中文摘要：

ObjectiveTo 探索在身体团索引(BMI ) 和所有原因死亡之间的协会在之中在分析基于的 Beijing.MethodsThis 老老化(BLSA ) 的北京多维的纵的学习，它超过 55 岁包括了 2,090 个题目并且从 1992 ～ 2012 是跟随起来的。BMI 死亡曲线被拉与最低死亡发现最佳的 BMI 范围。比例的危险建模的考克斯被用来在全面人口并且在特定的成层的 populations.ResultsDuring 后续为 BMI 和 BMI 变化获得危险比率(HR ) ， 1,164 死亡被记录；BMI 死亡曲线是 U 字形的，与在约 25 kg/m ² 的 BMI 的最低死亡。在为性调整以后，变老，吸烟，喝并且与正常重量相比的一些先存在的疾病，为不足的重量的 HR，过重和肥胖是 1.372 (95% CI：1.154-1.631 ) ， 0.767 (95% CI：0.666-0.884 ) 并且 0.871 (95% CI：0.830-1.246 ) 分别地。为 BMI 落下的 HR 是 3.245 (95% CI：0.824-12.772 ) 在不足的重量组并且 1.892 (95% CI：0.830-1.246 ) 在正常重量组，，为 BMI 上升的 HR 是 1.795 (95% CI：1.243-2.591 ) 在正常重量组并且 1.962 (95% CI：1.202-3.203 ) 在超重 group.ConclusionKeeping，在超重地位和马厩的 BMI 与减少的死亡有关。

英文摘要：

Objective To explore the association between body mass index （BMI） and all-cause mortality among the elderly in Beijing. Methods 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. Results During follow-up, 2,264 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 2.372 （95% C/： 2.254-2.632）, 0.767 （95% CI： 0.666-0.884） and 0.872 （95% CI： 0.830-1.246）, respectively. HR for BMI drop was 3.245 （95% CI： 0.824-22.772） in the underweight group and 1.892 （95% C/： 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 2.962 （95% CI： 2.202-3.203） in the overweight group. Conclusion Keeping BMI in an overweight status and stable is related to a reduced mortality