Accuracy of Abott Freestyle Libre versus Dexcom G6 in a patient with pre-diabetes: a case report and review of literature Eiji Kutoh This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3893915/v3 This work is licensed under a CC BY 4.0 License Status: Posted Version 3 posted You are reading this latest preprint version Show more versions Abstract Abbott FreeStyle Libre and Dexcom G6 represent widely employed continuous glucose monitoring (CGM) systems globally. However, their precision remains unexplored concerning postprandial glucose levels in individuals with pre-diabetes following the consumption of diverse dietary regimens. A 58-year-old Japanese man diagnosed with pre-diabetes (postprandial hyperglycemia) underwent simultaneous monitoring using Abbott FreeStyle Libre and Dexcom G6 following the consumption of diverse diets. In the pre-meal state, both systems exhibited comparable and reliable values (around 80–100 mg/dl). However, around 60 minutes following meals containing specific amounts of carbohydrates (approximately above 50 g), FreeStyle Libre demonstrated a more pronounced acceleration in the increase and peak glucose values compared to G6. These discrepancies were further validated through self-monitoring of blood glucose (SMBG) measurements, confirming the less accurate performance of FreeStyle Libre under these conditions. To this end, it appears that fermented products (beans, yogurt, cheese) could suppress postprandial glucose spikes. The study results suggest that, when compared to G6, FreeStyle Libre yielded elevated glucose values and exhibited reduced accuracy in measuring postprandial glucose levels following the ingestion of a specific amount of carbohydrates in a patient with pre-diabetes. pre-diabetes postprandial hyperglycemia CGM FreeStyle Libre G6 Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Continuous Glucose Monitoring (CGM) is an invaluable device for the ongoing assessment of interstitial fluid glucose levels, particularly for individuals undergoing insulin injections. Various CGM systems, utilizing diverse technologies, are currently available or in developmental stages. Comparative studies with self-monitoring blood glucose (SMBG) demonstrate that CGM not only reduces HbA1c but also diminishes the duration and frequency of hypoglycemic events ( 1 ). Presently, two widely utilized systems, Abbott FreeStyle Libre (Abbott, Chicago, USA) and Dexcom G6 (Dexcom, San Diego, USA), have gained prominence worldwide. Notably, these systems eliminate the need for calibration with SMBG ( 2 ). A distinguishing feature of FreeStyle Libre, classified as a flash glucose monitoring (FGM) or intermittently scanned continuous glucose monitoring (isCGM) system, is its ability to continuously measure interstitial fluid glucose levels within the sensor at 15-minute intervals for up to 8 hours. Unlike many other CGM systems, including G6, FreeStyle Libre stores all data internally in the sensor ( 2 ). While the original FreeStyle Libre has been discontinued in some countries, it remains available in others, such as Japan. The newer versions, FreeStyle Libre 2 or 3, are recommended, offering enhancements like alarms for high or low glucose levels and more frequent glucose measurements (every 1 minute). Despite these updates, the fundamental technology remains consistent ( 3 ). Several comparative reports evaluating glucose trends between FreeStyle Libre (original and versions 2) and other CGMs, including G6, in various specific circumstances suggest that FreeStyle Libre is less accurate under certain conditions ( 2 , 4 , 5 , 6 ). To date, there has been no comprehensive investigation involving the simultaneous use and comparison of two different CGM systems in an individual with pre-diabetes subjected to diverse dietary conditions. Prediabetes is characterized by blood glucose levels exceeding the normal range but not reaching the threshold for a diagnosis of type 2 diabetes (T2DM). The initial anomaly in glucose metabolism often manifests as an elevation in postprandial glucose levels due to diminished first-phase insulin secretion. Over time, a progressive decline in beta-cell function contributes to an increase in fasting glucose levels ( 7 , 8 ). Patients with pre-diabetes frequently present as asymptomatic and may not undergo routine examinations. Halting the progression to overt T2DM necessitates the identification of populations at risk for prediabetes, coupled with encouragement for lifestyle modifications, including dietary changes and regular exercise. In such instances, CGM emerges as a highly beneficial method for continuous monitoring of blood glucose levels. In this study, CGM data were collected from a single patient diagnosed with prediabetes, characterized by elevated postprandial glucose levels alongside normal fasting blood glucose (FBG) and HbA1c. The participant concurrently wore both FreeStyle Libre and Dexcom G6 systems, allowing for the simultaneous measurement of glucose levels. The investigation involved monitoring glucose responses following the consumption of various traditional and modern Japanese diets. Case presentation The patient under scrutiny in this report is a 58-year-old male who has exhibited elevated postprandial glucose levels for the past decade. Despite maintaining normal fasting blood glucose and HbA1c levels (ranging