Vaginal estrogen use and chronic disease risk in the Nurses' Health Study

Objective: To examine the associations between vaginal estrogen use and multiple health outcomes including cardiovascular disease (total myocardial infarction, stroke, and pulmonary embolism/deep vein thrombosis), cancer (total invasive, breast, endometrial, ovarian, and colorectal cancer), and hip fracture. Methods: We included postmenopausal women from the Nurses' Health Study (1982-2012) who were not current users of systemic hormone therapy at the start of the study or during follow-up. Vaginal estrogen use was self-reported on the biennial questionnaires. Information on incident health outcomes were self-reported and confirmed by medical records. We used Cox proportional hazards regression to model the multivariable adjusted hazard ratios and the 95% confidence intervals for vaginal estrogen use and multiple health outcomes. Results: Over 18 years of follow-up, after adjusting for covariates, risks for cardiovascular disease, cancer, and hip fracture were not different between users and nonusers of vaginal estrogen. No statistically significant increase in risk of any health outcome was observed with vaginal estrogen use. In sensitivity analyses, when we examined associations by hysterectomy status, the stratified results were generally similar to those for the total cohort. Conclusions: Vaginal estrogen use was not associated with a higher risk of cardiovascular disease or cancer. Our findings lend support to the safety of vaginal estrogen use, a highly effective treatment for genitourinary syndrome of menopause.