The Contribution of Obesity to International Differences in Longevity

描述（由申请人提供）：本研究的主要目的是确定肥胖对国际寿命差异的影响。美国成年人的肥胖患病率高于欧洲、北美或东亚任何其他国家的成年人。与此同时，美国人的预期寿命已经低于大多数其他经合组织国家，2008年在世界上排名第32位。美国人在健康和寿命方面处于劣势的主要原因之一是其高水平的肥胖。评估肥胖对国际寿命差异的贡献的一个关键输入是与不同肥胖水平相关的个人水平死亡风险集。该项目将确定一系列与肥胖有关的死亡率风险，这些风险应用于国际和跨时期比较。我们通过明确引入与当前肥胖相关的死亡风险所依赖的另外两个因素来做到这一点：一个人的肥胖史和他或她的吸烟状况。早期研究中对肥胖史的遗漏导致了对当前肥胖影响的有偏见的估计。非吸烟者因肥胖而死亡的风险高于吸烟者，因此，吸烟严重的国家的肥胖风险应该较低。我们将应用这些肥胖风险来计算人群归因风险以及肥胖对生存和寿命的影响。我们工作的一个重要成果将是解释肥胖对死亡率的估计影响大幅下降的原因。此外，我们将开发一种新的间接方法来估计肥胖对寿命国际差异的贡献，通过建立以前的方法来估计吸烟导致的死亡率。肥胖的流行病学和人口学研究将从澄清与肥胖相关的死亡风险中获益良多。这样的澄清也将有助于改善美国和其他地方的死亡率预测。未来死亡率的不确定性是社会保障信托基金的财政平衡最敏感的一个因素。这个项目对改进预测的贡献是通过明确地将肥胖历史纳入风险分析而增强的，因为这些历史在实际死亡情况之前就已经被揭示出来了。

DESCRIPTION (provided by applicant): The primary objective of this research is to identify the contribution of obesity to international differences in longevity. Adults in the United States have a higher prevalence of obesity than adults in any other country in Europe, North America, or East Asia. At the same time, life expectancy in the United States has fallen below that of most other OECD countries and ranked 32nd in the world in 2008. One of the prime candidates to account for the US disadvantage in health and longevity is its high level of obesity. A key input to evaluating the contribution of obesity to international differences in longevity is the set of individual-level mortality risks associated with different levels of obesity. This project will identify the set of mortality risks associated with obesity that should be used in international and intertemporal comparisons. We do so by explicitly introducing two other factors on which the mortality risks associated with current obesity depend: an individual's history of obesity and his or her smoking status. The omission of obesity histories from earlier studies has led to biased estimates of the effects of current obesity. Non-smokers show a higher mortality risk from obesity than smokers, so that countries that smoke heavily should be expected to have lower risks from obesity. We will apply these sets of obesity risks to calculate population attributable risks and obesity's implications for survivorship and longevity. An important product of our work will be an explanation of the large declines that have been observed in the estimated effect of obesity on mortality. In addition, we will develop a new indirect approach to estimating the contribution of obesity to international differences in longevity by building on previous methods developed to estimate smoking-attributable mortality. Epidemiologic and demographic studies of obesity would benefit greatly from a clarification of the mortality risks associated with obesity. Such a clarification would also contribute to improved projections of mortality in the US and elsewhere. Uncertainty about future of mortality is the single factor to which fiscal balances in the Social Security Trust Fund are most sensitive. The contribution of this project to improved projections is enhanced by its explicit incorporation of obesity histories into the risk analysis, since these histories are revealed well in advance of actual mortality conditions. PUBLIC HEALTH RELEVANCE: The United States has the highest prevalence of obesity and one of the lowest life expectancies among developed nations. The objective of this research is to identify the contribution of obesity to international differences in longevity. Results will lead to improved mortality projections and a clearer understanding of how obesity is influencing national mortality profiles.