The influence of menopause and body mass index on serum leptin concentrations

The aim of this study was to evaluate the influence of menopausal status, serum estradiol and body mass index (BMI) on serum leptin concentration in a large sample of pre- and postmenopausal women.

434 healthy women (mean age +/-s.d., 52.2 +/- 10.3 years) were recruited at the University of Marburg on the occasion of a routine gynecological visit. Two hundred and eighteen (50.2%) women were premenopausal (mean age, 36.5 +/- 10.4 years) and not on oral contraceptives or hormone replacement therapy (HRT) and 216 (49.8%) women were postmenopausal (mean age 61.8 +/- 8.9 years) not on HRT. To evaluate the influence of menopausal status, estradiol level and BMI on serum leptin concentrations, women were allocated to one of the four groups: (a) premenopausal women BMI <25 kg/m(2) (n=137), (b) premenopausal women BMI >25 kg/m(2) (n=81), (c) postmenopausal women BMI <25 kg/m(2) (n=94) and (d) postmenopausal women BMI >25 kg/m(2) (n=122).

Irrespective of the menopausal status, women with a BMI >25 kg/m(2) had significantly higher leptin concentrations in all age groups compared with women with a BMI <25 kg/m(2) (P<0.001). The multiple linear regression analyses showed that BMI was the only statistically significant independent predictor for leptin. In comparison to postmenopausal women, premenopausal women showed a significantly lower mean age, weight, BMI and FSH concentration (P<0. 001), a higher mean height and serum estradiol (P<0.01 and P<0.001 respectively) but significantly lower serum leptin concentration (P<0.01). The multiple linear regression model showed no significant influence of menopausal status or serum estradiol on serum leptin concentration, even after controlling for BMI.

Serum leptin concentrations are significantly higher in pre- and postmenopausal obese women, compared with normal weight controls. Serum leptin concentrations are not influenced by menopausal status or serum estradiol level.