from 87–102 mg/dl and 5.4–5.8%, respectively), his post-meal glucose levels vary (ranging from 130–184 mg/dl) depending on dietary choices. One healthcare professional diagnosed him with "pre-diabetes." The patient does not have any other clinically significant disorders and is not currently on any medication. His physical attributes include a height of 179 cm and a weight of 75 kg. To monitor blood glucose levels, the patient had been utilizing FreeStyle Libre and SMBG devices, such as Medisafe Fit Kit (Termo, Tokyo, Japan) or OneTouch Ultra Vue (LifeScan Japan, Tokyo, Japan). However, discrepancies in the data, particularly after meals, have been observed between these devices. To assess the accuracy and reliability of FreeStyle Libre data, the patient opted to simultaneously wear FreeStyle Libre (on the left upper arm) and G6 (on the right lower abdomen). This dual monitoring approach was employed to compare the data gathered after consuming various daily traditional and modern Japanese diets. As a control measure, intermittent SMBG tests were conducted to validate the data acquired from these two distinct CGMs. The FreeStyle Libre CGM has a lifespan of 14 days, whereas the Dexcom G6 CGM is designed for a duration of 10 days. It is empirically recognized within the medical community that the data recorded at the commencement and conclusion of these monitoring periods tends to be less stable. Consequently, in this report, data from day 2 through day 9 following initiation were selectively analyzed. Throughout this period, the individual maintained a calm state and refrained from engaging in excessive physical exercise after meals. The following the details of the CGM apparatus and data. G6 receiver info: SN PG13705811 Transmitter SN 8PE5MM PN 9500-91 LOT 5324787 FreeStyle Libre reader SN JCGX052-T0265 Libre sensor 0m000UJLL AO Figure 1 : With 3 bananas (estimated carbohydrate 45g, started at 7:55), the glucose peak was 162 mg/dl at 9:02 (FreeStyle Libre) and 124 mg/dl at 9:03 (G6). SMBG noted 120 mg/dl at 9:04. Figure 2 : With tofu and natto (fermented beans, estimated carbohydrate 30 g, started at 12:30), the glucose peak was 103 mg/dl at 13:49 (FreeStyle Libre) and 100 mg/dl at 14:13 (G6). SMBG showed 102 mg/dl at 13:55. Figure 3 : With natural yogurt (non-sweetened, 300ml), cheese (4 pieces), and chocolate (estimated carbohydrate 45 g, started at 12:30), the glucose peak was 126 mg/dl at 13:05 (FreeStyle Libre) and 112 mg/dl at 13:04 (G6). SMBG measured 107 mg/dl at 13:08. Figure 4 : With a very big portion of assorted sushi (estimated carbohydrate 200g started at 18:15), the glucose peak was 198 mg/dl at 19:07 (FreeStyle Libre) and 171 mg/dl at 19:09 (G6). SMBG indicated 168 mg/dl at 19:12. Figure 5 : With a big portion of Chinese noodle (estimated carbohydrate 150 g, started at 21:30), the glucose peak was 184 mg/dl at 22:15 (FreeStyle Libre) and 159 mg/dl at 22:18 (G6). SMBG showed 151 mg/dl at 22:19. To validate the aforementioned results, a second trial using new sensors and similar diets was conducted, yielding nearly identical outcomes (results not shown). Discussions Postprandial hyperglycemia not only elevates the relative risk for developing type 2 diabetes (T2DM) but also heightens the likelihood of cardiovascular complications, such as angina, myocardial infarction, or strokes ( 7 , 8 ). The mechanism by which postprandial hyperglycemia contributes to cardiovascular issues involves vascular oxidative stress, endothelial dysfunction, and an inflammatory response ( 7 ). Consequently, it becomes crucial to identify individuals with elevated postprandial glucose levels and implement appropriate interventions. The primary objective of this study was to evaluate the accuracy of the two most widely used CGMs, Abbott FreeStyle Libre and Dexcom G6, in an individual with pre-diabetes characterized by postprandial hyperglycemia. This investigation was prompted by the subject's suspicion regarding the accuracy of FreeStyle Libre, stemming from observed disparities in glucose values compared to SMBG. This report demonstrates that, following the consumption of carbohydrate-rich diets (typically exceeding 40-50g), FreeStyle Libre consistently yielded higher and inaccurate glucose levels compared to reference SMBG data, while G6 provided more reliable glucose values (Figs. 1 , 4 , 5 ). Conversely, pre-meal glucose levels exhibited comparability and accuracy in both devices (Figs. 1 , 2 , 3 , 4 , 5 ). It is imperative for FreeStyle Libre users to exercise caution and validate glucose values with SMBG, particularly in instances involving insulin injection. Furthermore, the applicability of these findings in patients with overt diabetes remains an open question and warrants exploration under various circumstances such as surgical operations, hemodialysis, exercise, or periods of relaxation. Further investigation is needed to ascertain whether similar results would be observed in these diverse scenarios. While the accuracy of FreeStyle Libre, including both the original version and the newer version 2, remains a subject of debate among researchers, particularly when assessed by the Mean Absolute Relative Difference (MARD) ( 2 , 4 , 5 , 6 ), its cost-effectiveness and certain favorable features make it a valuable tool in various scenarios. For instance, it can be particularly useful