Abstract Body (Do not enter title and authors here): Background and research questions: Data suggest that South Asian women exhibit earlier development of cardiovascular disease and that they may also experience menarche and menopause at younger ages than other ethnic groups. We investigated whether the timing of menarche and menopause impacts the trajectories of blood pressure in postmenopausal women in India.

Methods: Data were from 1,689 postmenopausal women free of cardiovascular disease at baseline in the Delhi and Chennai sites of the Centre for cArdiometabolic Risk Reduction in South-Asia (CARRS) surveillance Cohort. Women underwent blood pressure examinations at their homes in 2010-2012, 2013-2014, and 2016-2017. We assessed associations of ages at menarche (tertiles: 9-13, 14, and 15-22 years) and menopause (four categories: <40, 40-44, 45-49, and ≥50 years), separately, with baseline systolic blood pressure (SBP) and trajectories of SBP change from baseline to the last available examination round. Associations were assessed using multilevel modeling, controlling for age, education, employment status, religion, body mass index, and hypertension diagnosis and/or use of antihypertensive medication at baseline.

Results: Women had a median age of 54 years (IQR: 48-60) at baseline and median follow-up time was 4.8 years (IQR: 4.1-5.2). Median age at menarche was 14 years (IQR: 13-15) and median age at menopause was 45 years (IQR: 40-48). Adjusted models showed no association between age at menarche and baseline SBP. Longitudinally, the percent change in SBP per year was higher for those who had menarche before age 14 (0.83, 95% CI: 0.53-1.14) and after age 14 (0.70, 95% CI: 0.38-1.04) compared to menarche at 14 years (0.25, 95% CI: -0.06-0.55). There were no statistically significant associations of age at menopause with baseline SBP or change in SBP.

Conclusions: The timing of menarche, but not menopause, was associated with blood pressure trajectories among postmenopausal Indian women. Further work to understand the mechanisms linking reproductive milestones and blood pressure trajectories as well as their implications for cardiovascular outcomes in South Asian women is needed.