Echocardiographic parameters and cardiovascular disease in Japanese- and US-based CKD cohorts.

Japanese and US populations have similar chronic kidney disease prevalence but differing clinical outcomes. A secondary analysis compared cardiovascular outcomes in a Japanese- and a US-based chronic kidney disease cohort and found that the US cohort had markedly worse cardiovascular outcomes. Mediation analysis demonstrated that differences in left ventricular structure and function could explain most of the cardiovascular outcome difference. We examine and contextualize this finding and describe implications for precision nephrology and for population health.

Kidney health and function with left ventricular assist devices.

PURPOSE OF REVIEW: Mechanical circulatory support (MCS) is a group of evolving therapies used for indications ranging from temporary support during a cardiac procedure to permanent treatment of advanced heart failure. MCS is primarily used to support left ventricle function, in which case the devices are termed left ventricular assist devices (LVADs). Kidney dysfunction is common in patients requiring these devices, yet the impact of MCS itself on kidney health in many settings remains uncertain. RECENT FINDINGS: Kidney dysfunction can manifest in many different forms in patients requiring MCS. It can be because of preexisting systemic disorders, acute illness, procedural complications, device complications, and long-term LVAD support. After durable LVAD implantation, most persons have improvement in kidney function; however, individuals can have markedly different kidney outcomes, and novel phenotypes of kidney outcomes have been identified. SUMMARY: MCS is a rapidly evolving field. Kidney health and function before, during, and after MCS is relevant to outcomes from an epidemiologic perspective, yet the pathophysiology underlying this is uncertain. Improved understanding of the relationship between MCS use and kidney health is important to improving patient outcomes.

Heart Failure-Type Symptom Score Trajectories in CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study.

RATIONALE & OBJECTIVE: Quality of life in chronic kidney disease (CKD) is impaired by a large burden of symptoms including some that overlap with the symptoms of heart failure (HF). We studied a group of individuals with CKD to understand the patterns and trajectories of HF-type symptoms in this setting. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 3,044 participants in the Chronic Renal Insufficiency Cohort (CRIC) without prior diagnosis of HF. PREDICTORS: Sociodemographics, medical history, medications, vital signs, laboratory values, echocardiographic and electrocardiographic parameters. OUTCOME: Trajectory over 5.5 years of a HF-type symptom score (modified Kansas City Cardiomyopathy Questionnaire [KCCQ] Overall Summary Score with a range of 0-100 where<75 reflects clinically significant symptoms). ANALYTICAL APPROACH: Latent class mixed models were used to model trajectories. Multinomial logistic regression was used to model relationships of predictors with trajectory group membership. RESULTS: Five trajectories of KCCQ score were identified in the cohort of 3,044 adults, 45% of whom were female, and whose median age was 61 years. Group 1 (41.7%) had a stable high score (minimal symptoms, average score of 96); groups 2 (35.6%) and 3 (15.6%) had stable but lower scores (mild symptoms [average of 81] and clinically significant symptoms [average of 52], respectively). Group 4 (4.9%) had a substantial worsening in symptoms over time (mean 31-point decline), and group 5 (2.2%) had a substantial improvement (mean 33-point increase) in KCCQ score. A majority of group 1 was male, without diabetes or obesity, and this group had higher baseline kidney function. A majority of groups 2 and 3 had diabetes and obesity. A majority of group 4 was male and had substantial proteinuria. Group 5 had the highest proportion of baseline cardiovascular disease (CVD). LIMITATIONS: No validation cohort available, CKD management changes in recent years may alter trajectories, and latent class models depend on the missing at random assumption. CONCLUSIONS: Distinct HF-type symptom burden trajectories were identified in the setting of CKD, corresponding to different baseline characteristics. These results highlight the diversity of HF-type symptom experiences in individuals with CKD.

Heart failure-type symptom scores in chronic kidney disease: The importance of body mass index.

