Association between reproductive lifespan and risk of incident type 2 diabetes and hypertension in postmenopausal women: Findings from a 20-year prospective study

Abstract

BackgroundThis study examined the association between reproductive lifespan and incident type 2 diabetes mellitus (T2DM) and hypertension in mid-age women. Also, the combined effect of reproductive lifespan and body mass index (BMI) on the risks of T2DM and hypertension were explored. MethodsReproductive lifespan was defined as the difference between age at menopause and age at menarche, and categorized as <35, 35–37, 38–40, and ≥41 years based on the quartile distribution. A multivariable Cox proportional hazard regression was used, adjusting for socio-demographic, lifestyle, and reproductive factors. ResultsOf 6357 postmenopausal women included (mean [SD] age at last follow-up, 66.3[3.3] years), a total of 655 developed incident T2DM (10.3%) and 1741 developed hypertension (30.0%) during 20 years of follow-up. The total sample had a mean (SD) reproductive lifespan of 37.9 (4.5). Compared with the women who had a reproductive lifespan of 38–40 years, those with a short reproductive lifespan (<35 years) had a 30% increased risk of T2DM and twice the risk of hypertension. Under the combined model, women who had a short reproductive lifespan (<35 years) and who had a BMI ≥30 kg/m2 at baseline showed a higher risk of T2DM (HR: 6.30, 95% CI: 4.41–8.99) and hypertension (HR: 6.06, 4.86–7.55) compared with women who had a reproductive lifespan of 38–40 years and a BMI < 25 kg/m2. ConclusionsA higher risk of both incident T2DM and hypertension at midlife was found among women experiencing a shorter reproductive lifespan, with pronounced risk for women experiencing both a short reproductive lifespan (<35 years) and a higher baseline BMI (≥30 kg/m2). Women with a short reproductive lifespan may benefit from maintaining healthy body weight in midlife.