Is Fasting Leptin Associated With Insulin Resistance Among Nondiabetic I n d i v i d u a l s

dent of the effects of hyperinsulinemia and adiposity is an important unanswered question. We examined the relationship between the rate of insulin-mediated glucose uptake and serum leptin concentrations among nondiabetic men and women. RESEARCH DESIGN AND METHODS — A cross-sectional analysis was perf o rm e d among 49 young to middle-aged men and women who participated in the Miami Community Health Study. All participants had measures of insulin resistance (euglycemic-hyperinsulinemic clamp), postchallenge insulin levels, fasting serum leptin levels, and several measures of adiposity. R E S U LT S — The rate of insulin-mediated glucose uptake (M in milligrams per kilogram per minute) was significantly associated with leptin concentrations in both men (r = 20.83; P , 0.001) and women (r = 20.59; P , 0.001). M was also inversely related to percent body fat and to the 2-h insulin area under the curve (AUC). After covariate adjustment for sex, perc e n t body fat, and AUC, leptin remained a significant correlate of M (P = 0.04). C O N C L U S I O N S — C ro s s - s e c t i o n a l l y, leptin was significantly associated with insulin re s i stance in this nondiabetic sample of men and women. There may be a diff e rent physiological mechanism to explain the leptin/insulin resistance association apart from the insulin/adiposity link. Confirm a t o ry evidence awaits the results of clinical trials.