Determinants of plasma adiponectin levels in patients with anorexia nervosa examined before and after weight gain

Objective To examine the determinants of adiponectin levels (i) in 23 women with anorexia nervosa (mean BMI 15.0 +/- 1.2) and 43 healthy normal weight females (mean BMI 22.3 +/- 2.3; cross-sectional design) as well as (ii) after six and twelve weeks of weight gain in subgroups of 18 and 11 anorectic patients (mean weight gain 5.8kg; longitudinal design). Plasma adiponectin and leptin concentrations were measured and their relationships to body composition (fat mass by bioelectrical impedance analysis and anthropometrics), different hormones and metabolic parameters (insulin, ACTH, cortisol, glucose, FFA, lipid profile) were investigated. Results In anorectic patients, adiponectin levels were higher (+29 %) and leptin levels were lower (-75 %) than in control subjects. There was a high variance in adiponectin levels in patients ranging from 2.6 to 18nM. Combining patients and controls, an inverse linear correlation was observed between adiponectin levels and fat mass (r = -0.36, p < 0.05), while a positive exponential relation was found between leptin levels and fat mass (r = 0.82, p < 0.001). In anorectic patients, there were no significant correlations between adiponectin and hormonal or metabolic parameters. Weight gain resulted in increasing leptin (+0.17 +/- 0.12nM; p < 0.001) and a nonsignificant decrease in adiponectin concentrations (-1.12 +/- 2.51nM). Changes in leptin levels were mainly explained by a gain in fat mass (r = 0.85, p < 0.001). In contrast, changes in adiponectin levels were closely linked to initial adiponectin levels (r = -0.84, p < 0.001) but not to changes in fat mass or BMI. Conclusions Cross-sectionally serum adiponectin concentration followed a linear inverse function with fat mass when patients and controls were combined. Longitudinally gain in fat mass was not associated with changes in adiponectin levels suggesting other yet unidentified influences on adiponectin secretion in anorexia nervosa.