Oestrogen-progestogen replacement therapy changes body composition in early post-menopausal women

Changes in body composition were investigated in a group of 136 post-menopausal women treated for at least 1 yr with combined oestrogen-progestogen therapy at three different doses, or a placebo. The body composition changes were evaluated using the urinary creatinine excretion rate as an indicator of lean body mass, and the changes in daily creatinine excretion were related to the changes in serum oestradiol and oestrone. The urinary creatinine excretion rate was significantly increased (P less than 0.001) in the group receiving high-dose hormones, and the urinary creatinine/body weight ratio was significantly increased (P less than 0.05) in all treated groups as compared with the placebo-group. The body weight remained unchanged in all groups. The relationships between the changes in daily creatinine excretion and the changes in serum oestradiol and serum oestrone were both significant (P less than 0.05). The present study suggests that high-dose post-menopausal hormone therapy changes the body composition by increasing the muscle mass and that, since the body weight remains unchanged, a proportionate decrease in the fat mass seems to occur.