SKELETAL MUSCLE INSULIN SENSITIVITY AND DURATION OF TYPE 2 DIABETES MELLITUS

Type 2 Diabetes Mellitus (T2DM) resolution following Roux-en Y gastric bypass (RYGB) surgery is reduced in patients with longer duration of T2DM and preliminary data suggest this may be mechanistically linked to lower pre-RYGB insulin sensitivity. Insulin sensitivity is reduced in T2DM. Skeletal muscle accounts for 60-80% of insulin mediated glucose disposal. PURPOSE: It was hypothesized that insulin sensitivity would be lowest in T2DM patients with long-duration (LD; [greater than or equal to] 8 y) compared to short-duration (SD; < 8 y). METHODS: Insulin sensitivity (Si) and the acute response to glucose (AIRg) were measured following an insulin modified intravenous glucose tolerance test (IVGTT) using Minimal Model analysis in T2DM patients (N = 14). RESULTS: There was a significant (p = 0.010) difference in Si between short and long T2DM duration (LD: 0.47 ± 0.7; SD: 1.94 ± 0.96 min/mU/ml) and a significant correlation between Si and duration of T2DM (r = -0.70; p = 0.010). There was a significant difference in AIRg between groups. There was a significant correlation between HbA1c (an index of glycemic control) and Si (r = -0.76; p = 0.002) but not between HbA1c and AIRg (r = -0.36; p = 0.204). CONCLUSIONS: Insulin sensitivity is lower in T2DM patients with longer duration of T2DM. Clinically poor glycemic control in long duration T2DM may be partially explained by reduced skeletal muscle insulin sensitivity