Local estrogen therapy (ET) can improve vaginal atrophy symptoms and associated cellular changes in postmenopausal women. This study evaluated whether age at the start of treatment influences response.
This post hoc analysis used data from a double-blind, randomized, placebo-controlled trial (NCT00108849), which treated 205 postmenopausal women aged ≥45 years with 10 μg vaginal ET for 52 weeks.
Women aged <60 or ≥60 years at treatment start were evaluated according to the following: vaginal maturation index (assessed by vaginal cytology samples), vaginal pH, and most bothersome symptom (both graded on four-point scales). Covariance analysis aimed to evaluate mean change differences between groups from baseline–week 52.
Vaginal ET improved vaginal maturation index (for all cell layers), vaginal pH, and symptom scores for both age groups. However, cytological profiles were significantly different in the <60 (n = 143) versus ≥60 years group (n = 55, estimated effect: –3.7, P
= 0.0003 [parabasal cells]; 5.8, P
= 0.0002 [intermediate cells]), indicating reduced cellular responsiveness to treatment among older women. Treatment effect on vaginal pH was less for older women, with a between-group difference of –0.19 (standard error = 0.05; P
Findings suggest that treatment may be initiated at any age since low-dose vaginal ET improved symptoms and signs of vaginal atrophy in both younger (<60 years) and older (≥60 y) women. The stronger response observed in younger women supports current clinical recommendations to start treatment early. Continued treatment may be important to avoid recurrence of vaginal atrophy.