Sex and ethnicity differences in coronary heart disease: A UK-based tri-ethnic cohort analysis
TL;DR
Ethnic minority female participants do not have the same protection from CHD as Europeans, and greater cardiometabolic burden may drive this elevated CHD risk and loss of female protection.
Abstract
Background and aims: Sex differences in ethnic minority risk of coronary heart disease (CHD) are often overlooked. Here we aim to explore sex-by-ethnicity differences in CHD outcomes and the contribution of risk factors. Methods: Incident CHD events were identified for Europeans, and South Asian and African/African Caribbean first generation migrants in the UK-based Southall and Brent Revisited (SABRE) cohort. Cardiovascular risk factors were assessed at baseline (1988-91). Cox proportional hazards models quantified group differences in CHD incidence and risk factor contribution. Population attributable fractions (PAFs) described risk factor contribution to group differences. Results: Among 4,754 participants followed for 40.8 years, 1,710 CHD first events occurred. Cumulative incidence of CHD was highest in South Asian males (65% by age 90) and females (55%), compared with 52% in European males and 24-31% in other groups. Sex differences in CHD incidence were pronounced in Europeans (female versus male HR=0.45, 95% CI [0.37,0.55]) but attenuated in South Asians (0.68 [0.56,0.82]) and African/African Caribbeans (0.79 [0.57,1.10]). CHD risk was higher in South Asian compared to European men (1.80 [1.63,1.99]). This ethnic difference was greater in females (2.44 [1.88,3.17]). PAFs for diabetes (PAF=18.0%, 95% CI [6.2,29.8]), hypercholesterolemia (44.2% [20.4,68.1]), and hypertriglyceridemia (22.4% [7.9,37.0]) made a greater contribution to the risk of CHD in South Asian females compared to all other groups. Conclusions: Ethnic minority female participants do not have the same protection from CHD as Europeans. Greater cardiometabolic burden may drive this elevated CHD risk and loss of female protection.