OBJECTIVES: This analysis sought to determine factors (including adiposity-related factors) most associated with HF-type symptoms (fatigue, shortness of breath, and edema) in adults with chronic kidney disease (CKD). BACKGROUND: Symptom burden impairs quality of life in CKD, especially symptoms that overlap with HF. These symptoms are common regardless of clinical HF diagnosis, and may be affected by subtle cardiac dysfunction, kidney dysfunction, and other factors. We used machine learning to investigate cross-sectional relationships of clinical variables with symptom scores in a CKD cohort. METHODS: Participants in the Chronic Renal Insufficiency Cohort (CRIC) with a baseline modified Kansas City Cardiomyopathy Questionnaire (KCCQ) score were included, regardless of prior HF diagnosis. The primary outcome was Overall Summary Score as a continuous measure. Predictors were 99 clinical variables representing demographic, cardiac, kidney and other health dimensions. A correlation filter was applied. Random forest regression models were fitted. Variable importance scores and adjusted predicted outcomes are presented. RESULTS: The cohort included 3426 individuals, 10.3% with prior HF diagnosis. BMI was the most important factor, with BMI 24.3 kg/m2 associated with the least symptoms. Symptoms worsened with higher or lower BMIs, with a potentially clinically relevant 5 point score decline at 35.7 kg/m2 and a 1-point decline at the threshold for low BMI, 18.5 kg/m2. The most important cardiac and kidney factors were heart rate and eGFR, the 4th and 5th most important variables, respectively. Results were similar for secondary analyses. CONCLUSIONS: In a CKD cohort, BMI was the most important feature for explaining HF-type symptoms regardless of clinical HF diagnosis, identifying an important focus for symptom directed investigations.

Mortality, Kidney Failure, and Hospitalization Among Medicare Beneficiaries With CKD and Pulmonary Hypertension.

RATIONALE & OBJECTIVE: Pulmonary hypertension (PH) is highly prevalent among patients with chronic kidney disease (CKD) not requiring kidney replacement therapy. We studied the associations of PH with mortality, kidney failure, as well as cardiovascular (CV) and non-CV hospitalization among Medicare beneficiaries with a CKD diagnosis. STUDY DESIGN: Retrospective, observational study using a matched cohort design. SETTING & PARTICIPANTS: Patients with PH (based on 2 claims within 2 years) and patients without PH matched on CKD stage from the Medicare 5% CKD sample (1996-2016). PREDICTOR: Presence of pulmonary hypertension. OUTCOME: Mortality, kidney failure, and all-cause, CV, and non-CV hospitalization. ANALYTICAL APPROACH: Cox proportional hazards models to assess the association between PH and mortality, adjusting for age, sex, race, and comorbidities. Death was considered as a competing event in Fine-Gray models to assess the association between PH and kidney failure. Negative binomial model was used to evaluate the relationship between PH and all-cause, CV, and non-CV hospitalizations. RESULTS: 30,052 patients with PH and CKD and 150,260 CKD stage-matched patients without diagnosed PH were studied. The median age of the study population was 80.7 years, 57.8% were women, and 10.3% were African Americans. The presence of PH was associated with an increased risk of mortality after 1 (HR, 2.87 [95% CI, 2.79-2.95]), 2-3 (HR, 1.56 [95% CI, 1.51-1.61]), and 4-5 (HR, 1.47 [95% CI, 1.40-1.53]) years of follow-up, and a higher risk of all-cause, CV, and non-CV hospitalization during the same period. PH was also associated with kidney failure in after 1 and 2-3 years but not after 4-5 years of follow-up evaluation. Patients with PH also experienced higher rates of acute kidney injury (AKI), and AKI requiring dialysis support within 30 and 90 days of AKI. LIMITATIONS: Reliance on billing codes and lack of echocardiogram or right heart catheterization data CONCLUSIONS: Among older Medicare beneficiaries with a CKD diagnosis not requiring kidney replacement therapy, the presence of PH was associated with an increased risk of mortality, kidney failure, and hospitalization. Understanding of the mechanism of these associations, especially the increased risk of kidney failure, requires further study.

Nonesterified Fatty Acids and Kidney Function Decline in Older Adults: Findings From the Cardiovascular Health Study.

