Hypertensive patients from two rural Chinese counties respond differently to benazepril: the Anhui Hypertension Health Care Study

Heart rate–corrected QT interval duration is significantly associated with blood pressure in Chinese hypertensives

INTRODUCTION

Many studies demonstrated that a prolonged heart rate-corrected QT interval (QTc) increases the risk of malignant ventricular arrhythmias and sudden death.

METHODS

We measured the electrocardiogram and blood pressure of 1480 hypertensive patients and assessed the relationship between the length of QTc and blood pressure.

RESULTS

The mean QTc is longer in female than in male participants. There was a positive association between QTc and blood pressure in both men and women. The estimated increase in systolic and diastolic blood pressure for each 100-millisecond increase in QTc was 6.4 and 5.0 mm Hg in men and 3.7 and 2.5 mm Hg in women, respectively.

CONCLUSION

Our study demonstrated a significant positive relationship between the QTc interval and baseline blood pressure in a Chinese hypertensive population.

Beta2 adrenergic receptor gene Arg16Gly polymorphism is associated with therapeutic efficacy of benazepril on essential hypertension in Chinese

BACKGROUND

There is considerable variability in individual response to antihypertensive agents. The reason for this is not known, but may be related to individual genetic variability. This study examined whether the therapeutic efficacy of benazepril on essential hypertension is modified by beta2 adrenergic receptor gene (ADRB2) Arg16Gly (R16G) polymorphism.

METHODS AND RESULTS

We conducted a family-based study of 321 and 610 hypertensive subjects from Yuexi and Huoqiu Counties of Anhui, China, respectively. Both systolic and diastolic blood pressures (SBP and DBP) before and after a 15-day benazepril treatment were measured. ADRB2 R16G genotypes were determined for all subjects. ADRB2 G16 allele frequency was found to be 41.0% and. 47.4% in Huoqiu and Yuexi, respectively. In Yuexi family-based association test (FBAT) revealed that the G16 allele was associated with a greater DBP decrease in response to a 15-day benazepril treatment (Z = 2.12, P = 0.03), and the data were consistent with a dominant inheritance model. A similar trend was observed in Huoqiu Chinese, but the magnitudes of effects were smaller and did not reach statistical significance. The FBAT results were further confirmed by using a generalized estimating equation model.

CONCLUSION

Our family-based study provided the first evidence that ADRB2 R16G polymorphism may play an important role in DBP response to benazepril treatment, although the magnitude of the effect appears to be modified by other risk factors such as plasma lipid and glucose profiles.

D919G polymorphism of methionine synthase gene is associated with blood pressure response to benazepril in Chinese hypertensive patients

Individual variation in drug response is considered to have multiple origins arising from interactions among susceptible genes and environmental factors. A total of 726 hypertensive patients who took benazepril 10 mg once a day for 15 days and their families from Huoqiu county of Anhui Province, China, were used to study the association between D919G polymorphism of methionine synthase (MTR) gene and the antihypertensive effect of this angiotensin-converting enzyme inhibitor. Compared to the 919D allele, both population-based ( P=0.010) and family-based association tests (additive model P=0.018, dominant model P=0.025) demonstrated that the 919G allele was associated with a significantly less diastolic blood pressure reduction. No significant association was found between the extent of systolic blood pressure reduction and benazepril therapy. Our finding suggests that the D919G polymorphism of the MTR gene may be a useful genetic marker to predict the antihypertensive effect of short-term benazepril therapy in hypertensive patients of Anhui Province, China.