Greenberg J A, Fontaine K, Allison D B
Department of Health and Nutrition Sciences, Brooklyn College of the City University of New York, Brooklyn, NY, USA.
Int J Obes (Lond). 2007 Sep;31(9):1449-55. doi: 10.1038/sj.ijo.0803615. Epub 2007 May 1.
A recent analysis concluded that there were fewer excess deaths attributable to obesity in the US population than previously believed. This analysis may not have fully corrected for two putative biases, the regression-dilution and the reverse-causation biases. It is not presently known whether correcting for these biases would increase estimates of excess deaths attributable to obesity.
All-cause mortality hazard ratios (HRs) for different body mass index (BMI) categories were calculated and adjusted for confounding factors, using data from the prospective Atherosclerosis Risk in Communities Study. The analysis was based on 12 457 individuals aged 51-70 years and 606 all-cause deaths during a 5.3-year follow-up. The HRs were corrected for the regression-dilution and reverse-causation biases, and compared with data from a previously published study to evaluate the effects of correcting for these putative biases on estimates of excess deaths attributable to obesity in the US population.
The uncorrected all-cause mortality HR for obesity (BMI>/=30) was 1.26 (95% confidence interval (95% CI)=1.01-1.58), using the 21-25 kg/m(2) as ideal-weight category. Correcting for regression dilution increased the HR to 1.46 (95% CI=1.17-1.83). Correcting for both putative biases increased it further to 2.70 (95% CI=1.31-5.57). Such increases in HRs are consonant with increases of several hundred percent in estimates of deaths attributable to obesity in the US.
Correcting for putative biases yielded increases in all-cause mortality HRs for obesity that correspond to substantial increases in estimates of excess deaths attributable to obesity in the US population.
最近的一项分析得出结论，美国人群中归因于肥胖的额外死亡人数比之前认为的要少。该分析可能未完全校正两种假定的偏差，即回归稀释偏差和反向因果偏差。目前尚不清楚校正这些偏差是否会增加归因于肥胖的额外死亡人数的估计值。
使用前瞻性社区动脉粥样硬化风险研究的数据，计算不同体重指数（BMI）类别的全因死亡率风险比（HRs），并对混杂因素进行校正。该分析基于12457名年龄在51 - 70岁之间的个体，在5.3年的随访期间有606例全因死亡。对HRs校正回归稀释偏差和反向因果偏差，并与先前发表的研究数据进行比较，以评估校正这些假定偏差对美国人群中归因于肥胖的额外死亡人数估计值的影响。
以21 - 25kg/m²作为理想体重类别，肥胖（BMI≥30）未经校正的全因死亡率HR为1.26（95%置信区间（95%CI）=1.01 - 1.58）。校正回归稀释后，HR增加到1.46（95%CI = 1.17 - 1.83）。校正两种假定偏差后，HR进一步增加到2.70（95%CI = 1.31 - 5.57）。HRs的这种增加与美国归因于肥胖的死亡人数估计值增加数百%相一致。
校正假定偏差导致肥胖的全因死亡率HRs增加，这与美国人群中归因于肥胖的额外死亡人数估计值的大幅增加相对应。
