313-OR: Diurnal Pattern of Meal Tolerance in Type 2 Diabetes

The existence of a diurnal pattern of post prandial glucose tolerance is relevant for management of patients with type 2 diabetes (T2D). We studied 10 healthy (4M) and 9 T2D (6M) subjects matched for age (56±3 vs. 58±3 yrs) and BMI (29±2 vs. 32±2 kg/m2). OGTT was done in healthy subjects to rule out diabetes. Identical mixed meals (8 kcal/kg/meal; 75 gm carb) were ingested during breakfast (B), lunch (L), and dinner (D) at 0700, 1300, and 1900 h in randomized latin square order with one labeled test meal/day on 3 consecutive days. Physical activity was kept same. Postprandial glucose turnover was measured utilizing the triple tracer technique modified with all stable isotopes ([1-13C] Glucose, [2-13C] Glucose and [6, 6-2H2] Glucose). Results shown in Fig 1. Fasting and post-meal glucose were higher while fasting and post-meal insulin and C-peptide concentrations lower in T2D for all three meals compared to healthy. Although meal glucose appearance did not differ between meals in either group, fasting endogenous glucose production (EGP) was higher, percent suppression of EGP lower in T2D and glucose disappearance (corrected for urine glucose loss) lower in T2D than healthy for all meals consumed. This data correlates with lower insulin sensitivity, B-cell responsivity to glucose and disposition index in T2D than healthy throughout the day. Our results suggest an emerging diurnal pattern to glucose tolerance and fluxes in humans, and that the pattern is different in T2D. Disclosure Y.R. Yadav: None. D. Romeres: None. F. Ruchi: None. S. Sawleh: None. R. Carter: None. A. Basu: Consultant; Spouse/Partner; GENFIT. Research Support; Spouse/Partner; AstraZeneca. R. Basu: Consultant; Self; GENFIT. Research Support; Self; AstraZeneca. Funding National Institutes of Health (R01DK029953 to R.B.), (R01DK085516 to A.B.), (DK059637, DK020593)