The effect of hormone therapy on plasma homocysteine levels: a randomized clinical trial.

OBJECTIVE: An elevated plasma homocysteine level is a risk factor for cardiovascular diseases. Hormone therapy (HT) may reduce fasting plasma homocysteine levels. We studied 80 postmenopausal women to determine the effect of medroxyprogesterone acetate (MPA) combined with conjugated equine estrogens (CEE) on fasting plasma homocysteine levels.

DESIGN: In a randomized, double blind, prospective, placebo-controlled study, we randomly assigned 80 healthy postmenopausal women between CEE 0.625 mg/d combined with MPA 2.5 mg/d (n = 20), CEE 0.625 mg/d combined with MPA 5 mg/d (n = 20), unopposed CEE 0.625 mg/d (n = 20), and placebo (n = 20) all given for a duration of 6 months. Fasting plasma homocysteine levels were measured before and at the end of the treatment.

RESULTS: Before treatment, plasma homocysteine concentrations were similar in all groups. After 6 months of unopposed CEE, the mean fasting plasma homocysteine levels decreased by 19.02% when compared with baseline levels (P < 0.05). The mean fasting plasma homocysteine concentrations decreased by 17.63% and 19.56% from baseline in both the CEE plus MPA 2.5 mg/d and CEE plus MPA 5 mg/d groups, respectively (P < 0.05 for each group). In contrast, plasma homocysteine levels increased by 11.66% in the placebo group. The homocysteine lowering effect did not differ significantly among the three groups of women receiving unopposed CEE alone and CEE plus MPA at two different doses.

CONCLUSION: Six months of estrogen therapy (ET) and combined estrogen-progestogen therapy (EPT) significantly lower fasting plasma homocysteine levels in healthy postmenopausal women with equal efficacy.