for comparing the impact of different diets on blood glucose levels, such as comparing the effects of bananas versus oranges or pizza versus pasta. Additionally, it can aid in assessing the peak time after consuming diverse meals. Traditionally, postprandial glucose evaluation is empirically conducted at 2 hours after a meal. However, emerging research suggests that the peak postprandial glucose occurs around 60 minutes after eating ( 9 , 10 ). This time frame (around 60 minutes after meal) might serve as a more relevant predictor for the development of overt diabetes or cardiovascular disorders compared to the 2-hour mark. In the findings presented in this report, the peak glucose levels after meal ingestion were also approximately 60 minutes after ingestion (Figs. 1 , 3 , 4 , 5 ). CGMs may be valuable in comparing the time taken to reach peak glucose levels based on the diet consumed (pasta vs. rice vs. bread). This information can be crucial in determining the optimal timing for post-meal exercise. Yogurt and cheese together with chocolate exhibited minimal glucose spikes in both devices though certain carbohydrates were ingested (Tables 3). This aligns with prior research indicating that dairy products can mitigate glucose excursions after a meal ( 11 ). Tofu and natto, both common Japanese foods derived from fermented soybeans, have been associated with potential protective effects against type 2 diabetes (T2DM) and the suppression of post-meal glucose spikes ( 12 ). In this study, little glucose spikes, if any, were noted with the consumption of tofu and natto (Fig. 2 ). Notably, low-carbohydrate diets are recognized as an effective strategy for controlling post-meal glucose elevation. However, one common challenge with such diets is the potential dissatisfaction of satiety. Remarkably, certain diets utilized in this study, such as tofu, natto, yogurt, cheese, and chocolate, not only exhibited minimal glucose spikes (results not shown as Figure or Table) but also provided a satisfactory level of satiety. In order to corroborate the findings of this study, it is imperative to conduct randomized, controlled dietary intervention trials encompassing diverse diets and a sufficiently large number of subjects. Such trials would shed light on the role of postprandial glycemia. Equally important is the exploration of the time course of postprandial glycemia to gain a comprehensive understanding of its potential impact. Conclusion and recommendation FreeStyle Libre consistently yielded higher and inaccurate postprandial glucose values, while Dexcom G6 demonstrated greater reliability following the ingestion of specific carbohydrate amounts in a person with pre-diabetes. Despite these discrepancies, FreeStyle Libre remains a useful tool for tracking trends in glucose changes. However, for added safety and result verification, occasional confirmation with Self-Monitoring of Blood Glucose (SMBG) is recommended. Ethical considerations Informed consent was obtained from the patient for the publication of the present case report. Abbreviations CGM continuous glucose monitor SMBG self monitoring blood glucose Declarations Ethical considerations Informed consent was obtained from the patient for the publication of the present case report. Declaration of interest No potential conflict of interest was reported by the author. Data availability statement The data generated and analyzed in the presented study are available from the corresponding author on request. References 1. Langendam M, Luijf YM, Hooft L, Devries JH, Mudde AH, Scholten RJ. Continuous glucose monitoring systems for type 1 diabetes mellitus. Cochrane Database Syst Rev. 2012 ;1(1):CD008101. 2. Lundemose SB, Laugesen C, Ranjan AG, Nørgaard K. Factory-Calibrated Continuous Glucose Monitoring Systems in Type 1 Diabetes: Accuracy during In-Clinic Exercise and Home Use. Sensors (Basel). 2023 ;23(22):9256. 3. Berg AS, Crews CD, Adin C, Alfonso-Castro A, Hill SB, Mott J, Gilor C. Assessment of the FreeStyle Libre 2 interstitial glucose monitor in hypo- and euglycemic cats. J Vet Intern Med. 2023 ;37(5):1703-1709. 4. Yeoh E, Png D, Khoo J, Chee YJ, Sharda P, Low S, Lim SC, Subramaniam T. A head-to-head comparison between Guardian Connect and FreeStyle Libre systems and an evaluation of user acceptability of sensors in patients with type 1 diabetes. Diabetes Metab Res Rev. 2022 ;38(7):e3560. 5. Golla KK, Gupta Y, Goyal A, Kalaivani M, Kachhawa G, Kulshrestha V, Sharma AK, Meena J, Bharti J, Sharma JB, Dadhwal V, Malhotra N, Bhatla N, Tandon N. Comparison of Accuracy of Freestyle Libre Pro and Medtronic iPro2 Continuous Glucose Monitoring Systems in Pregnancy. Diabetes Technol Ther. 2023 ;25(8):538-542. 6. Ólafsdóttir AF, Andelin M, Saeed A, Sofizadeh S, Hamoodi H, Jansson PA, Lind M. Performance of Dexcom G5 and FreeStyle Libre sensors tested simultaneously in people with type 1 or 2 diabetes and advanced chronic kidney disease. World J Clin Cases. 2022 ;10(22):7794-7807. 7. Fava S. Role of postprandial hyperglycemia in cardiovascular disease. Expert Rev Cardiovasc Ther. 2008 ;6(6):859-72. 8. Malin SK, Finnegan S, Fealy CE, Filion J, Rocco MB, Kirwan JP. β-Cell dysfunction is associated with metabolic syndrome severity in adults. Metab Syndr Relat Disord. 2014 ;12(2):79-85. 