Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.
Division of Cardiovascular Medicine, Howard University Hospital and School of Medicine, Washington, DC.
JACC Heart Fail. 2018 Mar;6(3):233-242. doi: 10.1016/j.jchf.2017.11.011. Epub 2018 Feb 7.
This study sought to evaluate the influence of race/ethnicity on the relationship between body mass index (BMI) and mortality in heart failure with preserved ejection fraction (HFpEF) and HF with reduced EF (HFrEF) patients.
Prior studies demonstrated an "obesity paradox" among overweight and obese patients, where they have a better HF prognosis than normal weight patients. Less is known about the relationship between BMI and mortality among diverse patients with HF, particularly given disparities in obesity and HF prevalence.
The authors used Get With The Guidelines-Heart Failure data to assess the relationship between BMI and in-hospital mortality by using logistic regression modeling. The authors assessed 30-day and 1-year rates of all-cause mortality following discharge by using Cox regression modeling.
A total of 39,647 patients with HF were included (32,434 [81.8%] white subjects; 3,809 [9.6%] black subjects; 1,928 [4.9%] Hispanic subjects; 544 [1.4%] Asian subjects; and 932 [2.3%] other subjects); 59.7% of subjects had HFpEF, and 30.7% were obese. More black and Hispanic patients had Class I or higher obesity (BMI ≥30 kg/m) than whites, Asians, or other racial/ethnic groups (p < 0.0001). Among subjects with HFpEF, higher BMI was associated with lower 30-day mortality, up to 30 kg/m with a small risk increase above 30 kg/m (BMI: 30 vs. 18.5 kg/m), hazard ratio (HR) of 0.63 (95% confidence interval [CI]: 0.54 to 0.73). A modest relationship was observed in HFrEF subjects (BMI: 30 vs. 18.5 kg/m; HR: 0.73; 95% CI: 0.60 to 0.89), with no risk increase above 30 kg/m. There were no significant interactions between BMI and race or ethnicity related to 30-day mortality (p > 0.05).
This work is one of the first suggesting the obesity paradox for 30-day mortality exists at all BMI levels in HFrEF but not in patients with HFpEF. Higher BMI was associated with lower 30-day mortality across racial/ethnic groups in a manner inconsistent with the J-shaped relationship noted for coronary artery disease. The differential slope of obesity and mortality among HFpEF and patients with HFrEF potentially suggests differing mechanistic factors, requiring further exploration.
本研究旨在评估种族/民族对射血分数保留的心力衰竭（HFpEF）和射血分数降低的心力衰竭（HFrEF）患者中体重指数（BMI）与死亡率之间关系的影响。
先前的研究表明，超重和肥胖患者存在“肥胖悖论”，即他们的心力衰竭预后优于正常体重患者。关于 BMI 与心力衰竭患者死亡率之间的关系，特别是考虑到肥胖和心力衰竭患病率的差异，了解较少。
作者使用 Get With The Guidelines-Heart Failure 数据，通过逻辑回归模型评估 BMI 与住院死亡率之间的关系。作者使用 Cox 回归模型评估出院后 30 天和 1 年全因死亡率。
共纳入 39647 例心力衰竭患者（32434 例[81.8%]为白人患者；3809 例[9.6%]为黑人患者；1928 例[4.9%]为西班牙裔患者；544 例[1.4%]为亚洲患者；932 例[2.3%]为其他种族/民族患者）；59.7%的患者为 HFpEF，30.7%为肥胖患者。与白人、亚洲人或其他种族/民族群体相比，更多的黑人和西班牙裔患者患有 I 类或更高等级的肥胖症（BMI≥30kg/m²）（p<0.0001）。在 HFpEF 患者中，较高的 BMI 与较低的 30 天死亡率相关，BMI 为 30kg/m²时死亡率最低，高于 30kg/m²时死亡率略有增加（BMI：30 与 18.5kg/m²；危险比[HR]：0.63[95%置信区间[CI]：0.54 至 0.73]）。在 HFrEF 患者中观察到适度的关系（BMI：30 与 18.5kg/m²；HR：0.73；95%CI：0.60 至 0.89），但 BMI 高于 30kg/m²时无风险增加。BMI 与种族或民族之间与 30 天死亡率无显著交互作用（p>0.05）。
这是第一项表明肥胖悖论在 HFrEF 患者的所有 BMI 水平上都存在 30 天死亡率的研究之一，但在 HFpEF 患者中则不然。较高的 BMI 与 30 天死亡率呈负相关，与冠心病的 J 形关系不一致。HFpEF 和 HFrEF 患者中肥胖症和死亡率的斜率差异可能表明存在不同的机制因素，需要进一步探讨。
