Fasting plasma leptin level is a surrogate measure of insulin sensitivity

Context: Published studies indicate marked variability in plasma leptin levels among persons with similar body mass index (BMI). We tested the hypothesis that such variations in leptin levels reflect differences in insulin sensitivity. Subjects and Methods: Using euglycemic clamp, we assessed insulin sensitivity (ISI) in 57 nondiabetic adults (36 women, 21 men), whose BMI ranged from 20 to 78 kg/m2. We identified 38 age-matched subjects, stratified by fasting leptin (normal