Effects of hormone replacement therapy on serum lipids in elderly women. a randomized, placebo-controlled trial.

BACKGROUND: Coronary heart disease (CHD) is the leading cause of death among older women. In observational studies, the incidence of CHD has been reduced in postmenopausal women who take hormone replacement therapy (HRT). A low serum level of high-density lipoprotein (HDL) cholesterol is one of the risk factors predictive of death from CHD.

OBJECTIVE: To determine the effects of HRT on serum lipid and lipoprotein levels in elderly women.

DESIGN: Randomized, double-blind, placebo-controlled trial.

SETTING: University research center.

PARTICIPANTS: 59 sedentary women 75 years of age or older.

INTERVENTION: Participants were assigned to 9 months of oral therapy with placebo or conjugated estrogens, 0.625 mg/d, plus trimonthly medroxyprogesterone acetate, 5 mg/d for 13 days.

MEASUREMENTS: Serum lipid and lipoprotein levels.

RESULTS: After 9 months of treatment, women in the HRT group compared with women in the placebo group had decreased low-density lipoprotein cholesterol levels (mean change [+/-SD], -0.47 +/- 0.69 mmol/L [-18.2 +/- 26.5 mg/dL] vs. -0.06 +/- 0.32 mmol/L [-2.2 +/- 12.2 mg/dL], respectively; between-group difference, 0.41 mmol/L [95% CI, 0.09 to 0.74 mmol/L], 16 mg/dL [95% CI, 3.5 to 28.5 mg/dL]; P = 0.01) and increased HDL cholesterol levels (mean change, 0.21 +/- 0.27 mmol/L [8.1 +/- 10.5 mg/dL] vs. 0.06 +/- 0.11 mmol/L [2.4 +/- 4.3 mg/dL], respectively; between-group difference, 0.15 mmol/L [CI, 0.008 to 0.29 mmol/L], 5.7 mg/dL [CI, 0.8 to 10.6 mg/dL]; P = 0.02). The observed changes were independent of age at menopause onset, baseline lipid values, body weight, waist circumference, percentage body fat, and peak aerobic power.

CONCLUSIONS: In women 75 years of age or older, HRT improved the lipoprotein profile to the extent observed previously in younger postmenopausal women. Further studies are needed to evaluate whether these effects protect against CHD in this population.