Relationship of leptin to bone mineralization in children and adolescents.

Serum leptin concentrations and bone mass are concordant in several respects. Obesity is associated with increased serum leptin concentrations and bone mineral, whereas undernutrition reduces serum leptin concentrations and bone mineral. Furthermore, both bone mineral and serum leptin concentrations increase at the initiation of puberty. However, there is a lack of empirical evidence of an independent association of serum leptin concentrations and bone mineral in youth. Thus, we used hierarchical regression to determine whether serum leptin concentrations were related to bone mineral in boys (n = 28) and girls (n = 31). Bone mineral content, density, and apparent density of the total body and body regions were measured by dual-energy x-ray absorptiometry and statistically adjusted for chronological age, fat mass, bone-free fat-free mass, and serum IGF-I and estradiol concentrations. Sequential addition of serum log((10)) leptin concentrations to the block of body size variables and the block of hormone variables did not increase R(2) for any of the total or regional bone mineral content, bone mineral density, and bone mineral apparent density variables. We conclude that serum leptin concentrations do not add to the prediction of bone mineral in youth after accounting for age, fat mass, bone-free fat-free mass, and serum IGF-I and estradiol concentrations.