Objective    To explore the relationship of interleukin-6 (IL-6) gene polymorphisms and its serum level with essential hypertension (EH) in Chinese Hans population and investigate the effect of IL-6 gene polymorphisms on serum IL-6 level.     Methods    The polymorphisms of IL-6 gene

-597 G/A

- 572 C/G and  174 G/C

were checked in 191 EH patients and 197 control subjects by PCR-RELP. Meanwhile their serum IL-6 level was determined by ELISA.     Results    Only -597 GG genotype and -174 GG genotype of IL-6 gene was found in the test population. There was significant difference in frequencies of - 572 genotype and allele between 2 groups. -572 CG+GG genotype and G allele were more frequent in patients than in controls (P0.05

P0.01). Compared to CC genotype，relative risk for hypertension were 1.68 (95%CI：1.12~2.53，P0.05) for -572 CG + GG genotype. EH group showed significantly higher serum level of IL-6 than control group [ (15.41±8.09) pg/ml vs (4.68±2.90) pg/ml，P0.01]. Serum IL-6 level of patients with -572 CG +GG genotype was higher than that of -572 CC genotype (P0.05)

and so the systolic blood pressure level (P0.05).     Conclusion    No IL-6 gene -597 G/A and -174 G/C polymorphisms is seen in our study. IL-6 gene -572 C/G polymorphism may be one of genetic risk factors for EH and it may increase the risk of EH by enhancing the IL-6 expression.