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BackgroundUromodulin (UMOD) is released by renal tubular cells into the serum (sUMOD) and urine. Lower urine UMOD has been linked to mortality and cardiovascular disease but much less is known about sUMOD. We evaluated the association of sUMOD with these outcomes in community-dwelling older adults.MethodsWe measured sUMOD in a random subcohort of 933 participants enrolled in the Cardiovascular Health Study. The associations of sUMOD with all-cause mortality, incident heart failure (HF) and incident cardiovascular disease (CVD; myocardial infarction, stroke and mortality due to coronary disease or stroke) were evaluated using multivariable Cox regression, adjusting for study participants' demographics, estimated glomerular filtration rate (eGFR), albuminuria and CVD risk factors. Generalized additive models with splines were used to address the functional form of sUMOD with outcomes. Due to nonlinear associations of sUMOD with all outcomes, 2.5% of the values on either end of the sUMOD distribution were excluded from the analyses, limiting the range of sUMOD to 34.3-267.1 ng/mL.ResultsThe mean age was 78 ± 5 years, 40% were male, sUMOD level was 127 ± 64 ng/mL, eGFR was 63 mL/min/1.73 m2 and 42% had CKD defined as eGFR

Uromodulin is released into serum (sUMOD) and urine (uUMOD) exclusively by renal tubular cells. Both sUMOD and uUMOD are correlated with estimated glomerular filtration rate (eGFR), and associated with mortality and cardiovascular disease (CVD). However, no study to our knowledge has measured both sUMOD and uUMOD in the same population, thus the relationship of sUMOD with uUMOD with one another, and their respective correlates have not been evaluated simultaneously. We evaluated the correlations of sUMOD, uUMOD with eGFR in a random sub-cohort (n = 933) of the Cardiovascular Health Study and their associations with demographic and laboratory parameters and CVD risk factors using multi-variable linear regression analysis. The mean age of the cohort was 78 years, 40% were male and 15% were Black. The mean sUMOD level was 127 ng/mL, uUMOD was 30 500 ng/mL and eGFR was 63 mL/min/1.73 m2 . Correlation between sUMOD and uUMOD, adjusted for eGFR was moderate (r = 0.27 [95% confidence interval = 0.21-0.33]). The correlation of eGFR with sUMOD (r = 0.44 [0.39-0.49]) was stronger than with uUMOD (r = 0.21 [0.15-0.27]). In multi-variable analysis adjusting sUMOD for uUMOD and vice versa, sUMOD was independently associated with eGFR (β = 1.3 [1.1-1.6]), log2 C-reactive protein (β = -4.2 [-6.8 to -1.6]) and male sex (β = -13.6 [-22.7 to -4.5]). In contrast, male sex was associated with higher uUMOD (β = 3700 [400-7000]), while diabetes (β = -6400 [-10 600 to -2100]) and hypertension (-4300 [-7500 to -1100]) were associated with lower uUMOD levels. We conclude that sUMOD is more strongly associated with eGFR compared with uUMOD. Correlates of sUMOD and uUMOD differ substantially, suggesting that apical and basolateral secretion may be differentially regulated.

Rationale & objectiveUromodulin is released by tubular epithelial cells into the serum and lower levels are associated with more severe interstitial fibrosis and tubular atrophy. Low serum uromodulin (sUMOD) levels are associated with mortality and cardiovascular disease. However, little is known about the association of sUMOD levels with long-term kidney outcomes in older adults, a population with a high prevalence of interstitial fibrosis and tubular atrophy.Study designCase-cohort study and case-control study.Setting & participantsRandom subcohort (n=933) and additional cases of end-stage kidney disease (ESKD) and kidney function decline (≥30% decline in estimated glomerular filtration rate [eGFR]) during follow-up of the Cardiovascular Health Study (CHS).PredictorsUMOD level.OutcomesESKD (n=14) from the random subcohort and all additional ESKD cases from outside the random subcohort (n=39) during follow-up (10 years, case-cohort study); kidney function decline of≥30% eGFR at 9 years of follow-up in individuals with repeated eGFR assessments from the random subcohort (n=56) and additional cases (n=123). 224 participants from the random subcohort served as controls (case-control study).Analytical approachModified multivariable Cox regression for ESKD and multivariable logistic regression for kidney function decline. Both analyses adjusted for demographics, eGFR, urinary albumin-creatinine ratio, and other kidney disease progression risk factors.ResultsMean age of the random subcohort was 78 years, 40% were men, 15% were black. Mean sUMOD level was 127±64ng/mL and eGFR was 63±19mL/min/1.73m2. In multivariable analysis, each 1-SD higher sUMOD level was associated with 63% lower risk for ESKD (HR, 0.37; 95% CI, 0.14-0.95). In demographic-adjusted analyses of kidney function decline, each 1-SD higher sUMOD level was associated with 25% lower odds of kidney function decline (OR, 0.75; 95% CI, 0.60-0.95); after multivariable adjustment, the association was attenuated and no longer significant (OR, 0.88; 95% CI, 0.68-1.14).LimitationsPossibility of survival bias in the kidney function decline analysis.ConclusionsHigher sUMOD levels may identify elderly persons at reduced risk for ESKD.

