Department of Sociology, Ohio State University, Columbus, OH, USA.
Department of Preventive Medicine and Population Health, University of Texas Medical Branch, Galveston, Texas, USA.
Biodemography Soc Biol. 2020 Jan-Mar;66(1):50-68. doi: 10.1080/19485565.2020.1821597.
A key uncertainty in the obesity-mortality association continues to be how this association changes over the life course. Prior studies tend to rely on cross-sectional design with static weight status taken at the time of the survey. This study tracks a cohort of individuals and employs lifelong body mass index information from the Framingham Heart Study original cohort (1948-2010). We focus on respondents who were younger than age 45 at time of their first survey ( = 2,176) and evaluate how the mortality risk associated with obesity changes over three age groups (below 45, 45-59, and 60 and above) and how population compositions may contribute to this pattern. We find the hazard ratio associated with obesity compared to normal weight decreases over three age groups, but this pattern is influenced by different ages of onset of obesity, inconsistency in the reference group (normal weight) over ages, and mortality selection effects. These factors explain away the decreasing effect of obesity (with onset before age 45) on mortality up to age 60; after age 60, the detrimental effect still declines, but to a much less degree. Later onset of obesity, however, is not significantly associated with excess mortality risks after age 60.
肥胖与死亡率之间的关系存在一个关键的不确定性，即这种关系在整个生命过程中是如何变化的。先前的研究往往依赖于横断面设计，即在调查时采用静态体重状况。本研究跟踪了一组个体，并利用弗雷明汉心脏研究原始队列（1948-2010 年）的终身体重指数信息。我们关注的是首次调查时年龄小于 45 岁的受访者（=2176），并评估肥胖相关的死亡率风险如何随三个年龄组（45 岁以下、45-59 岁和 60 岁及以上）而变化，以及人群构成如何对此模式产生影响。我们发现，与正常体重相比，肥胖相关的风险比在三个年龄组中逐渐降低，但这种模式受到肥胖起始年龄不同、参照组（正常体重）在不同年龄段的不一致性以及死亡率选择效应的影响。这些因素消除了肥胖（起始年龄小于 45 岁）对 60 岁前死亡率的降低作用；60 岁以后，有害影响仍在下降，但程度要小得多。然而，肥胖的起始年龄较晚，与 60 岁以后的超额死亡风险并无显著关联。
