Objective: To investigate the relationship between body mass index (BMI) and all-cause mortality in hypertensive population. Methods: All participants were selected from a prospective cohort study based on a rural population from Henan province, China. Cox proportional hazards regression models were used to estimate the associations of different levels of BMI stratification with all-cause mortality. Restricted cubic spline models were used to detect the dose-response relation. Results: Among the 5 461 hypertensive patients, a total of 31 048.38 person-years follow-up was conducted. The median of follow-up time was 6 years, and 589 deaths occurred during the follow-up period. Compared to normal weight group (18.5 kg/m(2)<BMI<24.0 kg/m(2)) the multivariate-adjusted hazard ratios for all-cause mortality associated with BMI levels (<18.5 kg/m(2), 24-28 kg/m(2), and ≥28 kg/m(2)) were 0.83 (95%CI: 0.37-1.87), 0.81 (95%CI: 0.67-0.97), and 0.72 (95%CI: 0.56-0.91), respectively. The dose-response analysis showed a nonlinear, reverse "S" shaped relationship (non-linearity P<0.001). Conclusion: Overweight or obese might have a protective effect on all-cause mortality in hypertensive population, which supports the "obesity paradox" phenomenon.
目的： 探讨高血压队列人群中BMI和全死因死亡风险的关系。 方法： 研究对象为河南省某农村地区高血压队列人群，应用Cox风险比例回归模型计算基线时不同BMI水平人群随访期间的全死因死亡比例HR值及其95%CI，并采用限制性立方样条模型拟合BMI与全死因死亡风险的剂量-反应关系。 结果： 5 461名高血压队列人群累积随访31 048.38人年，平均随访6年，随访期间死亡589人。控制潜在的混杂因素后，以基线正常体重组（18.5 kg/m(2)<BMI<24.0 kg/m(2)）为参照，低体重组（BMI<18.5 kg/m(2)）、超重组（24.0 kg/m(2)<BMI<28.0 kg/m(2)）和肥胖组（BMI≥28 kg/m(2)）人群发生死亡的HR值（95%CI）分别为0.83（0.37~1.87）、0.81（0.67~0.97）和0.72（0.56~0.91）。限制性立方样条模型分析结果显示，在高血压队列人群中，基线BMI和全死因死亡风险关联强度呈现倒"S"形非线性剂量反应关系（非线性检验P<0.001）。 结论： 超重和肥胖可能是高血压人群死亡风险的保护因素，与"肥胖悖论"一致。.
Keywords: Body mass index; Hypertension; Mortality; Obesity paradox.