Background: Real-world evidence about mineralocorticoid receptor antagonist (MRA) use has been limited in chronic kidney disease, particularly regarding its association with hard renal outcomes. Methods: In this retrospective cohort study, adult chronic kidney disease outpatients referred to the department of nephrology at an academic hospital between January 2005 and December 2018 were analyzed. The main inclusion criteria were estimated glomerular filtration rate ≥10 and <60 mL/min per 1.73 m ² and follow-up ≥90 days. The exposure of interest was MRA use, defined as the administration of spironolactone, eplerenone, or potassium canrenoate. The primary outcome was renal replacement therapy initiation, defined as the initiation of chronic hemodialysis, peritoneal dialysis, or kidney transplantation. A marginal structural model using inverse probability of weighting was applied to account for potential time-varying confounders. Results: Among a total of 3195 patients, the median age and estimated glomerular filtration rate at baseline were 66 years and 38.4 mL/min per 1.73 m ² , respectively. During follow-up (median, 5.9 years), 770 patients received MRAs, 211 died, and 478 started renal replacement therapy. In an inverse probability of weighting-weighted pooled logistic regression model, MRA use was significantly associated with a 28%-lower rate of renal replacement therapy initiation (hazard ratio, 0.72 [95% CI, 0.53–0.98]). The association between MRA use and renal replacement therapy initiation was dose-dependent ( P for trend 5.5 mEq/L) was somewhat higher in MRA users but not significant (hazard ratio, 1.14 [95% CI, 0.88–1.48]). Conclusions: MRA users showed a better renal prognosis across various chronic kidney disease subgroups in a real-world chronic kidney disease population.

Key Points: Restarting renin-angiotensin system inhibitor after discontinuation was associated with a lower risk of kidney outcomes and mortality but not related to hyperkalemia. Our findings support a proactive approach to restarting renin-angiotensin system inhibitor among patients with CKD. Background: While renin-angiotensin system inhibitors (RASi) have been the mainstream treatment for patients with CKD, they are often discontinued because of adverse effects such as hyperkalemia and AKI. It is unknown whether restarting RASi after discontinuation improves clinical outcomes. Methods: Using the Osaka Consortium for Kidney disease Research database, we performed a target trial emulation study including 6065 patients with an eGFR of 10–60 ml/min per 1.73 m ² who were followed up by nephrologists and discontinued RASi between 2005 and 2021. With a clone-censor-weight approach, we compared a treatment strategy for restarting RASi within a year after discontinuation with that for not restarting RASi. Patients were followed up for 5 years at maximum after RASi discontinuation. The primary outcome was a composite kidney outcome (initiation of KRT, a ≥50% decline in eGFR, or kidney failure [eGFR <5 ml/min per 1.73 m ² ]). Secondary outcomes were all-cause death and incidence of hyperkalemia (serum potassium levels ≥5.5 mEq/L). Results: Among those who discontinued RASi (mean [SD] age 66 [15] years, 62% male, mean [SD] eGFR 40 [26] ml/min per 1.73 m ² ), 2262 (37%) restarted RASi within a year. Restarting RASi was associated with a lower hazard of the composite kidney outcome (hazard ratio [HR], 0.85; 95% confidence intervals [CIs], 0.78 to 0.93]) and all-cause death (HR, 0.70; 95% CI, 0.61 to 0.80) compared with not restarting RASi. The incidence of hyperkalemia did not differ significantly between the two strategies (HR, 1.11; 95% CI, 0.96 to 1.27). Conclusions: Restarting RASi after discontinuation was associated with a lower risk of kidney outcomes and mortality but not related to the incidence of hyperkalemia.

