The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines proposed the concept of acute kidney disease (AKD) to describe kidney dysfunction that does not meet the diagnostic criteria for either acute kidney injury (AKI) or chronic kidney disease (CKD). However, long-term prognosis, particularly with recovery after AKD, remains unclear. This study aimed to compare long-term outcomes among patients with recovery after AKD (Recovery group), those without recovery (Non-Recovery group), and those without AKD (non-AKD group). Methods: This single-center retrospective cohort study included all adult patients without end-stage kidney disease (ESKD) who underwent at least one blood test at Hamamatsu University Hospital between January 1 and December 31, 2013. The median observation period was 112. 9 months (interquartile range: 57. 7-140. 4months). The first laboratory test performed in 2013 was defined as the index date. AKD was identified based on the KDIGO criteria using serum creatinine (S-Cre) and estimated glomerular filtration rate (eGFR) values within 90 days of the index date. Recovery was evaluated at 6 months after the index date and was defined as meeting either of the following criteria: S-Cre # 1. 25 baseline S-Cre or eGFR 0. 8 baseline eGFR. The primary outcome was all-cause mortality. The secondary outcome was the annual rate of eGFR decline (eGFR slope). Results: Of the 20, 105 eligible patients, 14, 459 met the inclusion criteria and were analyzed. The mean (SD) age was 61. 2 (16. 6) years, and 47. 3% were men. The non-AKD, Recovery, and Non-Recovery groups comprised 13, 830, 291, and 338 patients, respectively. Compared with the non-AKD group, both the Recovery group (hazard ratio HR 2. 08, 95% confidence interval CI 1. 57-2. 74) and the Non-Recovery group (HR 2. 03, 95% CI 1. 50-2. 73) showed significantly higher mortality risk, with no significant difference between the two AKD groups. The between-group differences in 1-year eGFR slope (mL/min/1. 73m 2 /year) versus the non-AKD group were -0. 93 (95% CI, -3. 34 to 1. 47) the Recovery group and -1. 84 (95% CI, -4. 65 to 0. 97) for the Non-Recovery group, with no significant differences. After adjustment for age, sex, renin-angiotensin system inhibitor use, and comorbidities, the results remained consistent (Recovery: -0. 75 95% CI, -3. 16 to 1. 66, Non-Recovery: -0. 92 95% CI -3. 77 to 1. 93). Conclusion: The development of AKD was associated with an increased risk of all-cause mortality, regardless of recovery status. In contrast, the rate of kidney function decline did not differ significantly among the groups. These findings suggest that patients with AKD require careful long-term monitoring even after kidney function recovery. I have no potential conflict of interest to disclose. I used generative AI and AI-assisted technologies in the writing process. During the preparation of this work, the authors used ChatGPT (OpenAI) to improve the readability and language of the English text. After using this tool, the authors carefully reviewed, edited, and verified all content and take full responsibility for the integrity and accuracy of the abstract.
Alahmad et al. (2026) studied this question.