Serum leptin concentration in women: effect of age, obesity, and estrogen administration

Objective: To compare serum leptin levels in normally cycling reproductive females (20-35 years old) with those in age-matched males, in women who were receiving oral contraceptives, and in older (postmenopausal) women (50-65 years old) who were or who were not receiving hormone replacement therapy. Design: Case-control study. Setting: Obstetrics and Gynecology Clinic, Texas Tech University Health Sciences Center-Amarillo, or the Exercise Physiology Laboratory at Southeastern Louisiana University. Patient(s): Normally cycling women between the ages of 20-35 years and age-matched controls who were receiving oral contraceptives. Postmenopausal women between the ages of 50-65 years who were or who were not receiving hormone replacement therapy. Main Outcome Measure(s): Serum leptin concentration. Result(s): In all groups, serum leptin concentrations were correlated significantly with body mass index. Leptin levels were significantly higher in young women than young men (P <.001), but no other statistically significant differences were found for the other three comparisons. Conclusion(s): Serum leptin concentrations expressed as a measure of adiposity (body mass index) are greater in young normally cycling females (20-35 years old) than in age-matched males. There is no difference in levels of serum leptin between young and postmenopausal (50-65 years old) women. Estrogen administration, either in young women who are receiving estrogen-progestin oral contraceptives or in postmenopausal women who are receiving hormone replacement therapy, does not effect serum leptin concentrations. (Fertil Steril(R) 1998;70:472-7. (C)1998 by American Society for Reproductive Medicine.).