9. Knutsson A, Karlsson B, Ornkloo K, Landström U, Lennernäs M, Eriksson K. Postprandial responses of glucose, insulin and triglycerides: influence of the timing of meal intake during night work. Nutr Health. 2002;16(2):133-141. 10. Sadiya A, Jakapure V, Kumar V. Ethnic Variability in Glucose and Insulin Response to Rice Among Healthy Overweight Adults: A Randomized Cross-Over Study. Diabetes Metab Syndr Obes. 2023 ;16:993-1002. 11. Law M, Lee YT, Vien S, Luhovyy BL, Anderson GH. The effect of dairy products consumed with high glycemic carbohydrate on subjective appetite, food intake, and postprandial glycemia in older adults. Appl Physiol Nutr Metab. 2017 ;42(11):1210-1216. 12. Taniguchi A, Yamanaka-Okumura H, Nishida Y, Yamamoto H, Taketani Y, Takeda E. Natto and viscous vegetables in a Japanese style meal suppress postprandial glucose and insulin responses. Asia Pac J Clin Nutr. 2008;17(4):663-668. Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 3 posted You are reading this latest preprint version Show more versions 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. 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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-3893915","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":271423535,"identity":"005ffb1c-aac5-4773-8300-109a7a82d6c3","order_by":0,"name":"Eiji Kutoh","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0ElEQVRIiWNgGAWjYDACZoaEgw1Amh/ESSggXosBgyRIX4IBkRYxgrQYHAAxidHCz87w8ODMtj9yxudXJ354YMAgzy92AL8WyWagwza2GRib3Xi7WQLoMMOZsxPwazE4DNTysM0gcduNsxtAWhIMbhPQYg/TsnnG2c0/iNJiwAxxWOIG/t5txNkiAbJlxjljY4kbvNssEgwkCPuFv/9M8seeMjk5/v6zm2/+qLCR55cmoIWBgQeqQgJMSxBSDgLsB6D2HSBG9SgYBaNgFIxEAAB13kgVSoy6GQAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0009-0009-3873-9568","institution":"Biomedical Center","correspondingAuthor":true,"prefix":"","firstName":"Eiji","middleName":"","lastName":"Kutoh","suffix":""}],"badges":[],"createdAt":"2024-01-24 11:28:52","currentVersionCode":3,"declarations":{"humanSubjects":true,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":true,"humanSubjectConsent":true,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":true,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-3893915/v3","doiUrl":"https://doi.org/10.21203/rs.3.rs-3893915/v3","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":51016180,"identity":"9b020756-0c86-414f-abdc-015b7e0835a2","added_by":"auto","created_at":"2024-02-12 19:00:07","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":16810,"visible":true,"origin":"","legend":"\u003cp\u003eWith 3 bananas (estimated carbohydrate 45g, started at 7:55), the glucose peak was 162 mg/dl at 9:02 (FreeStyle Libre) and 124 mg/dl at 9:03 (G6). SMBG noted 120 mg/dl at 9:04. three bananas started at 7:55\u003c/p\u003e","description":"","filename":"Fig.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3893915/v3/3e6423d3967959497abf7b7e.jpg"},{"id":51016552,"identity":"0ddae465-c1b8-4da9-9f8d-f50dabbd3509","added_by":"auto","created_at":"2024-02-12 19:08:07","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":16045,"visible":true,"origin":"","legend":"\u003cp\u003eWith tofu and natto (fermented beans, estimated carbohydrate 30 g, started at 12:30), the glucose peak was 103 mg/dl at 13:49 (FreeStyle Libre) and 100 mg/dl at 14:13 (G6). SMBG showed 102 mg/dl at 13:55. tofu and natto started at 12:00\u003c/p\u003e","description":"","filename":"Fig.2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3893915/v3/601d4052dc8607dc9ddb9f57.jpg"},{"id":51016551,"identity":"8efe0583-944d-4405-b390-77a883e32245","added_by":"auto","created_at":"2024-02-12 19:08:07","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":17828,"visible":true,"origin":"","legend":"\u003cp\u003eWith natural yogurt (non-sweetened, 300ml), cheese (4 pieces), and chocolate (estimated carbohydrate 45 g, started at 12:30), the glucose peak was 126 mg/dl at 13:05 (FreeStyle Libre) and 112 mg/dl at 13:04 (G6). SMBG measured 107 mg/dl at 13:08. yogurt, cheese and chocolate started at 12:00\u003c/p\u003e","description":"","filename":"Fig.3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3893915/v3/956270f40ba927354a309d69.jpg"},{"id":51016183,"identity":"634906be-4aa6-409f-b339-effc82e7c1b6","added_by":"auto","created_at":"2024-02-12 19:00:07","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":18620,"visible":true,"origin":"","legend":"\u003cp\u003eWith a very big portion of assorted sushi (estimated carbohydrate 200g started at 18:15), the glucose peak was 198 mg/dl at 19:07 (FreeStyle Libre) and 171 mg/dl at 19:09 (G6). SMBG indicated 168 mg/dl at 19:12. big portion of assorted sushi started at 18:15\u003c/p\u003e","description":"","filename":"Fig.4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3893915/v3/c7c2f7a8967025b2d520a396.jpg"},{"id":51016185,"identity":"1d2a5a08-05db-47cc-b0ba-aa74b40fd115","added_by":"auto","created_at":"2024-02-12 19:00:07","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":18205,"visible":true,"origin":"","legend":"\u003cp\u003eWith a big portion of Chinese noodle (estimated carbohydrate 150 g, started at 21:30), the glucose peak was 184 mg/dl at 22:15 (FreeStyle Libre) and 159 mg/dl at 22:18 (G6). SMBG showed 151 mg/dl at 22:19. Chinese noodle started at 21:30\u003c/p\u003e","description":"","filename":"Fig.5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3893915/v3/0fa5fa1fe05e5bb83339d7a6.jpg"},{"id":51017619,"identity":"6a2ad293-eba8-4a02-b0a5-1358d103a6f3","added_by":"auto","created_at":"2024-02-12 19:16:08","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":295567,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3893915/v3/c11c6137-b11a-4e41-9ae3-4e1bba424866.