RATIONALE & OBJECTIVE: Circulating nonesterified fatty acids (NEFAs) make up a small portion of circulating lipids but are a metabolically important energy source. Excessive circulating NEFAs may contribute to lipotoxicity in many tissues, including the kidneys. We investigated the relationship between total circulating NEFA concentration and kidney outcomes in older, community-dwelling adults. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 4,698 participants≥65 years of age in the Cardiovascular Health Study who underwent total fasting serum NEFA concentration measurements in 1992-1993. EXPOSURE: Fasting serum NEFA concentration at one time point. OUTCOME: Three primary outcomes: estimated glomerular filtration rate (eGFR) decline of≥30%, the composite of eGFR decline≥30% or kidney failure with replacement therapy, and change in eGFR. These outcomes were assessed over 4- and 13-year periods. ANALYTICAL APPROACH: Logistic regression for the dichotomous outcomes and mixed effects models for the continuous outcome, with sequential adjustment for baseline covariates. Inverse probability of attrition weighting was implemented to account for informative attrition during the follow-up periods. RESULTS: Serum NEFA concentrations were not independently associated with kidney outcomes. In unadjusted and partially adjusted analyses, the highest quartile of serum NEFA concentration (compared with lowest) was associated with a higher risk of≥30% eGFR decline at 4 years and faster rate of decline of eGFR. No associations were evident after adjustment for comorbidities, lipid levels, insulin sensitivity, medications, and vital signs: the odds ratio for the eGFR decline outcome was 1.33 (95% CI, 0.83-2.13), and the difference in eGFR slope in the highest versus lowest quartile of serum NEFA concentration was-0.15 (95% CI, -0.36 to 0.06) mL/min/1.73m2 per year. LIMITATIONS: Single NEFA measurements, no measurements of post-glucose load NEFA concentrations or individual NEFA species, no measurement of baseline urine albumin. CONCLUSIONS: A single fasting serum NEFA concentration was not independently associated with long-term adverse kidney outcomes in a cohort of older community-living adults.

Renin-angiotensin system blocker discontinuation and adverse outcomes in chronic kidney disease.

BACKGROUND: Treatment with renin-angiotensin system inhibitors (RASIs), angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) is the standard of care for those with chronic kidney disease (CKD) and albuminuria. However, ACEI/ARB treatment is often discontinued for various reasons. We investigated the association of ACEI/ARB discontinuation with outcomes among US veterans with non-dialysis-dependent CKD. METHODS: We performed a retrospective cohort study of patients in the Veterans Affairs healthcare system with non-dialysis-dependent CKD who subsequently were started on ACEI/ARB therapy (new user design). Discontinuation events were defined as a gap in ACEI/ARB therapy of ≥14 days and were classified further based on duration (14-30, 31-60, 61-90, 91-180 and >180 days). This was treated as a time-varying risk factor in adjusted Cox proportional hazards models for the outcomes of death and incident end-stage kidney disease (ESKD), which also adjusted for relevant confounders. RESULTS: We identified 141 252 people with CKD and incident ACEI/ARB use who met the inclusion criteria; these were followed for a mean 4.87 years. There were 135 356 discontinuation events, 68 699 deaths and 6152 incident ESKD events. Discontinuation of ACEI/ARB was associated with a higher risk of death [hazard ratio (HR) 2.3, 2.0, 1.99, 1.92 and 1.74 for those discontinued for 14-30, 31-60, 61-90, 91-180 and >180 days, respectively]. Similar associations were noted between ACEI and ARB discontinuation and ESKD (HR 1.64, 1.47, 1.54, 1.65 and 1.59 for those discontinued for 14-30, 31-60, 61-90, 91-180 and >180 days, respectively). CONCLUSIONS: In a cohort of predominantly male veterans with CKD Stages 3 and 4, ACEI/ARB discontinuation was independently associated with an increased risk of subsequent death and ESKD. This may be due to the severity of illness factors that drive the decision to discontinue therapy. Further investigations to determine the causes of discontinuations and to provide an evidence base for discontinuation decisions are needed.

Prevalence, correlates and outcomes of absolute and functional iron deficiency anemia in nondialysis-dependent chronic kidney disease.

BACKGROUND: Anemia is associated with adverse outcomes in those with chronic kidney disease (CKD). We examined the association of absolute and functional iron deficiency anemia (IDA) with adverse outcomes (cardiovascular hospitalization, dialysis and mortality) in those with nondialysis-dependent CKD. METHODS: Nondialysis-dependent CKD patients followed in the US Veterans Administration with hemoglobin level measured within 90 days of the date of the second estimated glomerular filtration rate <60 mL/min/1.73 m2 were included. Logistic regression, multivariate Cox proportional hazards and Poisson regression models adjusted for demographics and comorbidities were used to assess the prevalence and correlates of absolute [transferrin saturation (TSAT) ≤20%, ferritin <100 ng/mL] and functional (TSA T≤20%, ferritin >100-500 ng/mL) IDA and the associations of absolute and functional IDA with mortality, dialysis and cardiovascular hospitalization. RESULTS: Of 933 463 patients with CKD, 20.6% had anemia. Among those with anemia, 23.6% of patients had both TSAT and ferritin level measured, of whom 30% had absolute IDA and 19% had functional IDA. Absolute IDA in CKD was not associated with an increased risk of mortality or dialysis but was associated with a higher risk of 1-year {risk ratio [RR] 1.20 [95% confidence interval (CI) 1.12-1.28]} and 2-year cardiovascular hospitalization [RR 1.11 (95% CI 1.05-1.17)]. CKD patients with functional IDA had a higher risk of mortality [hazard ratio (HR) 1.11 (95% CI 1.07-1.14)] along with a higher risk of 1-year [RR 1.21 (95% CI 1.1-1.30)] and 2-year cardiovascular hospitalization [RR 1.13 (95% CI 1.07-1.21)]. Ferritin >500 ng/mL (treated as a separate category) was only associated with an increased risk of mortality [HR 1.38 (95% CI 1.26-1.51)]. CONCLUSIONS: In a large population of CKD patients with anemia, absolute and functional IDA were associated with various clinical covariates. Functional IDA was associated with an increased risk of mortality and cardiovascular hospitalization, but absolute IDA was associated only with a higher risk of hospitalization.

