Davenport Daniel L, Xenos Eleftherios S, Hosokawa Patrick, Radford Jacob, Henderson William G, Endean Eric D
Department of Surgery, University of Kentucky, Lexington, KY 40536-0298, USA.
J Vasc Surg. 2009 Jan;49(1):140-7, 147.e1; discussion 147. doi: 10.1016/j.jvs.2008.08.052. Epub 2008 Nov 22.
Mild obesity may have a protective effect against some diseases, termed an "obesity paradox." This study examined the effect of body mass index (Kg/m(2) BMI) on surgical 30-day morbidity and mortality in patients undergoing vascular surgical procedures.
As part of the National Surgical Quality Improvement Program (NSQIP), demographic and clinical risk variables, mortality, and 22 defined complications (morbidity) were obtained over three years from vascular services at 14 medical centers. At each medical center, patients from the operative schedule were prospectively and systematically enrolled according to NSQIP protocols. Outcomes and risk variables were compared across NIH-defined obesity classes (underweight [BMI<or=18.5], normal [18.5<BMI<25], overweight [25<BMI<or=30], obese I [30<BMI<or=35], obese II [35<BMI<or=40], and obese III [BMI>40]) using analysis of variance and means comparisons. Logistic regression was used to control for other risk factors.
Vascular procedures in 7,543 patients included lower extremity revascularization (24.6%), aneurysm repair (17.4%), cerebrovascular procedures (17.3%), amputations (9.4%), and "other" procedures (31.3%). In the entire cohort, there were 1,659 (22.0%) patients with complications and 295 (3.9%) deaths. Risk factors of hypertension and diabetes increased with BMI (analysis of variance [ANOVA] P < .05) as expected; smoking, disseminated cancer, and stroke decreased (ANOVA P < .01). Twenty other risk factors, as well as mortality and morbidity, had "U" or "J"-shaped distributions with the highest incidence in underweight and/or obese class III extremes but reduced minimums in overweight or obese I classes (ANOVA P < .05). After controlling for age, gender, and operation type, mortality risk remained lowest in obese class I patients (Odds ratio [OR] 0.63, P = .023) while morbidity risk was highest in obese class III patients (OR 1.70, P = .0003), due to wound infection, thromboembolism, and renal complications.
Underweight patients have poorer outcomes and class III obesity is associated with increased morbidity. Mildly obese patients have reduced co-morbid illness, surprisingly even less than normal-class patients, with correspondingly reduced mortality. Mild obesity is not a risk factor for 30-day outcomes after vascular surgery and confers an advantage.
轻度肥胖可能对某些疾病具有保护作用，这被称为“肥胖悖论”。本研究探讨了体重指数（千克/平方米，BMI）对接受血管外科手术患者术后30天发病率和死亡率的影响。
作为国家外科质量改进计划（NSQIP）的一部分，在三年时间里，从14个医疗中心的血管外科获取了人口统计学和临床风险变量、死亡率以及22种明确的并发症（发病率）数据。在每个医疗中心，根据NSQIP方案，对手术安排中的患者进行前瞻性和系统性登记。使用方差分析和均值比较，对美国国立卫生研究院定义的肥胖类别（体重过轻[BMI≤18.5]、正常[18.5＜BMI＜25]、超重[25＜BMI≤30]、肥胖I级[30＜BMI≤35]、肥胖II级[35＜BMI≤40]和肥胖III级[BMI＞40]）的结局和风险变量进行比较。采用逻辑回归控制其他风险因素。
7543例患者接受的血管手术包括下肢血管重建术（24.6%）、动脉瘤修复术（17.4%）、脑血管手术（17.3%）、截肢术（9.4%）和“其他”手术（31.3%）。在整个队列中，有1659例（22.0%）患者出现并发症，295例（3.9%）死亡。正如预期的那样，高血压和糖尿病的风险因素随BMI升高（方差分析[ANOVA]P＜0.05）；吸烟、播散性癌症和中风则降低（ANOVA P＜0.01）。其他20个风险因素以及死亡率和发病率呈“U”形或“J”形分布，在体重过轻和/或肥胖III级极端情况下发病率最高，但在超重或肥胖I级时最低（ANOVA P＜0.05）。在控制年龄、性别和手术类型后，肥胖I级患者的死亡风险仍然最低（优势比[OR]0.63，P = 0.023），而肥胖III级患者的发病风险最高（OR 1.70，P = 0.0003），原因是伤口感染、血栓栓塞和肾脏并发症。
体重过轻的患者结局较差，III级肥胖与发病率增加相关。轻度肥胖患者的合并症较少，令人惊讶的是甚至比正常体重患者还少，相应地死亡率也降低。轻度肥胖不是血管手术后30天结局的风险因素，反而具有优势。
