Homeostasis model assessment as a clinical index of insulin resistance in type 2 diabetic patients treated with sulfonylureas

OBJECTIVE - To investigate whether the insulin resistance index (IR) assess ed by homeostasis model assessment (HOMA) is associated with the insulin re sistance index assessed by euglycemic-hyperinsulinemic clamp (clamp IR) in type 2 diabetic patients who received sulfonylureas (SUs), as well as in th ose treated by diet alone. RESEARCH DESIGN AND METHODS - Retrospectively the association between HOMA IR and clamp IR was analyzed in 80 type 2 diabetic subjects (53 subjects tr eated with SUs and 27 subjects treated with diet alone). The 80 subjects, s elected because they had not received insulin therapy were among 111 diabet ic participants in a clamp study for evaluation of insulin resistance from May 1993 to December 1997 in Osaka City University Hospital. RESULTS - The HOMA IR showed a hyperbolic relationship with clamp IR The lo g-transformed HOMA IR tall subjects, r = -0.725, P < 0.0001; SU group, r = -0.727, P < 0.0001; diet group, r = -0.747, P < 0.0001) correlated more str ongly with clamp IR than did HOMA IR per se tall subjects, r= -0.594, P< 0. 0001; SU group, r = -0.640, P < 0.0001; diet group, r = - 0.632, P = 0.0004 ). The univariate regression line between log-transformed HOMA IR and clamp IR in the SU group did not differ from that in the diet group (slope, -6.8 66 vs. -5.120, P > 0.05; intercept, 6.566 vs. 5.478, P > 0.05). Stepwise mu ltiple regression analyses demonstrated that the log-transformed HOMA IR wa s the strongest independent contributor to clamp IR (R-2 = 0.640, P < 0.000 1). CONCLUSIONS - The HOMA LR strongly correlated with the clamp IR in type 2 d iabetic patients treated viith SUs as well as in those treated with diet al one.