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"Accuracy of Abott Freestyle Libre versus Dexcom G6 in a patient with pre-diabetes: a case report and review of literature","fulltext":[{"header":"Introduction","content":"\u003cp\u003eContinuous Glucose Monitoring (CGM) is an invaluable device for the ongoing assessment of interstitial fluid glucose levels, particularly for individuals undergoing insulin injections. Various CGM systems, utilizing diverse technologies, are currently available or in developmental stages. Comparative studies with self-monitoring blood glucose (SMBG) demonstrate that CGM not only reduces HbA1c but also diminishes the duration and frequency of hypoglycemic events (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Presently, two widely utilized systems, Abbott FreeStyle Libre (Abbott, Chicago, USA) and Dexcom G6 (Dexcom, San Diego, USA), have gained prominence worldwide. Notably, these systems eliminate the need for calibration with SMBG (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eA distinguishing feature of FreeStyle Libre, classified as a flash glucose monitoring (FGM) or intermittently scanned continuous glucose monitoring (isCGM) system, is its ability to continuously measure interstitial fluid glucose levels within the sensor at 15-minute intervals for up to 8 hours. Unlike many other CGM systems, including G6, FreeStyle Libre stores all data internally in the sensor (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). While the original FreeStyle Libre has been discontinued in some countries, it remains available in others, such as Japan. The newer versions, FreeStyle Libre 2 or 3, are recommended, offering enhancements like alarms for high or low glucose levels and more frequent glucose measurements (every 1 minute). Despite these updates, the fundamental technology remains consistent (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Several comparative reports evaluating glucose trends between FreeStyle Libre (original and versions 2) and other CGMs, including G6, in various specific circumstances suggest that FreeStyle Libre is less accurate under certain conditions (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTo date, there has been no comprehensive investigation involving the simultaneous use and comparison of two different CGM systems in an individual with pre-diabetes subjected to diverse dietary conditions. Prediabetes is characterized by blood glucose levels exceeding the normal range but not reaching the threshold for a diagnosis of type 2 diabetes (T2DM). The initial anomaly in glucose metabolism often manifests as an elevation in postprandial glucose levels due to diminished first-phase insulin secretion. Over time, a progressive decline in beta-cell function contributes to an increase in fasting glucose levels (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Patients with pre-diabetes frequently present as asymptomatic and may not undergo routine examinations. Halting the progression to overt T2DM necessitates the identification of populations at risk for prediabetes, coupled with encouragement for lifestyle modifications, including dietary changes and regular exercise. In such instances, CGM emerges as a highly beneficial method for continuous monitoring of blood glucose levels.\u003c/p\u003e \u003cp\u003eIn this study, CGM data were collected from a single patient diagnosed with prediabetes, characterized by elevated postprandial glucose levels alongside normal fasting blood glucose (FBG) and HbA1c. The participant concurrently wore both FreeStyle Libre and Dexcom G6 systems, allowing for the simultaneous measurement of glucose levels. The investigation involved monitoring glucose responses following the consumption of various traditional and modern Japanese diets.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eThe patient under scrutiny in this report is a 58-year-old male who has exhibited elevated postprandial glucose levels for the past decade. Despite maintaining normal fasting blood glucose and HbA1c levels (ranging from 87\u0026ndash;102 mg/dl and 5.4\u0026ndash;5.8%, respectively), his post-meal glucose levels vary (ranging from 130\u0026ndash;184 mg/dl) depending on dietary choices. One healthcare professional diagnosed him with \"pre-diabetes.\" The patient does not have any other clinically significant disorders and is not currently on any medication. His physical attributes include a height of 179 cm and a weight of 75 kg.\u003c/p\u003e \u003cp\u003eTo monitor blood glucose levels, the patient had been utilizing FreeStyle Libre and SMBG devices, such as Medisafe Fit Kit (Termo, Tokyo, Japan) or OneTouch Ultra Vue (LifeScan Japan, Tokyo, Japan). However, discrepancies in the data, particularly after meals, have been observed between these devices. To assess the accuracy and reliability of FreeStyle Libre data, the patient opted to simultaneously wear FreeStyle Libre (on the left upper arm) and G6 (on the right lower abdomen). This dual monitoring approach was employed to compare the data gathered after consuming various daily traditional and modern Japanese diets. As a control measure, intermittent SMBG tests were conducted to validate the data acquired from these two distinct CGMs.