Metabolic acidosis is one of the most common complications of chronic kidney disease (CKD). It is associated with the progression of CKD, and many other functional impairments. Until recently, only serum bicarbonate levels have been used to evaluate acid-base changes in patients with reduced kidney function. However, recent emerging evidence suggests that nephrologists should reevaluate the clinical approach for diagnosing metabolic acidosis in patients with CKD based on two perspectives; pH and anion gap. Biochemistry and physiology textbooks clearly indicate that blood pH is the most important acid-base parameter for cellular function. Therefore, it is important to determine if the prognostic impact of hypobicarbonatemia varies according to pH level. A recent cohort study of CKD patients showed that venous pH modified the association between a low bicarbonate level and the progression of CKD. Furthermore, acidosis with a high anion gap has recently been recognized as an important prognostic factor, because veverimer, a nonabsorbable hydrochloride-binding polymer, has been shown to improve kidney function and decrease the anion gap. Acidosis with high anion gap frequently develops in later stages of CKD. Therefore, the anion gap is a time-varying factor and renal function (estimated glomerular filtration rate) is a time-dependent confounder for the anion gap and renal outcomes. Recent analyses using marginal structural models showed that acidosis with a high anion gap was associated with a high risk of CKD. Based on these observations, reconsideration of the clinical approach to diagnosing and treating metabolic acidosis in CKD may be warranted.

Chronic kidney disease (CKD) is a global health crisis affecting over 10% of the population, with mortality rates increasing significantly. Current management strategies, including expensive medications and renal replacement therapies, highlight the need for cost-effective, conservative approaches. This review examines the evidence for plant-dominant low-protein diets (PLADO) in managing non-dialysis-dependent CKD. Existing guidelines for protein restriction in CKD vary considerably, with inconsistencies and a lack of personalization noted in the KDOQI and KDIGO recommendations. While traditional low-protein diet trials show limited success due to poor adherence and marginal benefits, PLADO offers a potentially more sustainable alternative. PLADO’s advantages include improved nutrient density, reduced dietary acid load, anti-inflammatory effects, and beneficial modulation of the gut microbiome, potentially reducing uremic toxins and improving cardiovascular health. However, challenges remain, including adherence issues, potential nutrient deficiencies, and potassium management. Although observational studies show promise, further large-scale randomized controlled trials are necessary to validate PLADO’s efficacy and establish optimal dietary composition. A personalized, multidisciplinary approach is essential for successful implementation and monitoring to maximize PLADO’s benefits in improving outcomes for individuals with NDD-CKD.

Background: Interstitial eosinophilic aggregates are observed in various kidney diseases, but their clinical implications remain unknown. We assessed the association between interstitial eosinophilic aggregates and kidney outcomes and further analyzed the association between blood eosinophil count, as a surrogate for interstitial eosinophilic aggregates, and the risk of kidney failure in patients with advanced CKD. Methods: We analyzed datasets from two retrospective cohort studies: (1) the kidney biopsy cohort including 563 patients who underwent native kidney biopsy at Osaka University Hospital between 2009 and 2021 and (2) the retrospective CKD cohort including 2877 patients with an eGFR of 10–60 ml/min per 1.73 m² referred to the nephrology outpatient center at Osaka University Hospital between 2005 and 2018. Interstitial eosinophilic aggregates were defined as ≥5 interstitial eosinophils in the high-power field on hematoxylin and eosin staining. This study outcome was initiation of KRT or ≥40% decline in eGFR. Results: In the kidney biopsy cohort, interstitial eosinophilic aggregates were found in 17% of patients, most frequently in those with diabetic nephropathy (50%). Interstitial eosinophilic aggregates were associated with a higher rate of the composite kidney outcome after adjustment for clinical and histological variables (hazard ratio, 3.61; 95% confidence interval, 2.47 to 5.29; P < 0.001). LASSO revealed that blood eosinophil count was the strongest predictor of interstitial eosinophilic aggregates. In the retrospective CKD cohort, higher baseline and time-updated blood eosinophil counts were significantly associated with a higher rate of KRT initiation in Cox proportional hazards models and marginal structural models. Conclusions: Interstitial eosinophilic aggregates were associated with a higher risk of a composite of KRT initiation or ≥40% decline in eGFR. Podcast: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_11_10_CJN0000000000000277.mp3