Increased Burden of Cardiovascular Disease in Carriers of APOL1 Genetic Variants
Rationale: Two distinct alleles in the gene encoding apolipoprotein L1 (APOL1), a major component of HDL, confer protection against Trypanosoma brucei rhodesiense infection and also increase risk for chronic kidney disease (CKD). Approximately 14% of African-Americans carry two APOL1 risk alleles, accounting for the high CKD burden in this population.
Objective: We tested whether APOL1 risk alleles significantly increase risk for atherosclerotic cardiovascular disease (CVD) in African-Americans.
Methods and Results: We sequenced APOL1 in 1959 randomly selected African American participants in the Jackson Heart Study (JHS) and evaluated associations between APOL1 genotypes and renal and cardiovascular phenotypes. Previously identified association between APOL1 genotypes and CKD were confirmed (p=2.4 x 10-6). Among JHS participants with two APOL1 risk alleles, we observed increased risk for CVD (50/763 events among participants without vs. 37/280 events among participants with two risk alleles; odds ratio (OR): 2.17, p=9.4 x 10-4). We replicated this novel association of APOL1 genotype with CVD in Women's Health Initiative (WHI) participants (66/292 events among participants without vs. 37/101 events among participants with two risk alleles; OR: 1.98, p=8.37 x 10-3; JHS and WHI combined, p=8.5 x 10-5; OR: 2.12). The increased risk for CVD conferred by APOL1 alleles was robust to correction for both traditional CVD risk factors and CKD.
Conclusions: APOL1 variants contribute to atherosclerotic CVD risk, indicating a genetic component to cardiovascular health disparities in individuals of African ancestry. The considerable population of African Americans with two APOL1 risk alleles may benefit from intensive interventions to reduce CVD.
- risk factors
- genetic epidemiology
- genetic association
- cardiovascular genomics
- chronic kidney disease
- race and ethnicity
- Received August 2, 2013.
- Revision received December 20, 2013.
- Accepted December 30, 2013.