\u003c/p\u003e \u003cp\u003eThe FreeStyle Libre CGM has a lifespan of 14 days, whereas the Dexcom G6 CGM is designed for a duration of 10 days. It is empirically recognized within the medical community that the data recorded at the commencement and conclusion of these monitoring periods tends to be less stable. Consequently, in this report, data from day 2 through day 9 following initiation were selectively analyzed. Throughout this period, the individual maintained a calm state and refrained from engaging in excessive physical exercise after meals.\u003c/p\u003e \u003cp\u003eThe following the details of the CGM apparatus and data.\u003c/p\u003e \u003cp\u003eG6 receiver info: SN PG13705811\u003c/p\u003e \u003cp\u003eTransmitter SN 8PE5MM\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePN 9500-91\u003c/h2\u003e \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e \u003ch2\u003eLOT 5324787\u003c/h2\u003e \u003cp\u003eFreeStyle Libre reader SN JCGX052-T0265\u003c/p\u003e \u003cp\u003eLibre sensor 0m000UJLL AO\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e: With 3 bananas (estimated carbohydrate 45g, started at 7:55), the glucose peak was 162 mg/dl at 9:02 (FreeStyle Libre) and 124 mg/dl at 9:03 (G6). SMBG noted 120 mg/dl at 9:04.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e: With tofu and natto (fermented beans, estimated carbohydrate 30 g, started at 12:30), the glucose peak was 103 mg/dl at 13:49 (FreeStyle Libre) and 100 mg/dl at 14:13 (G6). SMBG showed 102 mg/dl at 13:55.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e: With natural yogurt (non-sweetened, 300ml), cheese (4 pieces), and chocolate (estimated carbohydrate 45 g, started at 12:30), the glucose peak was 126 mg/dl at 13:05 (FreeStyle Libre) and 112 mg/dl at 13:04 (G6). SMBG measured 107 mg/dl at 13:08.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e: With a very big portion of assorted sushi (estimated carbohydrate 200g started at 18:15), the glucose peak was 198 mg/dl at 19:07 (FreeStyle Libre) and 171 mg/dl at 19:09 (G6). SMBG indicated 168 mg/dl at 19:12.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e: With a big portion of Chinese noodle (estimated carbohydrate 150 g, started at 21:30), the glucose peak was 184 mg/dl at 22:15 (FreeStyle Libre) and 159 mg/dl at 22:18 (G6). SMBG showed 151 mg/dl at 22:19.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo validate the aforementioned results, a second trial using new sensors and similar diets was conducted, yielding nearly identical outcomes (results not shown).\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Discussions","content":"\u003cp\u003ePostprandial hyperglycemia not only elevates the relative risk for developing type 2 diabetes (T2DM) but also heightens the likelihood of cardiovascular complications, such as angina, myocardial infarction, or strokes (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). The mechanism by which postprandial hyperglycemia contributes to cardiovascular issues involves vascular oxidative stress, endothelial dysfunction, and an inflammatory response (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Consequently, it becomes crucial to identify individuals with elevated postprandial glucose levels and implement appropriate interventions. The primary objective of this study was to evaluate the accuracy of the two most widely used CGMs, Abbott FreeStyle Libre and Dexcom G6, in an individual with pre-diabetes characterized by postprandial hyperglycemia. This investigation was prompted by the subject's suspicion regarding the accuracy of FreeStyle Libre, stemming from observed disparities in glucose values compared to SMBG.\u003c/p\u003e \u003cp\u003eThis report demonstrates that, following the consumption of carbohydrate-rich diets (typically exceeding 40-50g), FreeStyle Libre consistently yielded higher and inaccurate glucose levels compared to reference SMBG data, while G6 provided more reliable glucose values (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Conversely, pre-meal glucose levels exhibited comparability and accuracy in both devices (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). It is imperative for FreeStyle Libre users to exercise caution and validate glucose values with SMBG, particularly in instances involving insulin injection. Furthermore, the applicability of these findings in patients with overt diabetes remains an open question and warrants exploration under various circumstances such as surgical operations, hemodialysis, exercise, or periods of relaxation. Further investigation is needed to ascertain whether similar results would be observed in these diverse scenarios.\u003c/p\u003e \u003cp\u003eWhile the accuracy of FreeStyle Libre, including both the original version and the newer version 2, remains a subject of debate among researchers, particularly when assessed by the Mean Absolute Relative Difference (MARD) (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e), its cost-effectiveness and certain favorable features make it a valuable tool in various scenarios. For instance, it can be particularly useful for comparing the impact of different diets on blood glucose levels, such as comparing the effects of bananas versus oranges or pizza versus pasta. Additionally, it can aid in assessing the peak time after consuming diverse meals.