Table_1_Transiently Observed Trace Albuminuria on Urine Dipstick Test Is Associated With All-Cause Death, Cardiovascular Death, and Incident Chronic Kidney Disease: A National Health Insurance Service-National Sample Cohort in Korea.DOCX

IntroductionAlbuminuria is a well-known risk factor for end-stage kidney disease, all-cause mortality, and cardiovascular mortality, even when the albumin-to-creatinine ratio is <30 mg/g. However, the association between transiently observed trace albuminuria and these major adverse outcomes has not yet been reported. This study aimed to examine the effect of transient albuminuria on these major adverse outcomes using the National Health Insurance Service data in Korea.
Methods and ResultsThe National Health Insurance Service-National Sample Cohort from Korea, followed from 2002 to 2015, consisted of 1,025,340 individuals, accounting for 2.2% of the total Korean population. We analyzed the effect of transient albuminuria on all-cause death, cardiovascular death, and incident chronic kidney disease (CKD) and compared it with the group without albuminuria. Among 1,025,340 individuals, 121,876 and 2,815 had transient albuminuria and no albuminuria, respectively. Adjusted hazard ratios of the transient albuminuria group for cardiovascular death and incident CKD were 1.76 (1.01–3.08) and 1.28 (1.15–1.43), respectively. There were significant differences in all-cause death, cardiovascular death, and incident CKD between the two groups after propensity score matching (p = 0.0037, p = 0.015, and p < 0.0001, respectively). Propensity score matching with bootstrapping showed that the hazard ratios of the transient albuminuria group for all-cause death and cardiovascular death were 1.39 (1.01–1.92) and 2.18 (1.08–5.98), respectively.
ConclusionsIn this nationwide, large-scale, retrospective cohort study, transient albuminuria was associated with all-cause death, cardiovascular death, and incident CKD, suggesting that transient albuminuria could be a risk marker for adverse outcomes in the future, and that its own subclinical phenotype could play an important role during the course of CKD.

引言
白蛋白尿（albuminuria）是终末期肾病、全因死亡及心血管死亡的公认危险因素，即使白蛋白-肌酐比值（albumin-to-creatinine ratio）<30 mg/g时亦是如此。然而，一过性微量白蛋白尿与上述重大不良结局之间的关联尚未见报道。本研究旨在利用韩国国民健康保险服务（National Health Insurance Service）数据，探讨一过性白蛋白尿对上述主要不良结局的影响。

方法与结果
韩国国民健康保险服务-国家样本队列（National Health Insurance Service-National Sample Cohort）的随访时间为2002年至2015年，共纳入1025340名个体，占韩国总人口的2.2%。本研究分析了一过性白蛋白尿对全因死亡、心血管死亡及新发慢性肾脏病（chronic kidney disease, CKD）的影响，并与无白蛋白尿组进行对比。在1025340名研究对象中，分别有121876名存在一过性白蛋白尿，2815名无白蛋白尿。一过性白蛋白尿组发生心血管死亡和新发CKD的校正后风险比（hazard ratio）分别为1.76（95%置信区间：1.01–3.08）和1.28（95%置信区间：1.15–1.43）。经倾向得分匹配（propensity score matching）后，两组在全因死亡、心血管死亡及新发CKD方面均存在显著差异（分别为p=0.0037、p=0.015、p<0.0001）。结合bootstrap法的倾向得分匹配分析显示，一过性白蛋白尿组发生全因死亡和心血管死亡的风险比分别为1.39（95%置信区间：1.01–1.92）和2.18（95%置信区间：1.08–5.98）。

结论
本项全国性大规模回顾性队列研究表明，一过性白蛋白尿与全因死亡、心血管死亡及新发CKD存在关联，提示一过性白蛋白尿可作为未来不良结局的风险标志物，其本身的亚临床表型可能在慢性肾脏病的病程中发挥重要作用。