Synthetic conjugated estrogens-B and postmenopausal nocturnal vasomotor symptoms: a randomized controlled trial.

OBJECTIVE: To evaluate two doses of oral synthetic conjugated estrogens-B tablets compared with placebo on the frequency of awakenings resulting from nocturnal vasomotor symptoms in postmenopausal women over a 12-week treatment period.

METHODS: A double-blind, randomized, placebo-controlled multicenter study enrolled a total of 157 women who were experiencing daytime vasomotor symptoms and a minimum of at least three nocturnal awakenings per night as a result of hot flushes. Participants were evenly randomized to one of three treatment groups (0.3 mg, 0.625 mg, or matching placebo) and treated for up to 12 weeks. Subjective sleep quality also was assessed.

RESULTS: Significantly greater reductions from baseline in the weekly mean frequency of awakenings resulting from hot flushes occurred for participants randomized to either synthetic conjugated estrogens-B dose relative to placebo (mean reductions, 3.55, P=.004, and 4.65, P<.001 for 0.3 mg and 0.625 mg, respectively). In addition, a significantly greater proportion of participants at either estrogen dose had complete elimination of nocturnal awakenings (36.5% for 0.3 mg, 34% for 0.625 mg compared with 9.8% for placebo; P ≤.002) with a general finding of improved sleep based on actigraphy data. No differences were observed in measures of sleep quality or daytime sleepiness.

CONCLUSION: In this symptomatic postmenopausal population of women experiencing sleep disruption resulting from nocturnal vasomotor symptoms, a daily dose of synthetic conjugated estrogens-B as low as 0.3 mg appears to be effective in treating nocturnal hot flushes that lead to unwanted awakenings.

CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00592839.