Iron deficiency and iron therapy in heart failure and chronic kidney disease.

PURPOSE OF REVIEW: Iron deficiency is common and associated with adverse outcomes in heart failure, regardless of anemia. Iron deficiency, absolute and functional, with and without anemia, is associated with adverse outcomes in chronic kidney disease (CKD). Heart failure and CKD frequently occur together. Intravenous iron therapy has been shown to reduce heart failure symptoms and improve physical function in heart failure with reduced ejection fraction with iron deficiency. In CKD, intravenous or oral iron therapy are often used for management of anemia, along with erythropoiesis stimulating agents, yet the risks and benefits of intravenous iron use is controversial. In this review, we survey available evidence and ongoing studies of iron deficiency and iron supplementation in heart failure, and integrate with recent evidence on effectiveness and safety of intravenous iron therapy in CKD. RECENT FINDINGS: Intravenous iron therapy improves heart failure symptoms and physical function in heart failure with reduced ejection fraction and iron deficiency, regardless of anemia, and may reduce heart failure hospitalizations and cardiovascular mortality. Sustained intravenous iron therapy regardless of hemoglobin level in selected patients with end-stage kidney disease receiving hemodialysis improves outcomes, and does not appear to cause infectious complications. SUMMARY: Iron therapy has important effects in heart failure and CKD, and appears safe in the short term. Ongoing trials will provide additional important information.

Diagnosis and Management of Pulmonary Hypertension in Patients With CKD.

Pulmonary hypertension (PH) is a highly prevalent and important condition in adults with chronic kidney disease (CKD). In this review, we summarize the definition of PH, discuss its pathophysiology and classifications, and describe diagnostic and management strategies in patients with CKD, including those with kidney failure treated by kidney replacement therapy. In the general population, PH is classified into 5 groups based on clinical presentation, pathology, hemodynamics, and management strategies. In this classification system, PH in CKD is placed in a diverse group with unclear or multifactorial mechanisms, although underlying cardiovascular disease may account for most cases. CKD may itself directly incite pulmonary circulatory dysfunction and remodeling through uremic toxins, inflammation, endothelial dysfunction, and altered vasoregulation. Despite several studies describing the higher prevalence of PH in CKD and kidney failure, along with an association with poor outcomes, high-quality evidence is not available for its diagnostic and management strategies in those with CKD. In CKD not requiring kidney replacement therapy, volume management along with treatment of underlying risk factors for PH are critical. In those receiving hemodialysis, options are limited and transition to peritoneal dialysis may be considered if recurrent hypotension precludes optimal volume control.

Readmissions after Acute Kidney Injury during Left Ventricular Assist Device Implantation Hospitalization.

BACKGROUND: Acute kidney injury (AKI) frequently complicates hospitalizations for left ventricular assist device (LVAD) implantation. Little is known about the relationship of AKI with subsequent readmissions, and we investigated the relationship of AKI during LVAD implantation hospitalization with all-cause and cause-specific 30-day readmissions. METHODS: We used a United States (US) nationwide all-payer administrative database, identifying patients who underwent implantable LVAD placement 2010-2015. Patients were classified into 3 mutually exclusive groups based on presence and severity of AKI during the LVAD placement hospitalization: no AKI, AKI, and AKI requiring dialysis (AKI-D). Outcomes were all-cause and cause-specific 30-day readmissions. RESULTS: Within 30 days after discharge 25.4% of patients were readmitted. Of those without AKI, 23.9% were readmitted, compared to 25.5% of those with AKI and 42.2% of those with AKI-D. Compared to no AKI (adjusted for demographics, index hospitalization and chronic comorbidity factors, and year), odds of 30-day readmission were 2.18 (95% CI 1.37-3.49) times higher for those with AKI-D, whereas those with AKI not requiring dialysis had similar 30-day readmission risk (OR 1.03 [95% CI 0.89-1.20]). Those with AKI-D had higher risk of 30-day readmission for infection (OR 2.02 [95% CI 1.13-3.61]), gastrointestinal (GI) bleed (2.32 [95% CI 1.24-4.34]), and kidney disease (13.9 [95% CI 4.0-48]). There was no increased risk for stroke readmission with AKI or AKI-D. CONCLUSION: AKI-D was associated with highest -30-day readmission risk, possibly related to negatively synergistic effects of LVAD, kidney dysfunction, and dialysis related factors on infection and GI bleeding risks. AKI alone was not associated with increased readmission risk.