Data on risk factors predicting rapid progression to end-stage renal disease (ESRD) or short-term kidney function decline (i.e., within 1 year) in chronic kidney disease (CKD) are rare but urgently needed to plan treatment. This study describes the association and predictive value of urinary uromodulin (uUMOD) for rapid progression of CKD.We assessed uUMOD, demographic/treatment parameters, estimated glomerular filtration rate (eGFR), and proteinuria in 230 CKD patients stage I-V. ESRD and 25% decline of eGFR was documented at the end of follow-up period and used as a composite endpoint. Association between logarithmic uUMOD and eGFR/proteinuria was calculated using linear regression analysis, adjusting for age, gender, and body mass index. We performed multivariable Cox proportional hazard regression analysis to evaluate the association of uUMOD with the composite endpoint. Therefore, patients were categorized into quartiles. The predictive value of uUMOD for the above outcomes was assessed using receiver-operating characteristic (ROC) curve analysis.Follow-up was 57.3 ± 18.7 weeks, baseline age was 60 (18;92) years, and eGFR was 38 (6;156) mL/min/1.73 m. Forty-seven (20.4%) patients reached the composite endpoint. uUMOD concentrations were directly associated with eGFR and inversely associated with proteinuria (β = 0.554 and β = -0.429, P

Chronic disease progression models are available for several highly prevalent conditions. For chronic kidney disease (CKD), the scope of existing progression models is limited to the risk of kidney failure and major cardiovascular (CV) events. The aim of this project was to develop a comprehensive CKD progression model (CKD-PM) that simulates the risk of CKD progression and a broad range of complications in patients with CKD. A series of literature reviews informed the selection of risk factors and identified existing risk equations/algorithms for kidney replacement therapy (KRT), CV events, other CKD-related complications, and mortality. Risk equations and transition probabilities were primarily sourced from publications produced by large US and international CKD registries. A patient-level, state-transition model was developed with health states defined by the Kidney Disease Improving Global Outcomes categories. Model validation was performed by comparing predicted outcomes with observed outcomes in the source cohorts used in model development (internal validation) and other cohorts (external validation). The CKD-PM demonstrated satisfactory modeling properties. Accurate prediction of all-cause and CV mortality was achieved without calibration, while prediction of CV events through CKD-specific equations required implementation of a calibration factor to balance time-dependent versus baseline risk. Predicted annual changes in estimated glomerular filtration rate (eGFR) and urine albumin-creatinine ratio were acceptable in comparison to external values. A flexible eGFR threshold for KRT equations enabled accurate prediction of these events. This CKD-PM demonstrated reliable modeling properties. Both internal and external validation revealed robust outcomes. [ABSTRACT FROM AUTHOR]

BackgroundUromodulin is a kidney-derived glycoprotein and putative tubular function index. Lower serum uromodulin was recently associated with increased risk for kidney allograft failure in a preliminary, longitudinal single-center -European study involving 91 kidney transplant recipients (KTRs).MethodsThe Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) trial is a completed, large, multiethnic controlled clinical trial cohort, which studied chronic, stable KTRs. We conducted a case cohort analysis using a randomly selected subset of patients (random subcohort, n = 433), and all individuals who developed kidney allograft failure (cases, n = 226) during follow-up. Serum uromodulin was determined in this total of n = 613 FAVORIT trial participants at randomization. Death-censored kidney allograft failure was the study outcome.ResultsThe 226 kidney allograft failures occurred during a median surveillance of 3.2 years. Unadjusted, weighted Cox proportional hazards modeling revealed that lower serum uromodulin, tertile 1 vs. tertile 3, was associated with a threefold greater risk for kidney allograft failure (hazards ratio [HR], 95% CI 3.20 [2.05-5.01]). This association was attenuated but persisted at twofold greater risk for allograft failure, after adjustment for age, sex, smoking, allograft type and vintage, prevalent diabetes mellitus and cardiovascular disease (CVD), total/high-density lipoprotein cholesterol ratio, systolic blood pressure, estimated glomerular filtration rate, and natural log urinary albumin/creatinine: HR 2.00, 95% CI (1.06-3.77).ConclusionsLower serum uromodulin, a possible indicator of less well-preserved renal tubular function, remained associated with greater risk for kidney allograft failure, after adjustment for major, established clinical kidney allograft failure and CVD risk factors, in a large, multiethnic cohort of long-term, stable KTRs.

