Evaluation of insulin secretion through Intravenous Glucose Tolerance Test (IVGTT) in normoglycaemic lean individuals and in obese subjects with normoglycaemia or varying degrees of dysglycaemia

Evaluation of insulin secretion through Intravenous Glucose Tolerance Test (IVGTT) in normoglycaemic lean individuals and in obese subjects with normoglycaemia or varying degrees of dysglycaemia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Evaluation of insulin secretion through Intravenous Glucose Tolerance Test (IVGTT) in normoglycaemic lean individuals and in obese subjects with normoglycaemia or varying degrees of dysglycaemia Maria Chiara Pelle, Isabella Zaffina, Maria Resilde Natale, Vincenzo Trapanese, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9321152/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract We investigated the insulin secretion and glucose dynamics using intravenous glucose tolerance test (IVGTT) in obese subjects with varying metabolic profiles. We enrolled 68 subjects divided into 5 groups of obese individuals: normal glucose tolerance (Ob-NGT, n = 29), impaired fasting glucose (Ob-IFG, n = 2), impaired glucose tolerance (Ob-IGT, n = 16), Ob-IGT/IFG (n = 6), Ob-T2D (n = 6), and one control group of lean subjects with NGT (Lean-NGT, n = 9). Through IVGTT, we evaluated the acute insulin response (AIR) and insulin sensitivity was assessed using the calculated sensitivity index (CSi). β-cell function was determined using the Disposition Index (DI). Ob-T2D subjects exhibited a marked reduction in the first-phase insulin secretion (FPIS) compared with both Lean-NGT and Ob-NGT. In contrast, Ob-IGT, Ob-IFG and Ob-IFG/IGT subjects retained FPIS but demonstrated a pronounced enhancement of the second phase insulin secretion relative to both Ob-T2D and Ob-NGT. The secretion curves for Ob-NGT closely mirrored those of Ob-IGT in terms of overall pattern. We observed a significant difference between obese groups and Lean-NGT group in CSi (P = 0.000). Similarly, DI was markedly reduced in obese subjects compared with Lean-NGT and showed a progressive decline with worsening glucose tolerance within the obese cohort (P = 0.000). These findings highlight several alterations in insulin sensitivity and secretion in obese individuals relative to Lean-NGT controls. obesity diabetes metabolic disease IVGTT insulin secretion Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9321152","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":621652728,"identity":"0f085145-206f-4c53-9e30-7489be86dfe0","order_by":0,"name":"Maria Chiara Pelle","email":"","orcid":"","institution":"“Renato Dulbecco” University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Maria","middleName":"Chiara","lastName":"Pelle","suffix":""},{"id":621652731,"identity":"fec5ef6a-5a6b-4b06-a29b-db45481ea053","order_by":1,"name":"Isabella Zaffina","email":"","orcid":"","institution":"Internal Medicine Unit, San Francesco 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We enrolled 68 subjects divided into 5 groups of obese individuals: normal glucose tolerance (Ob-NGT, n\u0026thinsp;=\u0026thinsp;29), impaired fasting glucose (Ob-IFG, n\u0026thinsp;=\u0026thinsp;2), impaired glucose tolerance (Ob-IGT, n\u0026thinsp;=\u0026thinsp;16), Ob-IGT/IFG (n\u0026thinsp;=\u0026thinsp;6), Ob-T2D (n\u0026thinsp;=\u0026thinsp;6), and one control group of lean subjects with NGT (Lean-NGT, n\u0026thinsp;=\u0026thinsp;9). Through IVGTT, we evaluated the acute insulin response (AIR) and insulin sensitivity was assessed using the calculated sensitivity index (CSi). β-cell function was determined using the Disposition Index (DI). Ob-T2D subjects exhibited a marked reduction in the first-phase insulin secretion (FPIS) compared with both Lean-NGT and Ob-NGT. In contrast, Ob-IGT, Ob-IFG and Ob-IFG/IGT subjects retained FPIS but demonstrated a pronounced enhancement of the second phase insulin secretion relative to both Ob-T2D and Ob-NGT. The secretion curves for Ob-NGT closely mirrored those of Ob-IGT in terms of overall pattern. We observed a significant difference between obese groups and Lean-NGT group in CSi (P\u0026thinsp;=\u0026thinsp;0.000). Similarly, DI was markedly reduced in obese subjects compared with Lean-NGT and showed a progressive decline with worsening glucose tolerance within the obese cohort (P\u0026thinsp;=\u0026thinsp;0.000). 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