Body composition, visceral fat distribution and fat oxidation in postmenopausal women using oral or transdermal...

The aim of this study was to observe hysterectomized postmenopausal women (without progestogen, which could interfere in the results), using oral-conjugated oestrogen 0.625 mg daily (n=13) or 17beta-estradiol transdermal patches delivering 50 microg daily (n=10) during 12 months, and to evaluate the treatment effects on body composition, visceral fat distribution, energy expenditure and substrate oxidation.

We studied 23 postmenopausal women using oral-conjugated oestrogen (Premarin) 0.625 mg daily (n=13) or transdermal oestrogen patches (Systen TTS) 50 microg daily (n=10). Body composition was measured by DEXA, visceral adipose tissue areas were measured by abdominal computed tomography, and energy expenditure, fat oxidation and carbohydrate oxidation were measured by indirect calorimetry (Deltatrac Metabolic Monitor).

There were: (1) a decrease in IGF-I and an increase in GH levels in the oral group and no change in the transdermal group; (2) a increase in lean body mass in the transdermal group and a decrease in the oral group; (3) a increase in total body fat mass in the oral group and no change in the transdermal group; (4) an increases in total bone mass and in total bone mineral density in the transdermal group and no change in the oral group; (5) an increase in lipid oxidation in the transdermal group and a decrease in the oral group, and (6) no significantly change about weight, visceral adipose tissue areas and energy expenditure in both groups.

The administration route of oestrogen replacement therapy in postmenopausal women confers distinct and divergent effects on body composition and substrate oxidation during 12-months treatment.