The postmenopausal estrogen/progestin interventions study: primary outcomes in adherent women

Objective: To assess the efficacy of unopposed estrogen, and three estrogen/progestin regimens on selected heart disease risk factors among adherent women and to contrast those results with efficacy among all women in the PEPI study. Design: A 3-year, multicenter, randomized, double-blinded, placebo-controlled clinical trial. Participants: A total of 847 healthy postmenopausal women aged 45 to 64 years of age with no known contraindication to hormone therapy, who attended their 36 month clinical visit. Intervention: Participants were randomized in equal numbers to one of the following treatments: (1) placebo; (2) conjugated equine estrogen (GEE) 0.625 mg daily; (3) CEE 0.625 daily plus medroxyprogesterone acetate (MPA) 10 mg, days 1-12; (4) CEE 0.625 daily plus MPA 2.5 mg daily; or (5) CEE 0.625 daily plus micronized progesterone (MP) 200 mg, days 1-12. Analysis: Analyses are based on adherent women, where adherence is defined as taking at least 80% of pills at each B-month visit. Results: Adherence rates were high in all groups except women with a uterus assigned to unopposed GEE. The difference in HDL-C levels resulting from the CEE vs. CEE + MP was approximately three times larger than in the intent-to-treat analyses, reaching statistical significance (P < 0.05). In each active treatment, LDL-C decreased 10-15%. Triglycerides increased 15-20% in each opposed CEE arm and over 25% in the CEE only arm; this difference was not statistically significant. Fibrinogen increased by 7% among placebo adherers, but decreased or remained fairly stable among the active arm adherers. Systolic blood pressure increased 3-5% in all treatment arms. Women adherent to the CEE + MPA arms had twice the increase of 2 h glucose levels as women adherent to CEE only, or CEE + MP (8-9% vs. 3-4%). Two-hour, insulin levels decreased 3-12% for all arms. The patterns of change for fibrinogen, SEP, 2 h glucose and insulin were similar to those from the intent-to-treat analyses. Conclusions: In analyses limited to adherent women, all active treatments, compared to placebo, continued to have similar and favorable effects on LDL-cholesterol and fibrinogen and no significant effects on blood pressure or insulin levels. Given the overall high adherence rates in PEPI, the results are similar to the intent-to-treat analyses, as expected. Only the trend of HDL-C to have a larger increase in the CEE only arm (in the intent-to-treat analyses) gained statistical significance in analyses restricted to adherers. (C) 1997 Elsevier Science Ireland Ltd.