Plasma leptin in children: Relationship to puberty, gender, body composition, insulin sensitivity, and energy expenditure

Abstract Leptin has been demonstrated to reflect body fat mass (FM) in humans, but the regulation of leptin levels during childhood growth and development is poorly understood. We studied the relation between plasma leptin, fasting insulin, insulin sensitivity, and resting energy expenditure in 22 healthy prepubertal children and 27 adolescents. Body composition was assessed by the H 2 18 O-dilution principle, insulin sensitivity by a hyperinsulinemic (40 mU/m 2 /min)-euglycemic clamp, and energy expenditure by indirect calorimetry. Plasma leptin in prepubertal children (9.3 ± 2.0 ng/mL) was not different from that in pubertal adolescents (10.9 ± 2.2 ng/mL). Plasma leptin correlated with FM ( r = .77, P r = .60, P