Study On The Relationship Between β₂-AR, ACE Genes Polymorphism And Essential Hypertension Complicated By Ischemic Cerebrovascular Disease

Objective: To investigate the association between polymorphisms of the -1023 region ofβ2-adrenoceptor(β2-AR/-1023) gene-G/A,angiotensin converting enzyme (ACE) gene insertion/deletion(I/D) and essential hypertension(EH) complicated by ischemic cerebrovascular disease(ICVD).Methods: We collected 345 subjects of EH-ICVD group, 315 subjects of EH without ICVD(EH-non-ICVD) group and 255 subjects of control group.β2-AR/-1023 gene-G/A were determined with the use of Polymerase Chain Reaction-Restriction Fragment Length Polymorphism(PCR-RFLP) methods,ACE gene-I/D polymorphisms were determined with the use of PCR,and polymorphic frequencies were compared in patients with EH-ICVD,EH-non-ICVD group and control. Information about prior exposure to various potential risk factors was also obtained. Chi-square test was used to compare difference of genotypes distribution among the three groups. The Hardy-Weinberg equilibrium was tested by Chi-square test of goodness of fit. Odds ratios for these comparisons of dangerous factors were calculated by Binary and Multinomial Logistic Regression.Results: 1. The frequencies of different geneotypes ofβ2-AR/-1023 and ACE were in agreement with Hardy-Weinberg equilibrium in our study(P>0.05).2. Chi-square test showed significant difference forβ2-AR-AA, AG and GG genotypes distribution in the three groups(χ2=11.834,P=0.019), and then Partitions ofχ2 method indicated thatβ2-AR-AA genotype frequencies in EH-ICVD group ( 12.5% ) were significantly higher than those in EH-non-ICVD group(7.0%)and Control group(5.5%) (χ2=10.298,P=0.001). The constituent ratio of ACE-II, ID, DD genotype was significantly different in the three groups(χ2=16.884,P=0.002), and then Partitions ofχ2 method showed that ACE–DD genotype frequencies in EH-ICVD group(20.9%) were significantly higher than those in EH-non-ICVD group(14.6%)and Control group(9.4%)(χ2=12.093,P=0.001). The 2 gene conjoint Analysis indicated significant difference of combined genotype frequencies in the three groups (χ2=27.814,P<0.001), furthermore, and Partitions ofχ2 method showed that AG/GG+II/ID combined genotype frequencies in EH-ICVD group(68.4%) were significantly lower than those in EH-non-ICVD group(79.7%)and Control group(85.9%)(χ2=24.073,P<0.001).3. Multinomial Logistic-regression Analysis indicated that Smoke,Cholesterol, Blood Pressure Level,Blood Pressure Period,β2-AR-AA genotype,ACE-DD genotype were risk factors for EH-ICVD.The odds ratios(OR) of theβ2-AR-AA genotype vs AG/GG and ACE-DD genotype vs II/ID for EH-ICVD were 1.854 (95%CI:1.041-3.301,P=0.036) and 1.590 (95%CI:1.019-2.481, P=0.041) after adjusting other confounding factors, respectively.Conclusion:β2-AR-AA and ACE-DD genotype may be the independent risk factors of hypertensive patients with ischemic cerebrovascular disease.