Association study of CRP gene polymorphism and hypertension in Han Chinese population

Background: Serum C-reactive protein (CRP) and genetic variation of CRP gene have been reported as a strong, independent predictor of myocardial infarction and stroke. But there is rare association evidence of CRP genetic variation and hypertension (HT).

Methods: A community-based case-control study including 1331 cases with HT and 1400 controls was used to evaluate the association of tagSNPs covered CRP gene, CRPP1 gene and 40kb upstream with HT in a Chinese Han population. Haplotypes and stratification analysis were applied to further evaluate relationships between the screened SNPs and HT and general linear model (GLM) was applied to compare blood pressure levels between genotypes.

Results: In stage 1, five SNPs had positive association with HT (P<0.05) and entered stage 2 and two SNPs rs876537 and rs10737175 polymorphisms showed significant association with HT in joint sample. Haplotype analysis showed that comparing with common haplotype T-C which was constructed by rs6677719 and rs10737175, haplotype T-T significantly associated with HT after adjusted covariates. Stratification analysis found significant associations of HT for rs876537, rs2808630, rs6677719 and rs10737175 in ≥50years group, rs876537, rs10737175 in female, rs876537 and rs10737175 in non-smoking and non-drinking populations as well as rs2808630 in non-drinking population. Furthermore, quantitative trait analysis indicated significant differences of SBP and DBP between the genotypes of rs10737175, rs876537 and rs2808630 in non-treatment hypertensive cases and control population.

Conclusions: The findings of this study support that CRP gene polymorphisms have significant association with genetic susceptibility of HT and quantitative traits of blood pressure.