Relationship between hormone replacement therapy use with body fat distribution and insulin sensitivity in obese postmenopausal women

The aim of this study was to compare the effect of hormone replacement ther apy (HRT) on insulin resistance and central adiposity in obese postmenopaus al women. Forty-five obese postmenopausal women (16 HRT users and 29 nonuse rs), with a mean age of 56.6 +/- 5.3 years and duration of current, continu ous HRT use of 4.7 +/- 2.9 years, were included in the study. Subjects were studied using oral glucose tolerance tests, euglycemic clamping, dual phot on x-ray absorptiometry, computed tomography, doubly labeled water, and tre admill testing. Insulin sensitivity, total fat, visceral fat, subcutaneous abdominal fat, thigh muscle attenuation, daily physical activity energy exp enditure, peak oxygen consumption (Vo(2)) were measured. HRT users had lowe r body weight (88.0 +/- 11.0 v 98.2 +/- 15.0 kg, P = .05), lower body mass index (33.1 +/- 3.5 v 36.8 +/- 5.2 kg/m(2), P = .05), lower fat mass (38.3 +/- 7.3 v 44.1 +/- 10 kg, P = .05), less visceral adipose tissue (157 +/- 4 7 v 211 +/- 81 cm(2); P = .05), and higher peak Vo(2) (21.1 +/- 4.6 v 17.6 +/- 2.2 mL/kg/min, P = .001) than nonusers. After adjustment for total fat, we noted a trend for decreased visceral adipose tissue in HRT users (P = . 09). After adjustment for peak Vo(2), the decreased visceral adipose tissue persisted in HRT users (P < .01). Insulin sensitivity per killogram of lea n body mass did not differ between HRT users (0.51 +/- 0.22 mmol/kg/min) an d nonusers (0.49 +/- 0.22 mmol/kg/min). It was concluded that obese postmen opausal women using HRT have a more favorable body composition and fat dist ribution pattern than nonusers. Although visceral adipose tissue is decreas ed in HRT users, insulin sensitivity does not differ between HRT users and nonusers. Copyright (C) 2001 by W.B. Saunders Company.