Evidence that insulin and androgens may participate in the regulation of serum leptin levels in women.

OBJECTIVE

Although serum leptin is principally influenced by body mass, to understand the role of insulin and androgens in the regulation of serum leptin in normal weight women.

DESIGN

Prospective observational study.

SETTING

Academic practice in reproductive endocrinology.

PATIENT(S): Twenty-one women with polycystic ovary syndrome (PCOS) of normal body weight, 8 apparently normal women with polycystic-appearing ovaries (PAO), and 21 normal women.

INTERVENTION(S): Fasting blood levels of luteinizing hormone, follicle-stimulating hormone, testosterone (T), unbound T, dehydroepiandrosterone sulfate (DHEAS), insulin, insulin growth factor-binding protein-1 (IGFBP-1), and leptin.

MAIN OUTCOME MEASURE(S): Comparisons of measured hormones in the different groups and correlative analysis

RESULT(S): Women with PCOS had higher levels of serum luteinizing hormone, T, unbound T, DHEAS and insulin, and lower levels of IGFBP-1 compared with the normal controls, but they had similar leptin levels. Normal women with PAO had increased levels of insulin and leptin compared with controls, whereas IGFBP-1 was lower in PAO. In normal weight women with PCOS and PAO, leptin correlated positively with body weight and insulin, and negatively with IGFBP-1 and DHEAS.

CONCLUSION(S): In normal weight patients serum leptin levels may be regulated in part by insulin. Androgens, on the other hand, may play a role in suppressing serum leptin.