Division of Cardiology, Department of Medicine, St Luke's-Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York, NY 10025, USA.
Am Heart J. 2013 Jul;166(1):127-33. doi: 10.1016/j.ahj.2013.03.027. Epub 2013 May 2.
The obesity paradox has been reported in several populations of patients with cardiovascular disease. Recent data have shown that physical fitness may attenuate the obesity paradox. Patients who undergo pharmacologic stress testing are known to have a higher risk of mortality than those who can exercise. The purpose of this study is to determine the interaction of obesity and exercise ability on survival among patients with a normal stress-rest single-photon emission computed tomography (SPECT).
A total of 5,203 (60 ± 13 years, male 37%) patients without a history of heart disease and a normal stress-rest SPECT between the years 1995 and 2010 were included in this analysis. Body mass index categories were defined according to the World Health Organization classification: normal weight, 18.5 to 24.9 kg/m(2); overweight, 25 to 29.9 kg/m(2); and obese, ≥30 kg/m(2). Patients were divided into 3 groups based on their ability to exercise: those who reached ≥6 METs on exercise, those who attained a level of <6 METs, and those who required pharmacologic stress. Patients in each of these fitness groups were further divided into 3 subgroups based on their body mass index.
There were 939 (18%) deaths during a mean follow-up of 8.1 ± 4.1 years, for an overall event rate of 2.3%/y. Both exercise to ≥6 METs and being obese were associated with lower mortality. Adjusted multivariate analysis using the obese high-fit patients as the reference showed a wide heterogeneity in annualized mortality rates according to exercise and weight status, with annualized event rates which varied from 0.6%/y in the obese subjects who were physically fit to 5.3%/y among healthy subjects who underwent pharmacologic stress testing (P < .001).
Stress mode and body weight impacted long-term survival in patients with a normal stress SPECT. The benefit of being physically fit was evident in all weight groups, as was the adverse effect of being unable to exercise. However, with regard to body weight, there was a paradoxical survival advantage for those patients who were overweight and obese, regardless of their exercise ability.
肥胖悖论在多种心血管疾病患者群体中均有报道。最近的数据显示，身体机能可能会减弱肥胖悖论的影响。接受药物负荷试验的患者其死亡率高于可运动患者。本研究的目的是确定肥胖与运动能力在静息单光子发射计算机断层扫描（SPECT）正常的患者中的生存相互作用。
本研究共纳入了 5203 名（60 ± 13 岁，男性占 37%）无心脏病史且于 1995 年至 2010 年间行静息 SPECT 的患者。根据世界卫生组织的分类，将体重指数分为以下几类：正常体重，18.5 至 24.9kg/m²；超重，25 至 29.9kg/m²；肥胖，≥30kg/m²。根据运动能力，患者分为 3 组：达到≥6 METs 的运动组、达到<6 METs 的运动组和需要药物负荷的运动组。在这些运动组中，根据体重指数进一步分为 3 个亚组。
在平均 8.1 ± 4.1 年的随访期间，共有 939 名（18%）患者死亡，总体年死亡率为 2.3%。达到≥6 METs 的运动和肥胖均与较低的死亡率相关。使用肥胖高功能组作为参考，进行多变量调整后分析显示，根据运动和体重状态，年化死亡率存在广泛的异质性，运动能力正常的肥胖患者年化死亡率为 0.6%，而健康患者行药物负荷测试的年化死亡率为 5.3%（P<0.001）。
静息 SPECT 正常的患者的应激模式和体重会影响长期生存。在所有体重组中，身体机能良好都有益，而无法运动则有害。然而，就体重而言，超重和肥胖患者无论运动能力如何，均存在生存优势的悖论。
