Prognostic indicators of changes in bone density measures in adolescent girls with anorexia nervosa-II

Introduction: Adolescents with anorexia nervosa (AN) have low bone mineral density (BMD). Baseline predictors of temporal BMD changes (Delta BMD) in AN, including 1) gastrointestinal peptides regulating food intake and appetite that have been related to bone metabolism and 2) bone turnover markers, have not been well characterized. We hypothesized that baseline levels of nutritionally regulated hormones and of bone turnover markers would predict Delta BMD overall. Methods: In a prospective observational study, lumbar and whole-body BMD was measured at 0, 6, and 12 months in 34 AN girls aged 12-18 yr and 33 controls. Baseline body mass index, lean mass, nutritionally regulated hormones [IGF-I, cortisol, ghrelin, leptin, and peptide YY (PYY)], bone formation, and resorption markers were examined to determine nutritional and hormonal predictors of bone density changes. Results: In a regression model, baseline ghrelin and PYY predicted changes in spine bone measures; and baseline ghrelin, cortisol, and PYY predicted changes in whole-body bone measures independent of baseline nutritional status. Conclusions: Neuroendocrine gastrointestinal-derived peptides regulating food intake are independent predictors of changes in bone mass in AN.