McAuley Paul, Myers Jonathan, Abella Joshua, Froelicher Victor
Cardiology Division, VA Palo Alto Health Care System/Stanford University, Palo Alto, Calif 94304, USA.
Am J Med. 2007 Jun;120(6):518-24. doi: 10.1016/j.amjmed.2006.07.032.
The paradox of obesity in patients with heart failure (HF) also has been observed in non-HF veteran patients. Veterans had to have met military fitness requirements at the time of their enlistment. Therefore, we assessed the relation of body mass index (BMI) to mortality in a clinical cohort of non-HF veterans, adjusting for fitness.
After excluding HF patients (n=580), the study population comprised 6876 consecutive patients (mean age 58 [+/-11] years) referred for exercise testing. Patients were classified by BMI category: normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), or obese (BMI > or =30.0 kg/m2). The association between BMI, fitness, other clinical variables, and all-cause mortality was assessed by Cox proportional hazards analysis.
During a mean (+/-SD) follow-up of 7.5+/-4.5 years, a total of 1571 (23%) patients died. In a multivariate analysis including clinical, risk factor, and exercise test data, higher BMI was associated with better survival. Expressing the data by BMI category, obese patients were 22% less likely to die (relative risk [RR]=0.78, 95% confidence interval [CI], 0.69-0.90, P<.001) than patients of normal weight. After further adjustment for cardiorespiratory fitness (CRF), this relationship strengthened such that mortality risk for the obese category was 35% lower (RR=0.65, 95% CI, 0.57-0.76, P<.001), versus the normal weight category.
As has been observed in HF patients, obesity was associated with a substantially lower mortality risk in a clinical population of non-HF veterans. Higher CRF and obesity in later life may account for an obesity paradox in this population.
心力衰竭（HF）患者中的肥胖悖论在非HF退伍军人患者中也有观察到。退伍军人在入伍时必须符合军事体能要求。因此，我们在一个非HF退伍军人的临床队列中评估了体重指数（BMI）与死亡率的关系，并对体能进行了校正。
排除HF患者（n = 580）后，研究人群包括6876例连续接受运动测试的患者（平均年龄58 [±11]岁）。患者按BMI类别分类：正常体重（BMI 18.5 - 24.9 kg/m²）、超重（BMI 25.0 - 29.9 kg/m²）或肥胖（BMI≥30.0 kg/m²）。通过Cox比例风险分析评估BMI、体能、其他临床变量与全因死亡率之间的关联。
在平均（±标准差）7.5±4.5年的随访期间，共有1571例（23%）患者死亡。在包括临床、危险因素和运动测试数据的多变量分析中，较高的BMI与更好的生存率相关。按BMI类别表示数据，肥胖患者死亡的可能性比正常体重患者低22%（相对风险[RR]=0.78，95%置信区间[CI]，0.69 - 0.90，P<0.001）。在进一步校正心肺适能（CRF）后，这种关系得到加强，肥胖类别与正常体重类别相比，死亡风险降低35%（RR = 0.65，95% CI，0.57 - 0.76，P<0.001）。
正如在HF患者中观察到的那样，肥胖与非HF退伍军人临床人群中显著较低的死亡风险相关。晚年较高的CRF和肥胖可能解释了该人群中的肥胖悖论。
