Genetic ancestry and risk of atrial fibrillation in individuals of Black ethnicity in the UK Biobank
Chang Liu, Yan V Sun, Linzi Li, Lindsay J Collin, Amit J Shah, Alvaro AlonsoBackground
Black individuals have a lower incidence of atrial fibrillation (AF) than White individuals, despite a higher burden of traditional risk factors. Prior studies have suggested that European genetic ancestry may contribute to this paradox, but findings have been inconsistent.
Methods
We examined the association between European genetic ancestry and incident AF among 6920 UK Biobank (UKB) participants who self-identified as Black and were free of AF at baseline. European ancestry proportions were estimated by comparing participants to HapMap populations and were analysed both continuously and categorically using Cox proportional hazards models. Non-linear associations were evaluated using flexible spline curves. We then conducted a meta-analysis combining these results with those from the Atherosclerosis Risk in Communities Study, the Cardiovascular Health Study and the Women’s Health Initiative.
Results
During a median follow-up of 13.7 years, 205 (3%) participants developed incident AF. Each 10% increase in European ancestry was non-significantly associated with increased AF risk (HR 1.07 (95% CI 0.95 to 1.20)), and individuals in the highest European ancestry category had a higher AF incidence rate compared with all other categories. Random-effects meta-analysis of all four cohorts yielded a pooled relative risk (RR) of 1.09 (95% CI 0.99 to 1.21), with substantial heterogeneity largely driven by the Women’s Health Initiative (WHI) study. Excluding WHI resulted in a pooled estimate (RR 1.14 (95% CI 1.05 to 1.23)) without heterogeneity.
Conclusion
In UKB, European ancestry proportion was not significantly linked to incident AF, and pooled cross-cohort results were heterogeneous. Excluding WHI in sensitivity analyses produced a modest positive pooled association with no heterogeneity.