Genetic associations with carotid intima-media thickness link to atherosclerosis biology with sex-differences in sub-Saharan Africans

Abstract Atherosclerosis precedes the onset of many clinical manifestations of cardiovascular diseases (CVDs). We used carotid intima-media thickness (cIMT) to investigate genetic susceptibility to atherosclerosis in 7894 unrelated adults (3963 women, 3931 men) aged 40 to 60 years resident in four sub-Saharan African countries. cIMT was measured by ultrasound and genotyping was performed on the H3Africa SNP Array. Two new African-specific genome-wide significant loci, SIRPA (p=4.7E-08), and FBXL17 (p=2.5E-08), were identified in the combined dataset. Sex-stratified analysis revealed associations with two male-specific loci, SNX29 (p=6.3E-09) and MAP3K7 (p=5.3E-08), and two female-specific loci, LARP6 (p=2.4E-09) and PROK1 (p=1.0E-08). Regional associations were replicated with known risk loci for atherosclerosis and CVDs with different lead SNPs than in Europeans and significant enrichment for oestrogen response genes for female-specific signals were identified. The genes identified showed biological relevance to atherosclerosis and/or CVDs, as well as sex-differences and transferability of signals from non-African studies.