Leptin concentrations in the abdominal subcutaneous adipose tissue of patients with anorexia nervosa assessed by in vivo microdialysis

Objective: The adipocyte-derived hormone leptin is involved in energy metabolism and body weight regulation. Plasma leptin concentrations are significantly reduced in patients with anorexia nervosa (AN) and with severe malnutrition. Whether reduced plasma leptin is reflected by its decreased production by the adipose tissue is unknown. Methods: In the present study we measured leptin concentrations locally in the abdominal subcutaneous adipose tissue of 9 female AN patients and 11 healthy controls by in vivo microdialysis. Results: Adipose tissue free leptin levels were not different in patients with AN compared to controls (2.59 +/- 1.99 vs 2.36 +/- 0.25 ng/ml, P > 0.05). Plasma leptin soluble receptor (sOb-R) levels were significantly higher in patients with AN than in healthy subjects (58.05 +/- 38.69 vs 12.79 +/- 5.08 U/ml, P < 0.01). The area of adipocyte in AN was considerably smaller than in the controls (183 +/- 104.01 mu m(2) compared to 2145.8 +/- 1003.41). Conclusions: We conclude that decreased plasma leptin levels in patients with AN are not directly related to dialysate leptin levels in the abdominal subcutaneous adipose tissue. (c) 2004 Published by Elsevier B.V.