Lawlor Debbie A, Hart Carole L, Hole David J, Davey Smith George
Department of Social Medicine, University of Bristol, Canynge Hall, Whiteladies Road, Bristol BS8 2PR, UK.
Obesity (Silver Spring). 2006 Dec;14(12):2294-304. doi: 10.1038/oby.2006.269.
To examine the effect of reverse causality and confounding on the association of BMI with all-cause and cause-specific mortality.
Data from two large prospective studies were used. One (a community-based cohort) included 8327 women and 7017 men who resided in two Scottish towns at the time of the baseline assessment in 1972-1976; the other (an occupational cohort) included 4016 men working in the central belt of Scotland at the time of the baseline assessment in 1970-1973. Participants in both cohorts were ages 45 to 64 years at baseline; the follow-up period was 28 to 34 years.
In age-adjusted analyses that did not take account of reverse causality or smoking, there was no association between being overweight (BMI 25 to <30 kg/m(2)) and mortality, and weak to modest associations between obesity (BMI > or =30 kg/m(2)) and mortality. There was a strong association between smoking and lower BMI in women and men in both cohorts (all p < 0.0001). Among never-smokers and with the first 5 years of deaths removed, overweight was associated with an increase in all-cause mortality (relative risk ranging from 1.12 to 1.38), and obesity was associated with a doubling of risk in men in both cohorts (relative risk, 2.10 and 1.96, respectively) and a 60% increase in women (relative risk, 1.56). In both never-smokers and current smokers, being overweight or obese was associated with important increases in the risk of cardiovascular disease.
These findings demonstrate that with appropriate control for smoking and reverse causality, both overweight and obesity are associated with important increases in all-cause and cause-specific mortality, and in particular with cardiovascular disease mortality.
探讨反向因果关系和混杂因素对体重指数（BMI）与全因死亡率及特定病因死亡率之间关联的影响。
使用了两项大型前瞻性研究的数据。一项（基于社区的队列研究）纳入了1972 - 1976年基线评估时居住在苏格兰两个城镇的8327名女性和7017名男性；另一项（职业队列研究）纳入了1970 - 1973年基线评估时在苏格兰中部地区工作的4016名男性。两个队列的参与者在基线时年龄均为45至64岁；随访期为28至34年。
在未考虑反向因果关系或吸烟因素的年龄调整分析中，超重（BMI为25至<30 kg/m²）与死亡率之间无关联，肥胖（BMI≥30 kg/m²）与死亡率之间存在弱至中等程度的关联。在两个队列的男性和女性中，吸烟与较低的BMI之间均存在强关联（所有p<0.0001）。在从不吸烟者中，并去除前5年的死亡病例后，超重与全因死亡率增加相关（相对风险范围为1.12至1.38），肥胖在两个队列的男性中使风险加倍（相对风险分别为2.10和1.96），在女性中使风险增加60%（相对风险为1.56）。在从不吸烟者和当前吸烟者中，超重或肥胖均与心血管疾病风险的显著增加相关。
这些发现表明，通过对吸烟和反向因果关系进行适当控制，超重和肥胖均与全因死亡率及特定病因死亡率的显著增加相关，尤其是与心血管疾病死亡率相关。
