Roh Lucienne, Braun Julia, Chiolero Arnaud, Bopp Matthias, Rohrmann Sabine, Faeh David
Institute of Social and Preventive Medicine (ISPM), University of Zurich, Hirschengraben 84, 8001 Zürich, Switzerland.
BMC Public Health. 2014 Apr 16;14:371. doi: 10.1186/1471-2458-14-371.
In contrast to obesity, information on the health risks of underweight is sparse. We examined the long-term association between underweight and mortality by considering factors possibly influencing this relationship.
We included 31,578 individuals aged 25-74 years, who participated in population based health studies between 1977 and 1993 and were followed-up for survival until 2008 by record linkage with the Swiss National Cohort (SNC). Body Mass Index (BMI) was calculated from measured (53% of study population) or self-reported height and weight. Underweight was defined as BMI < 18.5 kg/m2. Cox regression models were used to determine mortality Hazard Ratios (HR) of underweight vs. normal weight (BMI 18.5- < 25.0 kg/m2). Covariates were study, sex, smoking, healthy eating proxy, sports frequency, and educational level.
Underweight individuals represented 3.0% of the total study population (n = 945), and were mostly women (89.9%). Compared to normal weight, underweight was associated with increased all-cause mortality (HR: 1.37; 95% CI: 1.14-1.65). Increased risk was apparent in both sexes, regardless of smoking status, and mainly driven by excess death from external causes (HR: 3.18; 1.96-5.17), but not cancer, cardiovascular or respiratory diseases. The HR were 1.16 (0.88-1.53) in studies with measured BMI and 1.59 (1.24-2.05) with self-reported BMI.
The increased risk of dying of underweight people was mainly due to an increased mortality risk from external causes. Using self-reported BMI may lead to an overestimation of mortality risk associated with underweight.
与肥胖形成对比的是，关于体重过轻对健康风险的信息较为匮乏。我们通过考虑可能影响这种关系的因素，研究了体重过轻与死亡率之间的长期关联。
我们纳入了31578名年龄在25 - 74岁之间的个体，他们于1977年至1993年参与了基于人群的健康研究，并通过与瑞士国民队列（SNC）的记录链接随访至2008年以了解生存情况。体重指数（BMI）根据测量的身高和体重（占研究人群的53%）或自我报告的身高和体重计算得出。体重过轻定义为BMI＜18.5kg/m²。使用Cox回归模型确定体重过轻与正常体重（BMI 18.5 - ＜25.0kg/m²）相比的死亡率风险比（HR）。协变量包括研究、性别、吸烟、健康饮食指标、运动频率和教育水平。
体重过轻的个体占总研究人群的3.0%（n = 945），且大多为女性（89.9%）。与正常体重相比，体重过轻与全因死亡率增加相关（HR：1.37；95%CI：1.14 - 1.65）。无论吸烟状况如何，这种风险增加在两性中均很明显，且主要由外部原因导致的额外死亡驱动（HR：3.18；1.96 - 5.17），而非癌症、心血管或呼吸系统疾病。在使用测量BMI的研究中HR为1.16（0.88 - 1.53），在使用自我报告BMI的研究中HR为1.59（1.24 - 2.05）。
体重过轻人群死亡风险增加主要是由于外部原因导致的死亡风险增加。使用自我报告的BMI可能会高估与体重过轻相关的死亡风险。
