Polymorphism of the C-reactive protein (CRP) gene is related to serum CRP level and arterial pulse wave velocity in healthy elderly Japanese

Abstract

The objective of this study was to clarify relationships between the C-reactive protein (CRP) gene and both the serum level of CRP and arterial pulse wave velocity (PWV), using haplotype analysis of healthy elderly Japanese. Five single-nucleotide polymorphisms (SNPs) of the human CRP gene (rs1341665, rs3091244, rs1800947, rs1130864 and rs1205) were used to genotype 315 healthy elderly Japanese subjects (mean age, 77.9±14.1 years; male/female ratio, 0.96). Linkage disequilibrium was analyzed for the five SNPs. The frequency of each haplotype and diplotype was estimated using the expectation/maximization (EM) algorithm. There were statistically significant associations between the CRP level and two CRP genotypes; the p value for the T allele of rs3091244 (CT+AT+TT vs. CC+CA+AA) was 0.002 (95% confidential interval [CI], 2.1-24), and the p value for the T allele of rs1130864 (TT+TC vs. CC) was 0.002 (95% CI, 2.1-24). The only genotype that was significantly associated with arterial PWV was the C allele of rs1800947, with a p value of 0.039. The haplotype was constructed using rs1341665, rs3091244 and rs1800947, in that order. There was a significant association between the CRP level and the T-T-G haplotype, with a p value of 0.002 (95% CI, 2.1-24). There was a significant association between arterial PWV and the C-C-C haplotype, with a p value of 0.039. We concluded that rs3091244, rs1130864 and the T-T-G haplotype are genetic markers for elevated basal CRP levels. rs1800947 and the C-C-C haplotype appear to be susceptibility markers for atherosclerosis, but this requires confirmation.