Klatsky Arthur L, Zhang Jasmine, Udaltsova Natalia, Li Yan, Tran H Nicole
Senior Consultant in Cardiology and an Adjunct Investigator in the Division of Research, Kaiser Permanente Medical Care Program in Oakland, CA.
High School Student in Orinda, CA.
Perm J. 2017;21:16-142. doi: 10.7812/TPP/16-142.
Controversy persists about optimal body weight. Many experts define "normal" (healthy) body mass index (BMI) as 18.5 to 24.9 kg/m, 25 to 29.9 kg/m as overweight, and 30 kg/m or greater as obese. Obesity is subdivided into 30 to 34.9 kg/m (Grade 1), 35 to 39.9 kg/m (Grade 2), and 40 kg/m and above (Grade 3). Studies consistently show higher mortality for underweight and Grade 2 or 3 obesity, but results conflict for the overweight category and Grade 1 obesity.
To study 30-year risk of death related to baseline BMI.
Retrospective cohort study in a multiracial population of 273,843 persons using logistic regression with 7 covariates (sex, age, race-ethnicity, education, marital status, smoking, alcohol intake).
Mortality risk by baseline BMI.
With average follow-up exceeding 30 years, there were 103,218 deaths: 41,215 attributed to cardiovascular causes and 62,003 to noncardiovascular causes. Odds ratios (and 95% confidence intervals) for all deaths in BMI categories, with a BMI of 18.5 to 24.9 kg/m as the referent, were BMI below 18.5 kg/m = 1.1 (1.0-2.0), BMI 25 to 29 kg/m = 1.1 (1.1-1.2), BMI 30 to 34 kg/m = 1.5 (1.4-1.5), BMI 35 to 39 kg/m = 2.1 (1.9-2.3), and BMI 40 kg/m or higher = 2.7 (2.4-3.0). Disparities existed regarding age, race/ethnicity, cause of death, and interval to death.
Compared with persons with BMI defined as normal, persons who were underweight, overweight, and obese were at increased risk of death over 30 years.
关于最佳体重的争议一直存在。许多专家将“正常”（健康）体重指数（BMI）定义为18.5至24.9千克/平方米，25至29.9千克/平方米为超重，30千克/平方米及以上为肥胖。肥胖又细分为30至34.9千克/平方米（1级）、35至39.9千克/平方米（2级）和40千克/平方米及以上（3级）。研究一致表明，体重过轻以及2级或3级肥胖者的死亡率较高，但超重类别和1级肥胖的研究结果存在冲突。
研究与基线BMI相关的30年死亡风险。
对273843名多族裔人群进行回顾性队列研究，采用包含7个协变量（性别、年龄、种族/族裔、教育程度、婚姻状况、吸烟、饮酒量）的逻辑回归分析。
根据基线BMI得出的死亡风险。
平均随访超过30年，共有103218人死亡：41215人死于心血管疾病，62003人死于非心血管疾病。以BMI为18.5至24.9千克/平方米作为参照，各BMI类别全因死亡的比值比（及95%置信区间）分别为：BMI低于18.5千克/平方米 = 1.1（1.0 - 2.0），BMI为25至29千克/平方米 = 1.1（1.1 - 1.2），BMI为30至34千克/平方米 = 1.5（1.4 - 1.5），BMI为35至39千克/平方米 = 2.1（1.9 - 2.3），BMI为40千克/平方米及以上 = 2.7（2.4 - 3.0）。在年龄、种族/族裔、死因和死亡间隔方面存在差异。
与BMI定义为正常的人相比，体重过轻、超重和肥胖的人在30年内死亡风险增加。
