Comparison of fasting plasma leptin concentrations in healthy subjects with high and low plasma insulin

This study was initiated to evaluate the role of hyperinsulinemia in the re gulation of fasting plasma leptin. We measured plasma leptin and insulin co ncentrations in 404 healthy nondiabetic subjects. For analytical purposes, the population was divided into quartiles on the basis of the lowest (quart ile 1) and highest (quartile 4) plasma insulin response to oral glucose, an d fasting plasma leptin values in these 2 dichotomous groups were compared. The total plasma integrated insulin response was 4-fold greater in quartil e 4, associated with significantly higher (P <.001) fasting plasma leptin ( 12.60 +/- 0.85 v 8.53 +/- 0.56 ng/mL). Fasting plasma leptin concentrations remained significantly higher in the hyperinsulinemic quartile when compar isons were made after subdividing the population on the basis of gender, bo dy mass index (BMI), or waist to hip ratio (WHR). These results demonstrate that fasting plasma leptin concentrations are significantly higher in hype rinsulinemic individuals, and this difference is independent of either over all or central obesity. Copyright (C) 2000 by W.B. Saunders Company.