Department of Healthcare Epidemiology, School of Public Health in the Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Department of Nephrology and Dialysis, Kyoritsu Hospital, Hyogo, Japan.
Nephron. 2020;144(3):138-146. doi: 10.1159/000504194. Epub 2020 Feb 4.
Patients undergoing hemodialysis (HD) have higher predialysis plasma osmolality. Several studies have suggested lower osmolality to be associated with worse outcomes in patients not undergoing HD. However, no studies have examined the association between osmolality and mortality among patients undergoing HD.
We aimed to examine the association between predialysis plasma calculated osmolality and all-cause mortality.
This was a prospective cohort study of 1,240 patients undergoing HD participating in the Japanese Dialysis Outcomes and Practice Patterns Study phase 5 (2012-2015). The exposure was predialysis plasma osmolality, calculated as 2 × (serum sodium concentration [mmol/L]) + (serum urea nitrogen [mg/dL])/2.8 + (serum glucose [mg/dL])/18. The primary outcome was all-cause mortality. The secondary outcome was the change in systolic blood pressure (SBP) during HD. We used a marginal structural model with stabilized weights to estimate the association between calculated osmolality and all-cause mortality in the presence of time-varying confounders affected by prior exposure.
Mean baseline plasma calculated osmolality was 306.8 ± 8.6 mOsm/kg. Low predialysis calculated osmolality was associated with higher mortality (adjusted hazard ratio 1.52, 95% confidence interval [CI]: 1.30-1.78 by each 10 mOsm/L lower osmolality). The association was consistent across clinically relevant subgroups. Predialysis osmolality was significantly associated with intradialytic SBP change (mean difference 0.96 [95% CI: 0.05-1.88] mm Hg per each 10 mOsm/L lower osmolality).
Low predialysis calculated osmolality was an independent risk factor of all-cause mortality.
接受血液透析（HD）的患者透析前血浆渗透压较高。多项研究表明，非透析患者的渗透压较低与预后较差相关。然而，尚无研究探讨接受 HD 的患者渗透压与死亡率之间的关系。
本研究旨在探讨透析前血浆计算渗透压与全因死亡率之间的关系。
这是一项针对参加日本透析结局和实践模式研究 5 期（2012-2015 年）的 1240 名接受 HD 的患者的前瞻性队列研究。暴露因素为透析前血浆渗透压，计算方法为 2×（血清钠浓度[mmol/L]）+（血清尿素氮[mg/dL]）/2.8+（血清葡萄糖[mg/dL]）/18。主要结局为全因死亡率。次要结局为 HD 期间收缩压（SBP）的变化。我们使用具有稳定权重的边缘结构模型来估计在存在受先前暴露影响的时变混杂因素的情况下，计算渗透压与全因死亡率之间的关系。
平均基线血浆计算渗透压为 306.8±8.6 mOsm/kg。低透析前计算渗透压与死亡率升高相关（校正后的危险比 1.52，95%置信区间[CI]：每降低 10 mOsm/L 渗透压，死亡率增加 1.30-1.78）。该关联在具有临床意义的亚组中是一致的。透析前渗透压与透析期间 SBP 变化显著相关（每降低 10 mOsm/L 渗透压，SBP 变化平均差值为 0.96[95%CI：0.05-1.88]mmHg）。
低透析前计算渗透压是全因死亡率的独立危险因素。
