我国成年人体质量指数及动态变化对高血压发病的影响

The Effects of Body Mass Index and its Dynamic Shift on Hypertension in Chinese Adults

背景国内外很多横断面研究表明体质量指数(BMI)与高血压发病之间存在相关关系,但国内有关BMI的动态变化与高血压发病危险之间关系的随访性研究较少。目的探讨我国成年人基线BMI及随访9年BMI水平的动态变化与高血压发病的关系。方法利用中美合作课题"中国健康与营养调查"1997年和2006年的追踪数据,对在1997年调查时不是高血压的20～65岁成年对象3737人的身高、体质量和血压等数据进行分析。应用广义线性模型估计RR,应用似然比检验腹部肥胖对全身性肥胖与高血压发病关系的交互作用。结果研究对象随访9年的高血压标准化率为16.2%,男性高于女性,高血压发病率随基线BMI水平的增加呈线性增加趋势(P<0.01);以基线体质量正常组为参照组,调整基线年龄、城乡、吸烟、饮酒、受教育程度后,基线超重和肥胖人群高血压发病的RR值呈线性增加(男性RR超重比正常=1.6,95%CI1.3～2.0,RR肥胖比正常=2.3,95%CI1.3～3.2;女性,RR超重比正常=1.8,95%CI1.4～2.2,RR肥胖比正常=2.0,95%CI1.5～2.8)。BMI水平的动态变化显示,两次测量BMI水平均为肥胖者高血压发病危险性是两次BMI值均正常的5.4倍;BMI水平的动态增加(从超重变为肥胖、从正常变为超重或肥胖)显著增加研究对象患高血压的危险(P<0.01)。结论 BMI是高血压发病的一个独立危险因素,动态监测BMI的变化可以有效预测高血压发病的危险。

Background Extensive cross-sectional studies have shown the correlation between body mass index （BMI） and hypertension. However,there were few prospective studies focusing on causal association between BMI level and hypertension among Chinese population. Objective To examine the association between general overweight/obesity accessed by BMI and 9-year cumulative incidence of hypertension and to explore the effect of dynamic changes in weight status on 9-year incidence of hypertension. Methods We used data from the years in 1997 and 2006 of a longitudinal study,China health and nutrition survey （CHNS）,analyzed the height,weight and blood pressure of 3737 adults aged from 20 to 65 years without hypertension in 1997. Generalized linear model was used to estimate the RR and likelihood ratio test to test the homogeneity of RR across the strata of abdominal obesity. Results The nine-year standardized cumulative incidence of hypertension was 16.2%. With normal baseline BMI （24 kg/m2） as the control group and adjusting for baseline age and other confounders,RR of hypertension associated with overweight/obese increased linearly on the logarithm scale （men：RRoverweight vs normal 1.6,95% CI 1.3-2.0,RRobesity vs normal=2.3,95% CI 1.3-3.2; women：RRoverweight vs normal=1.8,95% CI 1.4-2.2,RRobesity vs normal=2.0,95% CI 1.5-2.8）. On the other hand,the 9-year risk of developing hypertension in adults with obesity was 4.4 times higher than that in adults with normal BMI level. Dynamic increase in BMI level,from overweight to obesity,or from normal to overweight/obesity,significantly increased the risk of developing hypertension （P0.01）. Conclusion BMI prospectively appeared to be an independent risk factor for hypertension. Dynamically monitoring BMI could target vulnerable population. Interventions for decreasing weight or controlling weight-gain could control the epidemic of hypertension and other cardiovascular diseases effectively.