\u003c/p\u003e \u003cp\u003eTraditionally, postprandial glucose evaluation is empirically conducted at 2 hours after a meal. However, emerging research suggests that the peak postprandial glucose occurs around 60 minutes after eating (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). This time frame (around 60 minutes after meal) might serve as a more relevant predictor for the development of overt diabetes or cardiovascular disorders compared to the 2-hour mark. In the findings presented in this report, the peak glucose levels after meal ingestion were also approximately 60 minutes after ingestion (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). CGMs may be valuable in comparing the time taken to reach peak glucose levels based on the diet consumed (pasta vs. rice vs. bread). This information can be crucial in determining the optimal timing for post-meal exercise.\u003c/p\u003e \u003cp\u003eYogurt and cheese together with chocolate exhibited minimal glucose spikes in both devices though certain carbohydrates were ingested (Tables\u0026nbsp;3). This aligns with prior research indicating that dairy products can mitigate glucose excursions after a meal (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). Tofu and natto, both common Japanese foods derived from fermented soybeans, have been associated with potential protective effects against type 2 diabetes (T2DM) and the suppression of post-meal glucose spikes (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). In this study, little glucose spikes, if any, were noted with the consumption of tofu and natto (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Notably, low-carbohydrate diets are recognized as an effective strategy for controlling post-meal glucose elevation. However, one common challenge with such diets is the potential dissatisfaction of satiety. Remarkably, certain diets utilized in this study, such as tofu, natto, yogurt, cheese, and chocolate, not only exhibited minimal glucose spikes (results not shown as Figure or Table) but also provided a satisfactory level of satiety.\u003c/p\u003e \u003cp\u003eIn order to corroborate the findings of this study, it is imperative to conduct randomized, controlled dietary intervention trials encompassing diverse diets and a sufficiently large number of subjects. Such trials would shed light on the role of postprandial glycemia. Equally important is the exploration of the time course of postprandial glycemia to gain a comprehensive understanding of its potential impact.\u003c/p\u003e"},{"header":"Conclusion and recommendation","content":"\u003cp\u003eFreeStyle Libre consistently yielded higher and inaccurate postprandial glucose values, while Dexcom G6 demonstrated greater reliability following the ingestion of specific carbohydrate amounts in a person with pre-diabetes. Despite these discrepancies, FreeStyle Libre remains a useful tool for tracking trends in glucose changes. However, for added safety and result verification, occasional confirmation with Self-Monitoring of Blood Glucose (SMBG) is recommended.\u003c/p\u003e"},{"header":"Ethical considerations","content":"\u003cp\u003e \u003cstrong\u003eInformed consent\u003c/strong\u003e \u003cp\u003e was obtained from the patient for the publication of the present case report.\u003c/p\u003e \u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCGM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econtinuous glucose monitor\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSMBG\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eself monitoring blood glucose\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003ch3\u003eEthical considerations\u003c/h3\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from the patient for the publication of the present case report.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\n\u003ch3\u003eDeclaration of interest\u003c/h3\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNo potential conflict of interest was reported by the author.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ch3\u003eData availability statement\u003c/h3\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe data generated and analyzed in the presented study are available from the corresponding author on request.\u003c/p\u003e"},{"header":"References","content":"\u003cp\u003e1. Langendam M, Luijf YM, Hooft L, Devries JH, Mudde AH, Scholten RJ. Continuous glucose monitoring systems for type 1 diabetes mellitus. Cochrane Database Syst Rev. 2012 ;1(1):CD008101.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;2. Lundemose SB, Laugesen C, Ranjan AG, N\u0026oslash;rgaard K. Factory-Calibrated Continuous Glucose Monitoring Systems in Type 1 Diabetes: Accuracy during In-Clinic Exercise and Home Use. Sensors (Basel). 2023 ;23(22):9256.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;3. Berg AS, Crews CD, Adin C, Alfonso-Castro A, Hill SB, Mott J, Gilor C. Assessment of the FreeStyle Libre 2 interstitial glucose monitor in hypo- and euglycemic cats. J Vet Intern Med. 2023 ;37(5):1703-1709.