The role of leptin in human growth and puberty

Experimental animal studies demonstrate the effects of leptin on appetite, weight gain and metabolism. The biological effects of leptin in human adult s are still to be determined, but recent reports show that congenital lepti n deficiency leads to hyperphagia and excessive weight gain from early infa ncy as well as failure of pubertal onset in adolescence. Our recently repor ted data from two longitudinal cohorts suggest a role for leptin in the nor mal regulation of childhood weight gain, maturation and the development of secondary sexual features and body composition. Low leptin levels in cord b lood closely reflected decreased adiposity at birth and strongly predicted high rates of weight gain in infancy and catch-up growth. In adolescents, l eptin levels rose gradually with age prior to puberty, suggesting that a th reshold effect may trigger puberty. Tn girls, low leptin levels at the star t of puberty predicted large gains in the percentage of fat mass, perhaps s uggesting a role in the preparation for childbearing.