Factors Related to Age at Natural Menopause: Longitudinal Analyses From SWAN

TLDR

Early age at natural menopause is linked to adverse health outcomes and may signal future ill health, yet longitudinal studies of modifiable factors in diverse populations are lacking. This study aimed to examine longitudinally the influence of modifiable sociodemographic, lifestyle, and health factors on age at natural menopause in a large, diverse cohort. Using data from 3,302 premenopausal and early perimenopausal women across seven U.S. sites and five racial/ethnic groups (1996–2007), the authors applied Cox proportional hazards models to assess time‑invariant and time‑varying factors related to age at natural final menstrual period.

Abstract

Early age at the natural final menstrual period (FMP) or menopause has been associated with numerous health outcomes and might be a marker of future ill health. However, potentially modifiable factors affecting age at menopause have not been examined longitudinally in large, diverse populations. The Study of Women's Health Across the Nation (SWAN) followed 3,302 initially premenopausal and early perimenopausal women from 7 US sites and 5 racial/ethnic groups, using annual data (1996–2007) and Cox proportional hazards models to assess the relation of time-invariant and time-varying sociodemographic, lifestyle, and health factors to age at natural FMP. Median age at the FMP was 52.54 years (n = 1,483 observed natural FMPs). Controlling for sociodemographic, lifestyle, and health factors, we found that racial/ethnic groups did not differ in age at the FMP. Higher educational level, prior oral contraceptive use, and higher weight at baseline, as well as being employed, not smoking, consuming alcohol, having less physical activity, and having better self-rated health over follow-up, were significantly associated with later age at the FMP. These results suggest that age at the natural FMP reflects a complex interrelation of health and socioeconomic factors, which could partially explain the relation of late age at FMP to reduced morbidity and mortality.