Objective: To evaluate the impact of different dosages of medroxyprogesterone acetate (MPA) on metabolism and hemostasis in postmenopausal women treated with conjugated estrogens.
Methods: In this prospective, double-blind study, 525 women were randomized to five treatment groups at 26 sites in the United States and Europe. All participants received 0.625 mg conjugated estrogens daily for up to 13 cycles; four groups also received MPA, either 2.5 or 5.0 mg/day continuously or 5.0 or 10.0 mg/day for the last 14 days of each cycle. Effects on lipid and carbohydrate metabolism and coagulation were evaluated.
Results: Beneficial changes in plasma lipid levels occurred in all groups, but were greatest with conjugated estrogens alone (P < or = .05). Fasting glucose and insulin levels were significantly lower and the insulin response to glucose challenge was significantly blunted in all groups (P < or = .05). No major changes of clinical significance occurred in hemostatic levels.
Conclusions: Metabolic levels were not affected adversely by the addition of MPA to conjugated estrogens, but some beneficial changes were greater with conjugated estrogens alone. Hemostatic levels were not affected.