RESUMO
This study was aimed to explore the correlation between IL-6 gene promoter polymorphisms and coronary heart disease (CHD) by investigating the polymorphisms (-572G/C, -597G/A) in IL-6 gene promoter area, body mass index (BMI), inflammatory factors and other biochemical parameters in Han nationality of North China. The genotypes of IL-6 gene promoter-572G/C, -597G/A were detected by fluorescent probe hybridization with fluorescent resonance energy transfer and melting curve techniques in 194 CHD patients and 123 healthy people as control. The effects of genotype on plasma lipids, apoproteins, high sensitive C-reactive protein (hsCRP) and BMI were also studied. Logistic regression was performed to observe the risk factors of CHD. The results indicated that genotype of IL-6 gene promoter -597G/A polymorphism in 7 cases were GA and were GG in others, whereas no AA genotype had been found and no associations between polymorphism of IL-6 gene -597G/A, BMI and inflammatory factors were found. No differences had been found between the frequencies of IL-6 gene -572G/C genotypes and alleles in CHD and control group. However, significant difference was found between the G allele carrier (GG+GC) and non-G allele carrier (CC) of CHD and control group (p=0.0425). In the control group, median levels of systolic blood pressure of G allele carrier were significant higher than non-G allele carrier (p=0.02). Among all the subjects, median levels of BMI, hsCRP and systolic blood pressure in the group of G allele carrier were significantly higher than that in the group of non-G allele carrier, p values were 0.026, 0.022, 0.005 respectively. Multivariate logistic regression analysis showed that age, triglyceride, sex, high blood pressure, apoprotein C2, cholesterol and lipoprotein-a) were the risk factors for CHD, and apoprotein A1 was a protective factor. The G allele of IL-6 gene -572G/C has been not found to be a risk factor for CHD. It is concluded IL-6 gene -597G/A polymorphism is not correlated with the susceptibility to CHD; IL-6 gene -572G/C polymorphism may be correlated with the susceptibility to CHD in Han nationality of North China, the mechanisms may be related with the changes of BMI, hsCRP and blood pressure levels resulted from the polymorphism of IL-6 -572G/C.