Interrelationships between weight loss, body fat distribution and sex hormones in pre- and postmenopausal obese women.

Abstract

Relationships between regional body fat distribution and sex hormones as well as changes in sex hormones after weight loss were evaluated. All subjects were hospitalized in the Institute of Internal Medicine of the University of Verona. Twenty-six premenopausal (age 33.7 +/- 10.2 years) and 15 postmenopausal (age 57.9 +/- 5.9 years) obese women. Body weight, body-mass index, waist and hip circumferences, visceral fat by computed tomography and sex hormones were evaluated before and after 4 weeks on a very low energy diet. Body-mass index was higher in pre-than in postmenopausal women, although the difference was not significant. Total and free testosterone were significantly higher in the pre- than in the postmenopausal group (P < 0.001). Significant negative correlations were found between age and total testosterone (r = -0.65; P < 0.001), free testosterone (r = -0.54; P < 0.001), androstenedione (r = -0.46; P < 0.01) and urinary cortisol excretion (r = -0.50; P < 0.01). A negative correlation was found between visceral fat and total testosterone (r = -0.41; P < 0.01). After adjusting for age, the negative correlation between total testosterone and visceral fat encountered both in the subject group as a whole and in premenopausal women was no longer significant, whilst a significant negative association between visceral fat and sex hormone binding globulin (SHBG) (r = -0.56; P < 0.001) was always found. When step-down regression analysis was used to evaluate the joint effect of age, menopausal status, and anthropometric and metabolic variables on sex hormones, age was the most powerful independent variable for predicting total testosterone, free testosterone and androstenedione levels, whilst menopausal status was the most powerful predictor of FSH and LH levels. Changes in hormones after VLED were analysed separately in pre- and postmenopausal women. None of the hormones changed significantly after VLED in the postmenopausal group, except for FSH values. LH, free testosterone and urinary cortisol excretion values decreased significantly after VLED in the premenopausal group. Our data show that age, to a greater extent than visceral fat, seems to be negatively associated with steroid sex hormones. Weight loss seems to be associated with changes in sex hormones only in premenopausal women.