Assessment of glucose effectiveness from short IVGTT in individuals with different degrees of glucose tolerance

• Published in: Acta diabetologica Vol. 55; no. 10; pp. 1011 - 1018
• Main Authors: Morettini, Micaela, Di Nardo, Francesco, Burattini, Laura, Fioretti, Sandro, Göbl, Christian, Kautzky-Willer, Alexandra, Pacini, Giovanni, Tura, Andrea
• Format: Journal Article
• Language: English
• Published: Milan Springer Milan 01.10.2018; Springer Nature B.V
• Subjects: Adult; Aged; Blood Glucose - metabolism; Diabetes; Diabetes mellitus; Diabetes mellitus (insulin dependent); Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2 - metabolism; Female; Glucose; Glucose tolerance; Glucose Tolerance Test; Humans; Insulin; Insulin - metabolism; Insulin Resistance; Internal Medicine; Intravenous administration; Male; Mathematical models; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; Original Article; Regression Analysis; Young Adult; One hour intravenous glucose tolerance test; Non-insulin-mediated glucose disappearance; Basal insulin effect; Empirical index; Mathematical model
• ISSN: 0940-5429; 1432-5233; 1432-5233
• DOI: 10.1007/s00592-018-1182-3

Aims Minimal model analysis of intravenous glucose tolerance test (IVGTT) data represents the reference method to assess insulin sensitivity ( S I ) and glucose effectiveness ( S G ) that quantify the insulin-dependent and insulin-independent processes of glucose disappearance, respectively. However, test duration (3 h) and need for modeling expertise limit the applicability of this method. Aim of this study was providing a simple predictor of S G applicable to short test (1 h), as previously done with S I . Methods Three groups of subjects reflecting different glucose tolerance degrees underwent a 3 h IVGTT: subjects with normal glucose tolerance (NGT, n  = 164), with defective glucose regulation (DGR, n  = 191), and with type 2 diabetes (T2D, n  = 39). Minimal model analysis provided reference S G and its components at zero (GEZI) and basal (BIE) insulin. The simple predictor CS G (calculated S G ) was described by the formula CS G  =  α 0  +  α 1  ×  K G / G peak , being K G the glucose disappearance rate (between 10 and 50 min) and G peak the maximum of the glucose curve during the test; α 0 and α 1 coefficients were provided by linear regression analysis. Results CS G and S G showed a markedly significant relationship in the whole dataset ( r  = 0.72, p  < 0.0001) and in the single groups ( r  = 0.70 in NGT, r  = 0.71 in DGR and r  = 0.70 in T2D, p  < 0.0001 for all); α 1  ×  K G / G peak was significantly related to GEZI ( r  ≥ 0.60). Conclusions The interest for insulin-independent glucose disappearance is increasing, due to the recent availability of SGLT2 pharmacological agents, lowering glycemic levels without requiring insulin action. This study proposes a reliable predictor of S G based on IVGTT lasting 1 h only, and not requiring mathematical modeling skills.