Polymorphisms within angiotensin II receptor type 1 gene associated with essential hypertension in Chinese Hani and Yi minorities

Introduction: Angiotensin II receptor type 1 mediates the major cardiovascular effects of angiotensin II to regulate blood pressure. Polymorphisms of angiotensin II receptor type 1 are associated with essential hypertension, but the results are inconsistent and conflicting. The aim of the present study is to assess the association between angiotensin II receptor type 1 polymorphisms and essential hypertension risk in Chinese Hani and Yi minorities.

Methods: This study recruited 692 unrelated Chinese Hani subjects (case vs. control = 346:346) and 615 unrelated Chinese Yi subjects (case vs. control = 303:312). Twelve selected single nucleotide polymorphisms in the angiotensin II receptor type 1 gene were genotyped using a polymerase chain reaction-restriction fragment length polymorphism method.

Results: Statistical analysis indicated that the GC+CC genotype of rs387967 was significantly associated with the decreased susceptibility to essential hypertension compared with GG in a Yi population (odds ratio = 0.58, 95% confidence intervals 0.41-0.83, P = 0.003). Allele C was a protective allele for essential hypertension (odds ratio = 0.78, 95% confidence intervals 0.61-0.99, P = 0.040). This association was confirmed respectively by comparing systolic blood pressure and diastolic blood pressure between different genotypes and between different alleles, which indicated that the genotype (GC+CC) had a tendency of lower systolic blood pressure and diastolic blood pressure than GG (PSBP = 3.716 × 10(-4), PDBP = 1.187 × 10(-3)); Carriers with C had lower systolic blood pressure and diastolic blood pressure (PSBP = 7.301 × 10(-3), PDBP = 9.142 × 10(-4)). Another single nucleotide polymorphism (rs2638360) was analysed in a Hani minority, then replicated in a Yi minority. The C allele showed a consistent risk trend for essential hypertension in two independent populations (Hani: odds ratio = 1.74, 95% confidence intervals 1.01-2.99, P = 0.046; Yi: odds ratio = 1.27, 95% confidence intervals 0.82-1.96, P = 0.277). Meta-analysis revealed that the C allele could significantly increase the risk of essential hypertension (odds ratio = 1.44, 95% confidence intervals 1.02-2.02, P = 0.037).

Conclusion: Our findings suggest that rs387967 is associated with the susceptibility to essential hypertension in a Yi population and the tendency was replicated in systolic blood pressure and diastolic blood pressure detection. Meta-analysis revealed that C allele of rs2638360 could significantly increase the risk of essential hypertension. The two single nucleotide polymorphisms maybe play a role in the pathology of essential hypertension.