Postgraduation Program in Medical Sciences, Medical School, Universidade Federal Fluminense, Rio de Janeiro, Brazil.
Nephrology Division, Pro-rim Foundation, Joinville, Santa Catarina, Brazil.
Hemodial Int. 2023 Oct;27(4):428-435. doi: 10.1111/hdi.13099. Epub 2023 Jun 1.
A phenomenon called the "obesity paradox" has consistently been reported in several cohorts of patients on chronic hemodialysis. In this setting, a higher body mass index (BMI) is paradoxically associated with better survival. This study aimed to evaluate the effect of BMI on mortality in patients undergoing chronic hemodialysis using the Brazilian Dialysis Registry.
This was a retrospective national cohort study with data on incident hemodialysis patients collected between January 2011 to December 2018. Those aged <18 or > 80 years were excluded from the study. The variables studied were the clinical and laboratory data regularly collected at the dialysis units. The variable of primary interest was BMI, represented as the median of the entire dialysis treatment and stratified into four ranges according to the World Health Organization (WHO) classification. The primary outcome was death within 4 years. Cox proportional hazards regression analysis was used to test associations with mortality.
The analyzed sample consisted of 5489 patients from 73 centers in five regions of the country. Of these, 5.9% were underweight, 48.3% were of normal weight, 31.0% were overweight, and 14.7% were obese. The 4-year survival rates in these BMI ranges were 58%, 70%, 75%, and 80%, respectively. The probability of survival for each BMI extract was significantly different from that in the normal-weight range (p < 0.05). In the fully adjusted Cox proportional hazard regression model, BMI > 24.9 kg/m remained an independent protective factor for mortality (HR: 0.76, 95% CI: 0.62-0.95, p = 0.016).
In Brazil, being overweight and obese are protective factors for survival in the chronic hemodialysis population.
在几批接受慢性血液透析的患者队列中，一直有一个被称为“肥胖悖论”的现象。在这种情况下，较高的体重指数（BMI）与更好的生存呈反常相关。本研究旨在使用巴西透析登记处评估 BMI 对接受慢性血液透析患者死亡率的影响。
这是一项回顾性全国队列研究，纳入了 2011 年 1 月至 2018 年 12 月期间新开始血液透析的患者数据。年龄<18 岁或>80 岁的患者被排除在研究之外。研究的变量是在透析单位定期收集的临床和实验室数据。主要关注的变量是 BMI，以整个透析治疗的中位数表示，并根据世界卫生组织（WHO）分类分为四个范围。主要结局是 4 年内死亡。Cox 比例风险回归分析用于检验与死亡率的关联。
分析样本包括来自该国五个地区 73 个中心的 5489 名患者。其中，5.9%为体重不足，48.3%为正常体重，31.0%为超重，14.7%为肥胖。这些 BMI 范围内的 4 年生存率分别为 58%、70%、75%和 80%。每个 BMI 组的生存概率与正常体重范围显著不同（p<0.05）。在完全调整的 Cox 比例风险回归模型中，BMI>24.9 kg/m2 仍然是死亡率的独立保护因素（HR：0.76，95%CI：0.62-0.95，p=0.016）。
在巴西，超重和肥胖是慢性血液透析人群生存的保护因素。
