Division of Epidemiology, Tohoku University School of Public Health, Graduate School of Medicine, Sendai, Miyagi, Japan.
Int J Obes (Lond). 2019 Nov;43(11):2254-2263. doi: 10.1038/s41366-019-0359-3. Epub 2019 Apr 2.
The relationship between body mass index (BMI) and disability-free survival (DFS) remains unclear.
We conducted a 10-year prospective cohort study of 12,666 Japanese individuals aged ≥ 65 y. Information on BMI and lifestyle factors was collected via a questionnaire in 2006. Functional disability data were retrieved from the public Long-term Care Insurance database. Subjects were divided into seven groups according to BMI (<19, 19-21, 21-23, 23-25, 25-27, 27-29 and ≥29). Fiftieth percentile differences (PDs) and 95% confidence intervals (CIs) in the DFS period (differences of period until the first 50% of the composite outcome (disability or death) occurred in each of the BMI groups) were calculated using the Laplace regression model.
There was a U-shaped relationship between BMI and the risk of incident composite outcome, with a BMI nadir of 25-27. Based on BMI 25-27 as a reference, the 50th PDs (95% CIs) (in months) in age at disability or death (median DFS) were -20.8 (-26.4, -15.2) (P < 0.001) months for BMI <19, -13.5 (-18.2, -8.7) (P < 0.001) months for BMI 19-21, -9.8 (-14.2, -5.4) (P < 0.001) months for BMI 21-23, -2.9 (-7.5, 1.7) (P = 0.21) months for BMI 23-25, -2.7 (-8.4, 2.9) (P = 0.34) months for BMI 27-29, and -11.5 (-19.6, -3.5) (P = 0.005) months for BMI ≥ 29. These relationships did not differ by sex.
Older individuals with a BMI of <23 or ≥29 have a significantly shorter DFS period than those with a BMI of 25-27. It is suggested that the optimal BMI range for maximization of disability-free life expectancy in the elderly population is 23-29.
体重指数（BMI）与无残疾生存（DFS）之间的关系仍不清楚。
我们对 12666 名年龄≥65 岁的日本个体进行了一项为期 10 年的前瞻性队列研究。2006 年通过问卷收集 BMI 和生活方式因素的信息。从公共长期护理保险数据库中检索功能障碍数据。根据 BMI（<19、19-21、21-23、23-25、25-27、27-29 和≥29）将受试者分为七组。使用拉普拉斯回归模型计算 DFS 期间（每个 BMI 组中复合结局（残疾或死亡）发生的前 50%的差异）的第 50 个百分点差异（PD）和 95%置信区间（CI）。
BMI 与发生复合结局的风险之间存在 U 型关系，BMI 最低点为 25-27。以 BMI 25-27 为参考，年龄残疾或死亡时（DFS 中位数）的第 50 个 PD（95%CI）（以月为单位）分别为 BMI<19 时的-20.8（-26.4，-15.2）（P<0.001）个月，BMI 19-21 时的-13.5（-18.2，-8.7）（P<0.001）个月，BMI 21-23 时的-9.8（-14.2，-5.4）（P<0.001）个月，BMI 23-25 时的-2.9（-7.5，1.7）（P=0.21）个月，BMI 23-25 时的-2.7（-8.4，2.9）（P=0.34）个月，BMI 27-29 时的-11.5（-19.6，-3.5）（P=0.005）个月，BMI≥29 时的-11.5（-19.6，-3.5）（P=0.005）个月。这些关系不因性别而异。
与 BMI 25-27 的个体相比，BMI<23 或≥29 的老年人 DFS 期明显缩短。这表明，最大化老年人群无残疾预期寿命的最佳 BMI 范围为 23-29。
