Net protein anabolic response is not altered during hyperaminoacidemic (hyperAA) clamp in men with Type 2 Diabetes (T2D)

Abstract

Reduced 24h net protein balance in hyperglycemic T2D was explained by less protein accretion during hyperinsulinemic euglycemic, isoaminoacidemic (isoAA) clamps. We tested whether protein anabolism would worsen with glycemia at 8.0 mM and AA at iso (fasting) or hyper (postprandial). Eight T2D men (57±2 y; BMI: 34±2; FPG: 8.4±0.6mM) underwent hyperinsulinemic (600 pM), hyperglycemic clamps with glucose and leucine kinetics measured at 2 steady-states: isoAA and hyperAA. Results are compared to 10 T2D and 10 lean nondiabetic men studied euglycemic, isoAA and 9 studied hyperglycemic, hyperAA.

In T2D 1) Leucine flux was higher (4.3±0.1 vs. 3.1±0.2 micromol/FFM.min) but net protein balance not different (0±.03 micromol/FFM.min) with isoAA when glycemia was at 8.0 vs. 5.5; net balance was less than in lean (0.25±0.02); however response to hyperAA was as in lean (0.9±.09) 2) endogenous glucose production was less suppressed (1.7±0.4 vs. 0.7±0.2mg/FFM.min) and glucose uptake higher (4.8±.6 vs. 3.6±0.3 mg/FFM.min) with glycemia at 8 vs. 5.5 and with hyperAA. 3) hyperAA did not lower glucose metabolic clearance rate (3.3±0.3 vs. 3.6±0.4 ml/FFM.min), as in lean (9.3±0.7 vs. 5.7±0.4). Thus, protein anabolic response to postprandial AA in T2D is not altered despite indication of insulin resistance of protein. (CIHR)