Examining the robustness of the obesity paradox in maintenance hemodialysis patients: a marginal structural model analysis
Examining the robustness of the obesity paradox in maintenance hemodialysis patients: a marginal structural model analysis
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DOI：
10.1093/ndt/gfv379
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发表时间：
2016-08-01
影响因子：
6.1
通讯作者：
Chen, Joline L. T.
中科院分区：
文献类型：
--
作者：
Doshi, Megha;Streja, Elani;Chen, Joline L. T.
在接受维持性血液透析（MHD）治疗的患者中观察到的体重指数（BMI）与死亡率之间的负相关（也称为肥胖悖论）可能是残留混杂因素的结果。边际结构模型（MSM）分析是一种考虑时变混杂因素的技术，可能更适合研究这种关联。我们假设应用 MSM 后，BMI 与 MHD 患者死亡率之间的负相关性减弱。我们检查了 2001-6 年间接受治疗的 123 624 名成人 MHD 患者的 BMI 与全因死亡率之间的关联。我们使用 Cox 比例风险模型和 MSM 检查基线和随时间变化的 BMI，同时考虑基线和随时间变化的协变量，包括人口统计数据、合并症以及营养不良和炎症标志物。患者包括 45% 的女性和 32% 的非洲裔美国人，平均年龄为 61（SD 15）岁。在所有模型中，BMI 均与死亡率呈线性增量负相关。与参考值（BMI 25 至 < 27.5 kg/m(2)）相比，BMI < 18 kg/m(2) 与死亡风险升高 3.2 倍相关[风险比 (HR) 3.17 (95% CI 3.05-3.29)]，死亡风险随着 BMI 的增加而下降，最大生存优势为风险降低 31% [HR 0.69 (95% CI) 0.64-0.75)] 在 BMI 为 40 至 < 45 kg/m(2) 的情况下观察到。BMI 和死亡率之间的线性负相关在包括 MSM 分析在内的模型中非常稳健，更完整地解释了随时间变化的混杂因素和偏差。
The inverse association between body mass index (BMI) and mortality observed in patients treated with maintenance hemodialysis (MHD), also known as the obesity paradox, may be a result of residual confounding. Marginal structural model (MSM) analysis, a technique that accounts for time-varying confounders, may be more appropriate to investigate this association. We hypothesize that after applying MSM, the inverse association between BMI and mortality in MHD patients is attenuated.We examined the associations between BMI and all-cause mortality among 123 624 adult MHD patients treated during 2001-6. We examined baseline and time-varying BMI using Cox proportional hazards models and MSM while considering baseline and time-varying covariates, including demographics, comorbidities and markers of malnutrition and inflammation.The patients included 45% women and 32% African Americans with a mean age of 61(SD 15) years. In all models, BMI showed a linear incremental inverse association with mortality. Compared with the reference (BMI 25 to < 27.5 kg/m(2)), a BMI of < 18 kg/m(2) was associated with a 3.2-fold higher death risk [hazard ratio (HR) 3.17 (95% CI 3.05-3.29)], and mortality risks declined with increasing BMI with the greatest survival advantage of 31% lower risk [HR 0.69 (95% CI 0.64-0.75)] observed with a BMI of 40 to < 45 kg/m(2).The linear inverse relationship between BMI and mortality is robust across models including MSM analyses that more completely account for time-varying confounders and biases.