Lower serum leptin levels in female students of the nutritional sciences with eating disorders

Evidence has accumulated that in both acutely ill and recovered patients with either anorexia or bulimia nervosa circulating leptin levels (LL) are lower than in controls matched for body mass index (BMI; kg/m(2)). It is unknown if these lower leptin levels represent a state or trait marker.

We aimed to confirm the lowered leptin levels in eating disordered females and to identify underlying mechanisms.

We screened 181 female students of the nutritional sciences for eating disorders with the respective module of the M-Composite International Diagnostic Interview and the Cognitive Restraint scale of the Three Factor Eating Questionnaire. The physical assessment included determinations of BMI, body composition and LL. Each case fulfilling lifetime DSM-IV criteria for an eating disorder was BMI matched to two controls. We used a multivariate mixed regression model to evaluate if the observed difference in lg(10)-leptin level between cases and controls is actually due to the influence of restrained eating and/or previous weight loss after adjustment for BMI and percent body fat.

In accordance with our hypothesis the 32 (17.7 %) cases had a lower serum lg(10)-leptin level than the 64 BMI matched controls (one-sided p < 0.001). We were not able to detect an influence of restrained eating or previous weight loss.

We confirm that females with a lifetime history of an eating disorder have lower LL. We were not able to identify an underlying mechanism. Similar to most previous studies we found a high rate of eating disorders among female students of nutritional sciences.