Aim: The EMPULSE (EMPagliflozin in patients hospitalised with acUte heart faiLure who have been StabilizEd) trial showed that, compared to placebo, the sodium–glucose cotransporter 2 inhibitor empagliflozin (10 mg/day) improved clinical outcomes of patients hospitalized for acute heart failure (HF). We investigated whether efficacy and safety of empagliflozin were consistent across the spectrum of left ventricular ejection fraction (LVEF). Methods and results: A total of 530 patients hospitalized for acute de novo or decompensated HF were included irrespective of LVEF. For the present analysis, patients were classified as HF with reduced (HFrEF, LVEF ≤40%), mildly reduced (HFmrEF, LVEF 41–49%) or preserved (HFpEF, LVEF ≥50%) ejection fraction at baseline. The primary endpoint was a hierarchical outcome of death, worsening HF events (HFE) and quality of life over 90 days, assessed by the win ratio. Secondary endpoints included individual components of the primary endpoint and safety. Out of 523 patients with baseline data, 354 (67.7%) had HFrEF, 54 (10.3%) had HFmrEF and 115 (22.0%) had HFpEF. The clinical benefit (hierarchical composite of all‐cause death, HFE and Kansas City Cardiomyopathy Questionnaire total symptom score) of empagliflozin at 90 days compared to placebo was consistent across LVEF categories (≤40%: win ratio 1.35 [95% confidence interval 1.04, 1.75]; 41–49%: win ratio 1.25 [0.66, 2.37)] and ≥50%: win ratio 1.40 [0.87, 2.23], pinteraction = 0.96) with a favourable safety profile. Results were consistent across individual components of the hierarchical primary endpoint. Conclusion: The clinical benefit of empagliflozin proved consistent across LVEF categories in the EMPULSE trial. These results support early in‐hospital initiation of empagliflozin regardless of LVEF. [ABSTRACT FROM AUTHOR]

Background/Aims: This study compares the peritoneal elimination of the low-molecular-weight-protein (LMWP) C-terminal agrin fragment (tCAF, size 22 kDa), a promising biomarker for kidney function, in continuous cycling peritoneal dialysis (CCPD) and continuous ambulatory peritoneal dialysis (CAPD). Methods: 103 sets of serum, 24h-urine and dialysate samples were obtained in 15 CCPD (63 sets) and 11 CAPD (40 sets) patients. Total, renal and peritoneal substrate removals/clearances were measured/calculated for tCAF, creatinine, blood-urea-nitrogen (BUN), cystatin C and albumin and correlated with the peritoneal transport type. Results: Serum und urine concentrations of all biomarkers did not differ between both groups, urinary substrate removal was higher in CAPD patients for all biomarkers due to better residual renal function. Peritoneal substrate removal of tCAF and albumin were significantly higher in CAPD (tCAF: 35.3 vs. 19.3 µg/d, p<0.001; albumin: 4.3 vs. 3.7 g/d, p=0.001), whereas cystatin C and creatinine did not differ between CAPD and CCPD (cystatin: 7.7 vs. 6.1 mg/d, p=0.08, creatinine: 423.9 vs. 456.7 mg/d, p=0.241). BUN was better removed by CCPD (4846.6 vs. 3393.4 mg/d, p<0.001). CAPD patients with high-transporter characteristics had a higher peritoneal tCAF removal compared to high-average-transporters (49.8 vs. 28.4 µg/d, p<0.001), no differences could be detected in CCPD patients between these groups. CAPD patients using icodextrin twice/day had higher peritoneal clearance of tCAF compared to once daily (4.4 vs. 2.8 l/wk/1.73 m2 body-surface-area, p<0.001). Conclusions: CAPD was superior to CCPD concerning peritoneal tCAF removal. This finding was pronounced in high-transporters and CAPD patients using icodextrin twice daily. [ABSTRACT FROM AUTHOR]