Wang Yun Feng, Tang Zhe, Guo Jin, Tao Li Xin, Liu Long, Li Hai Bin, Li Di Tian, Guo Xiu Hua, Yang Xing Hua
School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing 100069, China.
Xuan Wu Hospital, Capital Medical University, Beijing 100053, China.
Biomed Environ Sci. 2017 Feb;30(2):79-87. doi: 10.3967/bes2017.011.
To explore the association between body mass index (BMI) and all-cause mortality among the elderly in Beijing.
This analysis was based on the Beijing multidimensional longitudinal study of aging (BLSA), which included 2,090 subjects over 55 years old and was followed-up from 1992 to 2012. BMI-mortality curves were drawn to find the optimal BMI range with the lowest mortality. Cox proportional hazard models were used to obtain the hazard ratios (HRs) for BMI and BMI changes in the overall population and in specific stratified populations.
During follow-up, 1,164 deaths were recorded; BMI-mortality curve was U-shaped, with the lowest mortality at a BMI of approximately 25 kg/m2. After adjusting for gender, age, smoking, drinking and some pre-existing diseases, HRs for underweight, overweight and obesity compared with normal weight were 1.372 (95% CI: 1.154-1.631), 0.767 (95% CI: 0.666-0.884) and 0.871 (95% CI: 0.830-1.246), respectively. HR for BMI drop was 3.245 (95% CI: 0.824-12.772) in the underweight group and 1.892 (95% CI: 0.830-1.246) in the normal weight group, HR for BMI rise was 1.795 (95% CI: 1.243-2.591) in normal weight group and 1.962 (95% CI: 1.202-3.203) in the overweight group.
Keeping BMI in an overweight status and stable is related to a reduced mortality.
探讨北京老年人身体质量指数（BMI）与全因死亡率之间的关联。
本分析基于北京多维老龄化纵向研究（BLSA），该研究纳入了2090名55岁以上的受试者，随访时间为1992年至2012年。绘制BMI-死亡率曲线以找出死亡率最低的最佳BMI范围。使用Cox比例风险模型获得总体人群和特定分层人群中BMI及BMI变化的风险比（HRs）。
随访期间，记录到1164例死亡；BMI-死亡率曲线呈U形，BMI约为25kg/m²时死亡率最低。在调整性别、年龄、吸烟、饮酒和一些既往疾病后，与正常体重相比，体重过轻、超重和肥胖的HR分别为1.372（95%CI：1.154-1.631）、0.767（95%CI：0.666-0.884）和0.871（95%CI：0.830-1.246）。体重过轻组BMI下降的HR为3.245（95%CI：0.824-12.772），正常体重组为1.892（95%CI：0.830-1.246）；正常体重组BMI上升的HR为1.795（95%CI：1.243-2.591），超重组为1.962（95%CI：1.202-3.203）。
保持BMI处于超重状态且稳定与降低死亡率有关。
