Background: Adolescents with anorexia nervosa (AN) have low bone mineral density (BMD). Adipokines and insulin play an important role in bone metabolism in healthy individuals. However, their association with bone metabolism in AN is unknown.

Objective: To determine whether adipokines and insulin are independently associated with measures of BMD in adolescents with AN and controls.

Design/Methods: Levels of adiponectin and insulin, fasting and after oral glucose, were evaluated in 17 AN and 19 controls 12-18 yo, in whom hormonal parameters (growth hormone, IGF-I, cortisol, estradiol, leptin, ghrelin and peptide YY) had been previously determined. Body composition, bone mineral content (BMC) and BMD at the lumbar spine (LS), hip, femoral neck (FN) and total body (TB) were assessed by DXA. Two bone formation and bone resorption markers were examined.

Setting: General Clinical Research Center.

Results: Adiponectin differed between AN and controls after controlling for fat mass, and decreased in both following oral glucose (P = 0.02 and 0.07). On regression modeling, independent associations were observed of (i) BMI and adiponectin with LS bone mineral apparent density (BMAD) Z- scores (r² = 0.45), (ii) lean mass, peptide YY and ghrelin with hip Z-scores (r² = 0.55), (iii) adiponectin and lean mass with FN-BMAD Z-scores (r² = 0.34), and (iv) lean mass, PYY, GH and ghrelin with TB-BMC/height Z-scores (r² = 0.64), for the combined group. Adiponectin was also independently associated with BMD, and insulin with bone turnover markers in the groups considered separately.

Conclusions: Adiponectin contributes significantly to the variability of bone density, and insulin to bone turnover markers in adolescent girls.