Objective: To evaluate serum leptin levels in anorectic women, menstruating women with low body mass indexes (BMI) and normally menstruating women with normal BMI.
Design: Prospective study.
Setting: University clinics.
Patient(s): Fourteen amenorrheic patients with anorexia nervosa (group A), 11 menstruating women with a BMI <18 kg/m(2) (group B), and 20 normal controls.
Main outcome measure(s): Determination of BMI, caloric intake, total fat mass, ovarian volume, and serum leptin, insulin-like growth factor I, FSH, LH, E(2), PRL, and TSH levels.
Intervention(s): None.
Result(s): Mean BMI and fat mass were similar in groups A and B and significantly higher in controls. Mean caloric intake was significantly lower in group A than in group B and controls. Median serum leptin levels were significantly lower in group A than in group B and controls, and significantly lower in group B than in controls. Median serum insulin-like growth factor I levels were significantly lower in group A than in group B and controls. Binary segmentation analysis of groups A and B showed that LH was the most relevant variable in differentiating the two groups, followed by leptin.
Conclusion(s): A threshold of leptin levels exist above which, even in the presence of low body mass indexes, the menstrual function is preserved.