Division of Cardiology, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA.
Am J Med. 2011 Oct;124(10):924-30. doi: 10.1016/j.amjmed.2011.04.018. Epub 2011 Jul 26.
An "obesity paradox," in which overweight and obese individuals with established cardiovascular disease have a better prognosis than normal weight subjects, has been reported in a number of clinical cohorts, but little is known about the effects of weight loss on the obesity paradox and its association with health outcomes.
Weight was determined in 3834 men at the time of a clinically referred exercise test and again during a clinical evaluation a mean of 7 years later. The associations among weight changes, baseline fitness, and other risk markers with cardiovascular and all-cause mortality were determined by Cox proportional hazards analysis.
During the follow-up period, 314 subjects died (72 of cardiovascular causes). In a multivariate analysis (including baseline weight, weight change, exercise capacity, and cardiovascular disease), weight gain was associated with lower mortality and weight loss was associated with higher mortality (4% higher per pound lost per year, P<.001) compared with stable weight. For all-cause mortality, the relative risks for the no change, weight gain, and weight loss groups were 1.0 (referent), 0.64 (95% confidence interval, 0.50-0.83), and 1.49 (95% confidence interval, 1.17-1.89), respectively (P<.001). Those who died and exhibited weight loss had a significantly higher prevalence of deaths due to cancer and cardiovascular causes.
Weight loss was related to higher mortality and weight gain was related to lower mortality when compared with stable weight. The obesity paradox in our sample is explained in part by a combination of non-volitional weight loss related to occult disease and a protective effect of weight gain.
在许多临床队列中，已经报道了一种“肥胖悖论”，即患有既定心血管疾病的超重和肥胖个体比正常体重个体预后更好，但对于减肥对肥胖悖论的影响及其与健康结果的关系知之甚少。
在临床推荐的运动测试时，对 3834 名男性进行了体重测定，并在平均 7 年后的临床评估中再次进行了体重测定。通过 Cox 比例风险分析确定体重变化、基线健康状况和其他风险标志物与心血管和全因死亡率之间的关联。
在随访期间，314 名受试者死亡（72 例心血管原因）。在多变量分析（包括基线体重、体重变化、运动能力和心血管疾病）中，与稳定体重相比，体重增加与较低的死亡率相关，而体重减轻与较高的死亡率相关（每年每磅减轻 4%，P<.001）。对于全因死亡率，无变化、体重增加和体重减轻组的相对风险分别为 1.0（参照）、0.64（95%置信区间，0.50-0.83）和 1.49（95%置信区间，0.17-0.83）。与稳定体重相比，那些体重减轻并发生死亡的患者因癌症和心血管原因导致死亡的比例明显更高。
与稳定体重相比，体重减轻与较高的死亡率相关，而体重增加与较低的死亡率相关。在我们的样本中，肥胖悖论部分可以通过与隐匿性疾病相关的非自愿性体重减轻和体重增加的保护作用来解释。
