Burden of Risk Alleles for Hypertension Increases Risk of Intracerebral Hemorrhage
Background and Purpose—Genetic variation influences risk of intracerebral hemorrhage (ICH). Hypertension (HTN) is a potent risk factor for ICH and several common genetic variants (single nucleotide polymorphisms [SNPs]) associated with blood pressure levels have been identified. We sought to determine whether the cumulative burden of blood pressure-related SNPs is associated with risk of ICH and pre-ICH diagnosis of HTN.
Methods—We conducted a prospective multicenter case–control study in 2272 subjects of European ancestry (1025 cases and 1247 control subjects). Thirty-nine SNPs reported to be associated with blood pressure levels were identified from the National Human Genome Research Institute genomewide association study catalog. Single-SNP association analyses were performed for the outcomes ICH and pre-ICH HTN. Subsequently, weighted and unweighted genetic risk scores were constructed using these SNPs and entered as the independent variable in logistic regression models with ICH and pre-ICH HTN as the dependent variables.
Results—No single SNP was associated with either ICH or pre-ICH HTN. The blood pressure-based unweighted genetic risk score was associated with risk of ICH (OR, 1.11; 95% CI, 1.02–1.21; P=0.01) and the subset of ICH in deep regions (OR, 1.18; 95% CI, 1.07–1.30; P=0.001), but not with the subset of lobar ICH. The score was associated with a history of HTN among control subjects (OR, 1.17; 95% CI, 1.04–1.31; P=0.009) and ICH cases (OR, 1.15; 95% CI, 1.01–1.31; P=0.04). Similar results were obtained when using a weighted score.
Conclusion—Increasing numbers of high blood pressure-related alleles are associated with increased risk of deep ICH as well as with clinically identified HTN.
- Received April 4, 2012.
- Revision received June 15, 2012.
- Accepted June 20, 2012.
- © 2012 American Heart Association, Inc.