Department of Nephrology, Osaka University Graduate School of Medicine, Suita, Japan.
Department of Inter-Organ Communication Research in Kidney Diseases, Osaka University Graduate School of Medicine, Suita, Japan.
Am J Kidney Dis. 2022 Mar;79(3):374-382. doi: 10.1053/j.ajkd.2021.05.022. Epub 2021 Jul 16.
RATIONALE & OBJECTIVE: High anion gap acidosis frequently develops in patients with advanced chronic kidney disease (CKD) and might be involved in kidney injury. Its impact on kidney outcomes, however, has not been well studied. We sought to examine the association between time-updated anion gap and the risk of kidney failure with replacement therapy (KFRT) among patients with advanced CKD.
Retrospective cohort study.
SETTING & PARTICIPANTS: 1,168 patients with CKD glomerular filtration rate categories 3b-5 (G3b-G5) who had available data on anion gap.
High time-updated anion gap defined as values ≥ 9.2 (top 25th percentile).
KFRT and death.
Marginal structural models were fit to characterize the association between anion gap and study outcomes while accounting for potential time-dependent confounding.
The mean baseline estimated glomerular filtration rate (eGFR) of the study participants was 28 mL/min/1.73 m. Over a median follow-up period of 3.1 years, 317 patients progressed to KFRT (7.5 per 100 patient-years), and 146 died (3.5 per 100 patient-years). In the marginal structural models, a high anion gap was associated with a higher rate of KFRT (HR, 3.04 [95% CI, 1.94-4.75]; P < 0.001). This association was stronger in patients with a baseline eGFR of <30 mL/min/1.73 m (P for interaction = 0.05). High anion gap was also associated with a higher mortality rate (HR, 5.56 [95% CI, 2.95-10.5]; P < 0.001). Sensitivity analyses with different definitions of high anion gap showed similar results.
Observational study design and selection bias due clinical indications for measuring anion gap.
Among patients with advanced CKD, high anion gap was associated with an increased risk of progression to KFRT and death.
在晚期慢性肾脏病（CKD）患者中，常发生高阴离子间隙酸中毒，其可能与肾脏损伤有关。但阴离子间隙与肾脏结局的关系尚未得到很好的研究。本研究旨在探讨晚期 CKD 患者中阴离子间隙的时间变化与肾衰竭需要替代治疗（KFRT）风险之间的关系。
回顾性队列研究。
共纳入 1168 例 CKD 肾小球滤过率（GFR）3b-5 期（G3b-G5）患者，这些患者有阴离子间隙数据。
高时间更新阴离子间隙定义为值≥9.2（第 25 百分位数以上）。
KFRT 和死亡。
采用边缘结构模型来描述阴离子间隙与研究结局之间的关系，同时考虑潜在的时变混杂因素。
研究参与者的平均基线估计肾小球滤过率（eGFR）为 28 mL/min/1.73 m。中位随访时间为 3.1 年期间，317 例患者进展为 KFRT（每 100 患者年 7.5 例），146 例患者死亡（每 100 患者年 3.5 例）。在边缘结构模型中，高阴离子间隙与 KFRT 发生率升高相关（HR，3.04 [95%CI，1.94-4.75]；P < 0.001）。在基线 eGFR <30 mL/min/1.73 m 的患者中，这种相关性更强（交互 P 值=0.05）。高阴离子间隙也与较高的死亡率相关（HR，5.56 [95%CI，2.95-10.5]；P < 0.001）。采用不同高阴离子间隙定义的敏感性分析结果相似。
观察性研究设计和因临床指征测量阴离子间隙而导致的选择偏倚。
在晚期 CKD 患者中，高阴离子间隙与 KFRT 进展和死亡风险增加相关。
