Interleukin-6-597G/A and -572C/G polymorphisms and risk of coronary heart disease

Objective: To explore the relationship between interleukin-6 (IL-6) gene polymorphisms and the risk of coronary heart disease (CHD).

Methods: IL-6/-597G/A and -572C/G polymorphisms were genotyped in 245 CHD patients and 260 healthy adults by PCR-RFLP. Serum IL-6 level was examined by ELISA. Logistic regression was performed to observe the relationship between IL-6/-572C/G polymorphism and other risk factors of CHD.

Results: IL-6/-597G/A genotype was similar between the two groups. The frequencies of IL-6/-572C/G genotype and G allele were more frequent in patients with CHD than that in controls (P < 0.01). Compared with CC genotype, the relative risk for CHD in people with CG and GG genotypes was 1.46 (95% CI: 1.01 - 2.10, P < 0.05) and 5.19 (95% CI: 1.69 - 15.89, P < 0.01), respectively. The serum levels of IL-6 were similar between carriers of the IL-6/-572G allele and patients with CC genotype (P > 0.05). IL-6/-572 C/G is related to total cholesterol (OR 1.76, 95% CI: 1.05 - 3.16, P < 0.05) and triglyceride (OR = 2.51, 95% CI: 1.04 - 6.45, P < 0.05), respectively.

Conclusions: IL-6/-597G/A polymorphism was not associated with susceptibility to CHD, but IL-6-572C/G polymorphism may be a possible genetic susceptibility factor for CHD in Chinese Hans population.