Reduced plasma leptin concentrations in bulimia nervosa

Area of Science:

• Neuroscience
• Endocrinology
• Psychiatry

Background:

• Leptin, a protein inhibiting food intake, is linked to obesity and anorexia nervosa (AN).
• Previous research indicated unaltered leptin levels in bulimia nervosa (BN).

Purpose of the Study:

• To investigate fasting plasma leptin levels in women with BN.
• To determine if leptin levels correlate with body mass index (BMI), weight, or concurrent AN.
• To explore potential relationships between leptin, cortisol, and prolactin levels.

Main Methods:

• Radioimmunoassay measurement of fasting plasma leptin in 53 women (37 with BN, 16 controls).
• BN group stratified by concurrent AN diagnosis and BMI.
• Analysis of correlations between leptin, BMI, weight, cortisol, and prolactin responses.

Main Results:

• Plasma leptin levels significantly correlated with BMI, weight, and %ABW in the total group.
• BN subjects exhibited significantly lower leptin levels than normal controls (NCs), even after controlling for BMI and weight.
• No significant difference in leptin between BN with AN and BN without AN; however, leptin was decreased in BN without AN compared to NCs despite comparable BMI.

Conclusions:

• This is the first report of decreased plasma leptin levels in BN.
• Reduced leptin concentration in BN is not explained by BMI, body weight, or the presence of concurrent AN.
• HPA axis activation and serotonin dysregulation may be associated with decreased leptin in BN, potentially contributing to disinhibited eating.