Abstract P120: Women With Menopause After Age 45 and Take Hormone Therapy After Age 60 Increase the Risk of Cardiovascular Disease

Abstract

Introduction: Evidence from clinical trials and observational studies on the relationship between menopausal hormone therapy (MHT) and cardiovascular disease (CVD) risk has been discordant. Hypothesis: We hypothesized that the association between MHT and risk of CVD might be affected by both age at menopause and age when initiated MHT. Methods: We harmonised and pooled individual-level data from 15 studies across five countries/regions (Australia, Scandinavia, USA, Japan, and UK). Postmenopausal women who had reported their MHT status (user or non-user) and CVD status (occurred or not, including coronary heart disease (CHD) and stroke) were included. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for the association between MHT use and incident CVD. We stratified the analyses by age when initiated MHT and age at natural menopause to examine the interaction between MHT, age initiated MHT, and age at menopause on incident CVD. Results: Overall, 190 625 postmenopausal women were included. We identified 10 601 incident CVD events, including 7615 CHD and 3543 strokes. Around 39% (74 585) women were MHT users. Compared to non-users of MHT, women who were MHT users had 10% higher risk of incident CVD (HR 1.10, 95% CI 1.06-1.14), with HR (95% CI) of (1.15, 1.10-1.20) for CHD and (1.02, 0.96-1.09) for stroke. After stratifying by age at natural menopause, women who experienced menopause after age 45 years and took MHT had around 15% higher risk of CHD, while the significant association with incident stroke was only observed in women who had menopause after 55 years (1.16, 1.01-1.33). After a further stratification by age initiated MHT, we found the significant associations between MHT users and incident CVD were only observed in women who experienced menopause after age 45 years and took MHT at age 60 years or old (Table 1). Conclusions: Postmenopausal women who experienced natural menopause after age 45 years and took MHT after age 60 years had increased risk of incident CVD.