A randomized trial of estrogen or raloxifene during postmenopausal weight loss: Adiposity and cardiometabolic outcomes

OBJECTIVE: Estrogen-based hormone therapy (HT) attenuates abdominal fat gain after menopause, but whether HT improves abdominal fat loss during weight loss is unknown. We hypothesized that HT or a selective estrogen receptor modulator (raloxifene) would augment reductions in abdominal visceral fat during weight loss when compared to placebo, potentially increasing improvements in glucose tolerance and lipid profile. DESIGN AND METHODS: Healthy postmenopausal women (n=119; age 50–70y) underwent a 6-month weight loss (primarily exercise) intervention with randomization to raloxifene (60mg/d), HT (conjugated estrogens, 0.625mg/d), or placebo. We measured changes in total and abdominal (visceral and subcutaneous) fat mass, lipid profile, and fasting and post-challenge glucose and insulin. RESULTS: Neither HT nor raloxifene augmented loss of total or abdominal fat mass during exercise-induced weight loss when compared with placebo. Weight loss-induced improvements in risk factors were similar among the three groups, except for a greater reduction in fasted glucose in the HT group (difference in change [95%CI] from placebo; −0.40 [−0.76, −0.05]) and greater reductions in LDL (−0.36 [−0.63, −0.09]) and increases in HDL (0.15 [0.07, 0.24]) in both treatment groups. CONCLUSIONS: Postmenopausal HT and raloxifene did not increase abdominal fat loss during weight loss, but did improve some cardiometabolic outcomes.