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;4. Yeoh E, Png D, Khoo J, Chee YJ, Sharda P, Low S, Lim SC, Subramaniam T. A head-to-head comparison between Guardian Connect and FreeStyle Libre systems and an evaluation of user acceptability of sensors in patients with type 1 diabetes. Diabetes Metab Res Rev. 2022 ;38(7):e3560.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;5. Golla KK, Gupta Y, Goyal A, Kalaivani M, Kachhawa G, Kulshrestha V, Sharma AK, Meena J, Bharti J, Sharma JB, Dadhwal V, Malhotra N, Bhatla N, Tandon N. Comparison of Accuracy of Freestyle Libre Pro and Medtronic iPro2 Continuous Glucose Monitoring Systems in Pregnancy. Diabetes Technol Ther. 2023 ;25(8):538-542.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;6. \u0026Oacute;lafsd\u0026oacute;ttir AF, Andelin M, Saeed A, Sofizadeh S, Hamoodi H, Jansson PA, Lind M. Performance of Dexcom G5 and FreeStyle Libre sensors tested simultaneously in people with type 1 or 2 diabetes and advanced chronic kidney disease. World J Clin Cases. 2022 ;10(22):7794-7807.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;7. Fava S. Role of postprandial hyperglycemia in cardiovascular disease. Expert Rev Cardiovasc Ther. 2008 ;6(6):859-72.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;8. Malin SK, Finnegan S, Fealy CE, Filion J, Rocco MB, Kirwan JP. \u0026beta;-Cell dysfunction is associated with metabolic syndrome severity in adults. Metab Syndr Relat Disord. 2014 ;12(2):79-85.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;9. Knutsson A, Karlsson B, Ornkloo K, Landstr\u0026ouml;m U, Lennern\u0026auml;s M, Eriksson K. Postprandial responses of glucose, insulin and triglycerides: influence of the timing of meal intake during night work. Nutr Health. 2002;16(2):133-141.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;10. Sadiya A, Jakapure V, Kumar V. Ethnic Variability in Glucose and Insulin Response to Rice Among Healthy Overweight Adults: A Randomized Cross-Over Study. Diabetes Metab Syndr Obes. 2023 ;16:993-1002.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;11. Law M, Lee YT, Vien S, Luhovyy BL, Anderson GH. The effect of dairy products consumed with high glycemic carbohydrate on subjective appetite, food intake, and postprandial glycemia in older adults. Appl Physiol Nutr Metab. 2017 ;42(11):1210-1216.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;12. Taniguchi A, Yamanaka-Okumura H, Nishida Y, Yamamoto H, Taketani Y, Takeda E. Natto and viscous vegetables in a Japanese style meal suppress postprandial glucose and insulin responses. Asia Pac J Clin Nutr. 2008;17(4):663-668.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Biomedical Center","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":"pre-diabetes, postprandial hyperglycemia, CGM, FreeStyle Libre, G6","lastPublishedDoi":"10.21203/rs.3.rs-3893915/v3","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3893915/v3","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAbbott FreeStyle Libre and Dexcom G6 represent widely employed continuous glucose monitoring (CGM) systems globally. However, their precision remains unexplored concerning postprandial glucose levels in individuals with pre-diabetes following the consumption of diverse dietary regimens.\u003c/p\u003e \u003cp\u003eA 58-year-old Japanese man diagnosed with pre-diabetes (postprandial hyperglycemia) underwent simultaneous monitoring using Abbott FreeStyle Libre and Dexcom G6 following the consumption of diverse diets. In the pre-meal state, both systems exhibited comparable and reliable values (around 80\u0026ndash;100 mg/dl). However, around 60 minutes following meals containing specific amounts of carbohydrates (approximately above 50 g), FreeStyle Libre demonstrated a more pronounced acceleration in the increase and peak glucose values compared to G6. These discrepancies were further validated through self-monitoring of blood glucose (SMBG) measurements, confirming the less accurate performance of FreeStyle Libre under these conditions. To this end, it appears that fermented products (beans, yogurt, cheese) could suppress postprandial glucose spikes.\u003c/p\u003e \u003cp\u003eThe study results suggest that, when compared to G6, FreeStyle Libre yielded elevated glucose values and exhibited reduced accuracy in measuring postprandial glucose levels following the ingestion of a specific amount of carbohydrates in a patient with pre-diabetes.\u003c/p\u003e","manuscriptTitle":"Accuracy of Abott Freestyle Libre versus Dexcom G6 in a patient with pre-diabetes: a case report and review of literature","msid":"","msnumber":"","nonDraftVersions":[{"code":3,"date":"2024-02-12 19:00:03","doi":"10.21203/rs.3.rs-3893915/v3","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}},{"code":2,"date":"2024-02-06 20:00:47","doi":"10.21203/rs.3.rs-3893915/v2","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}},{"code":1,"date":"2024-01-25 19:32:09","doi":"10.21203/rs.3.rs-3893915/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":"7e193f75-3853-44c5-89bb-618461874bf5","owner":[],"postedDate":"February 12th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-01-25T19:32:09+00:00","versionOfRecord":[],"versionCreatedAt":"2024-02-12 19:00:03","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v3","identity":"rs-3893915","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3893915","identity":"rs-3893915","version":["v3"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}