BMI, Nutrition, Inflammation and Heart Failure Outcomes

心源性恶病质是心力衰竭（HF）患者发病率和死亡率的独立危险因素。相比之下，最近有报道称肥胖与发病率和死亡率的降低有关。超重和肥胖合并心衰患者的预后出乎意料地好，这一发现与我们目前对肥胖和心衰之间关系的理解形成了对比，也与建议这些患者应该减肥的观点相冲突。这两组患者之间结果差异的生物行为机制尚不清楚。营养摄入是体重的主要因素，也可能在影响心衰结局方面发挥关键作用。促炎细胞因子作为肥胖和HF的全身炎症反应的一部分释放，影响食欲、食物摄入、身体组成、心肌功能、血管上皮，并且是患者预后的预测因子。本研究的目的是研究300例缺血性心力衰竭患者体内脂肪含量、营养摄入、炎症和患者结局之间的关系，这些患者平均分布在体重不足、正常体重、超重和肥胖四组。这项前瞻性研究的主要目的是确定体脂量与患者12个月预后（再住院或死亡的复合终点）之间的关系。次要目的是研究体脂量和分布的差异如何改变营养缺乏（四天食物日记）和促炎细胞因子活性（肿瘤坏死因子- α，可溶性tnf - α受体，白细胞介素-6，白细胞介素-1受体拮抗剂和白细胞介素-10）对患者预后的影响。检查体脂含量、营养摄入和促炎细胞因子活性之间的相互作用，将有助于了解超重和肥胖心衰患者预后改善的生物行为机制。这将有助于为超重和肥胖的心衰患者制定新的营养和体重指南。对潜在机制的理解也可以将这些发现应用于体重过轻的患者，从而改善这些患者的预后。

Cardiac cachexia is an independent risk factor for morbidity and mortality in patients with heart failure (HF). In contrast, obesity was recently reported to be associated with decreased risk of morbidity and mortality. The finding that overweight and obese patients with HF have surprisingly better outcomes is in contrast to our current understanding of the relationships between obesity and HF and conflicts with the recommendation that these individuals should lose weight. The biobehavioral mechanisms underlying the differences in outcomes between these groups of patients are not well understood. Nutritional intake is a major contributor to body weight and may also play a crucial role in influencing HF outcomes. Proinflammatory cytokines released as part of the systemic inflammatory response to both obesity and HF affect appetite, food intake, body composition, myocardial function, vascular epithelium, and are predictors of patient outcomes. The purpose of the proposed research is to examine the relationships among body fat content, nutritional intake, inflammation, and patient outcomes in 300 patients with HF of ischemic origin that are equally distributed among four groups: underweight, normal weight, overweight and obese. The primary aim of this prospective study is to determine the relationship between body fat mass and twelve-month patient outcomes (composite end-point of rehospitalization of death). Secondary aims are to examine how differences in body fat mass and distribution alter the effect nutritional deficiencies (four-day food diaries) and proinflammatory cytokine activity (tumor necrosis factor-alpha [TNFalpha], soluble TNF-alpha receptors, interleukin-6, interleukin-1 receptor antagonist, and interleukin-10) on patient outcomes. Examination of the interactions among body fat content, nutritional intake, and proinflammatory cytokine activity will provide an understanding of the biobehavioral mechanisms underlying the improved patient outcomes observed in overweight and obese patients with HF. This will assist with developing new nutrition and body weight guidelines for patients with HF who are overweight and obese. An understanding of the underlying mechanisms may also allow application of these findings to underweight patients resulting in improved outcomes for these patients.