Tubule dysfunction and injury and future risk of sepsis-associated acute kidney injury.

BACKGROUND: Novel biomarkers can quantify both kidney tubule function, including proximal tubule reabsorptive (urine α-1 microglobulin (uα1m)) and tubule protein synthesis capacities (urine uromodulin (uUMOD)), and tubular injury (urine neutrophil gelatinase-associated lipocalin (uNGAL)). In a blood pressure trial, we reported that lower reabsorptive and synthetic protein capacity at times of health predicted future risk of acute kidney injury (AKI), but most AKI was related to hemodynamic causes in this trial. Associations between tubular function and injury and future AKI related to other causes is unknown. MATERIALS AND METHODS: We performed a case-control study in REGARDS, a population-based cohort study, among participants who provided urine at the baseline visit. We matched each septic AKI case by age, sex, race, and time from baseline to hospital admission 1 : 1 to a participant with sepsis who did not develop AKI (controls). Using conditional logistic regression, we evaluated the associations of uα1m, uUMOD, urine ammonium, and uNGAL with septic AKI. RESULTS: Mean age was 69 ± 8 years, 44% were female, and 39% were Black participants. Median baseline eGFR among cases and controls was 73 (55, 90) and 82 (65, 92) mL/min/1.73m2, and median albuminuria was 19 (8, 87) vs. 9 (5, 22) mg/g, respectively. No independent associations were observed between the tubule function or injury markers and subsequent risk of septic AKI once models were adjusted for baseline albuminuria, estimated glomerular filtration rate, and other risk factors. CONCLUSION: Among community participants, tubule function and injury markers at times of health were not independently associated with future risk of septic AKI.

Prevalence, Mortality, and Access to Care for Chronic Kidney Disease in Medicaid-Enrolled Adults With Sickle Cell Disease in California: Retrospective Cohort Study.

BACKGROUND: Chronic kidney disease (CKD) is a significant complication in patients with sickle cell disease (SCD), leading to increased mortality. OBJECTIVE: This study aims to investigate the burden of CKD in Medicaid-enrolled adults with SCD in California, examine differences in disease burden between male and female individuals, and assess mortality rates and access to specialized care. METHODS: This retrospective cohort study used the California Sickle Cell Data Collection program to identify and monitor individuals with SCD. Medicaid claims, vital records, emergency department, and hospitalization data from 2011 to 2020 were analyzed. CKD prevalence was assessed based on ICD (International Classification of Diseases) codes, and mortality rates were calculated. Access to specialized care was examined through outpatient encounter rates with hematologists and nephrologists. RESULTS: Among the 2345 adults with SCD, 24.4% (n=572) met the case definition for CKD. The SCD-CKD group was older at the beginning of this study (average age 44, SD 14 vs 34, SD 12.6 years) than the group without CKD. CKD prevalence increased with age, revealing significant disparities by sex. While the youngest (18-29 years) and oldest (>65 years) groups showed similar CKD prevalences between sexes (female: 12/111, 10.8% and male: 12/101, 11.9%; female: 74/147, 50.3% and male: 34/66, 51.5%, respectively), male individuals in the aged 30-59 years bracket exhibited significantly higher rates than female individuals (30-39 years: 49/294, 16.7%, P=.01; 40-49 years: 52/182, 28.6%, P=.02; and 50-59 years: 76/157,48.4%, P<.001). During this study, of the 2345 adults, 435 (18.5%) deaths occurred, predominantly within the SCD-CKD cohort (226/435, 39.5%). The median age at death was 53 (IQR 61-44) years for the SCD-CKD group compared to 43 (IQR 33-56) years for the SCD group, with male individuals in the SCD-CKD group showing significantly higher mortality rates (111/242, 45.9%; P=.009) than female individuals (115/330, 34.9%). Access to specialist care was notably limited: approximately half (281/572, 49.1%) of the SCD-CKD cohort had no hematologist visits, and 61.9% (354/572) did not see a nephrologist during this study's period. CONCLUSIONS: This study provides robust estimates of CKD prevalence and mortality among Medicaid-enrolled adults with SCD in California. The findings highlight the need for improved access to specialized care for this population and increased awareness of the high mortality risk and progression associated with CKD.

Mental Health and Autosomal Dominant Polycystic Kidney Disease: A Narrative Review.

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder marked by the development of cysts in the kidneys and other organs, leading to diverse clinical manifestations, including kidney failure. The psychological burden of ADPKD is substantial, with significant contributors including pain, daily life disruptions, depression, anxiety, and the guilt associated with transmitting ADPKD to offspring. This review details the psychological impacts of ADPKD on patients, addressing how they navigate physical and emotional challenges, including pain management, genetic guilt, mood disorders, and disease acceptance. This review also underscores the need for comprehensive research into the psychological aspects of ADPKD, focusing on the prevalence and contributing factors of emotional distress, and identifying effective strategies for managing anxiety and depression. Furthermore, it highlights the importance of understanding the diverse factors that influence patients' quality of life and advocates for holistic interventions to address these psychological challenges.

Urine Ammonium Concentrations and Cardiovascular and Kidney Outcomes in SPRINT Participants with Chronic Kidney Disease.

BACKGROUND: Impaired urine ammonium excretion is common in chronic kidney disease (CKD) and may identify risk of metabolic acidosis earlier than reductions in serum bicarbonate or pH, and thus may have associations with cardiovascular disease (CVD) outcomes. We evaluated the association of urine ammonium with CVD and kidney outcomes among persons with hypertension and non-diabetic CKD enrolled in a trial of blood pressure reduction. METHODS: We measured urine ammonium concentration in spot urine specimens collected at baseline among 2092 participants of the Systolic Blood Pressure Intervention Trial (SPRINT) with an eGFR <60 ml/min/1.73m2. We used multivariable-adjusted Cox models to evaluate associations of urine ammonium concentration with the SPRINT primary CVD composite outcome (myocardial infarction, acute coronary syndrome, stroke, heart failure, or CVD death), all-cause mortality, the SPRINT kidney composite outcome (50% kidney function decline, end stage kidney disease, or transplant), and acute kidney injury (AKI). RESULTS: At baseline, the mean (SD) age was 73 (9) years; 40% were female; and 25% were Black participants. The mean (SD) serum bicarbonate was 25.6 (2.8) mmol/L, median (interquartile range, IQR) urine ammonium concentration was 14.4 (9.5, 23.1) mmol/L, and median (IQR) eGFR was 49 (39,55) ml/min/1.73m2. There were 255 CVD composite events, 143 deaths, 63 kidney composite events, and 146 AKI events during a median follow-up of 3.8 years. In multivariable models, each 2-fold higher urinary ammonium concentration was associated with a 26% (95% CI 1.05, 1.52) higher risk of the CVD composite, whereas there was no association with all-cause mortality, the SPRINT kidney composite outcome, or AKI. CONCLUSION: Among non-diabetic individuals with hypertension and CKD, higher urine ammonium concentration is associated with higher risk of CVD. Further studies are needed to evaluate this association in other cohorts.