Role of leptin during childhood growth and development

Leptin, the product of the ob/ob gene in rodents, regulates energy balance and fertility. Two genetic models, the ob/ob mouse (deletion of leptin prot ein) and the db/db mouse (deletion of leptin receptor) have markedly augmen ted research in obesity. Human obesity is more closely linked to leptin res istance than to the absence of leptin. Serum leptin concentrations reflect the size of the subcutaneous fat depot better than total fat mass or abdomi nal visceral fat. At the initiation of puberty there is a divergence in cir culating leptin concentrations between boys and girls, in boys, leptin conc entrations increase and then markedly decrease to prepubertal concentration levels. In girls there are only increasing concentrations. The authors bel ieve these patterns are relevant to the markedly different alterations in t he regional distribution of body fat that occurs in boys and girls at puber ty.