2467-P: Characterizing the Diurnal Variability of Insulin Sensitivity and Beta-Cell Responsivity in People with Type 2 Diabetes

Introduction and Objective: We have previously shown that the diurnal pattern of glucose tolerance following simple carbohydrate meals differ in people with or without type 2 diabetes (T2D). This study aimed to further characterize the inter-individual variability of insulin sensitivity (SI), beta cell responsivity (Φ) and disposition index (DI) in people with T2D. Methods: Nineteen subjects with T2D (Age=61±10 y; BMI=32±5 kg/m2; 7F) were studied with identical mixed meals (8 kcal/kg/meal;75 g carbohydrate) at breakfast, lunch, and dinner on 3 consecutive days in a randomized latin square design. Glucose and C-peptide minimal models were used to estimate SI, Φ and DI. We identified the maximum SI, Φ and DI in each individual and used Z-test to classify the remaining as high as the maximum (H) or significantly lower (L). Based on these classifications, each individual exhibited one of the following seven patterns across breakfast, lunch, and dinner: HHH, HHL, HLH, HLL, LHH, LHL, or LLH. Results: The most frequently observed patterns for SI, Φ and DI were LHL (7/19, 37%), HLL (7/19, 37%) and HHL (6/19, 32%), respectively (Fig.1). Conclusion: We described the heterogeneity of SI, Φ and DI daily patterns in T2D. Results show that, in most individuals with T2D, DI declines during the day. Perhaps changing meal type to complex carbohydrate or adjusting the exercise regimen could help sustaining glucose tolerance though the day. Disclosure J. Bonet: None. C. Dalla Man: Other - Webinar provider; Ended; Sanofi. Other - Joint research project; Current; Sanofi-Aventis Deutschland GmbH. B. Gran: None. A. Basu: Research Support; Current; Dexcom, Inc. M. Schiavon: Research Support; Current; Sanofi. R. Basu: None. Funding MUR PRIN 2022 PNRR (P2022XSFA7), NIH (R01 DK 029953)