Association between intensity of statin therapy and mortality in persons with chronic kidney disease.

BACKGROUND: The 2013 American College of Cardiology/American Heart Association lipid guideline recommends statin dosing based on intensity, rather than targeting specific low-density lipoprotein cholesterol (LDL-C) concentrations, among general populations. The 2013 Kidney Disease: Improving Global Outcomes (KDIGO) lipid guideline recommends statins for most adults with chronic kidney disease (CKD), but dose-dependent statin effects in CKD are unclear. METHODS: We performed a retrospective cohort study of US veterans with CKD Stages G3a, G3b or G4, and new, persistent statin use, from 2005 to 2015. We tested the association of intensity of statin therapy [categorized as low (expected LDL-C reduction <30%), medium (30 to <50%) or high (≥50%)] during the initial 1-year exposure period, with all-cause mortality over the subsequent 4 years. We used Cox proportional hazard models to evaluate the association between statin intensity and all-cause mortality, adjusting for demographics, comorbidities and laboratory measurements. RESULTS: Our cohort included 65 292 persons, of whom 40 124 (61.5%) had CKD G3a, 20 183 (30.9%) G3b and 4985 (7.6%) G4. Overall, 4878 (7.5%) used high-intensity, 39 070 (59.8%) used moderate-intensity and 21 344 (32.7%) used low-intensity statins. High-intensity statins were used more in recent years, and among persons diagnosed with atherosclerotic cardiovascular disease. There was no association between statin intensity and mortality in unadjusted or multivariable-adjusted analyses. CONCLUSIONS: There were no significant associations between statin intensity over 1 year of exposure and subsequent mortality among US veterans with CKD. This supports the current KDIGO guideline recommendations to use statins and dosages that have been studied specifically in CKD populations, rather than intensity-based dosing.

The cost-effectiveness of lipid lowering for primary cardiovascular prevention in chronic kidney disease: moving beyond statins.

Because of high risk of cardiovascular disease, patients with chronic kidney disease may benefit from cholesterol-lowering therapy beyond statins. A cost-effectiveness analysis of adding ezetimibe to high-dose statins for primary cardiovascular disease prevention in patients with non-dialysis-dependent chronic kidney disease found treatment with ezetimibe to be cost-effective for many patients with chronic kidney disease. We describe the importance of this topic and explain key assumptions necessary for the investigators to arrive at their conclusions.

Acute Kidney Injury With Ventricular Assist Device Placement: National Estimates of Trends and Outcomes.

RATIONALE & OBJECTIVE: Ventricular assist devices (VADs) are used for end-stage heart failure not amenable to medical therapy. Acute kidney injury (AKI) in this setting is common due to heart failure decompensation, surgical stress, and other factors. Little is known about national trends in AKI diagnosis and AKI requiring dialysis (AKI-D) and associated outcomes with VAD implantation. We investigated national estimates and trends for diagnosed AKI, AKI-D, and associated patient and resource utilization outcomes in hospitalizations in which implantable VADs were placed. STUDY DESIGN: Cohort study of 20% stratified sample of US hospitalizations. SETTING & PARTICIPANTS: Patients who underwent implantable VAD placement in 2006 to 2015. EXPOSURE: No AKI diagnosis, AKI without dialysis, AKI-D. OUTCOMES: In-hospital mortality, length of stay, estimated hospitalization costs. ANALYTICAL APPROACH: Multivariate logistic and linear regression using survey design methods to account for stratification, clustering, and weighting. RESULTS: An estimated 24,140 implantable VADs were placed, increasing from 853 in 2006 to 3,945 in 2015. AKI was diagnosed in 56.1% of hospitalizations and AKI-D occurred in 6.5%. AKI diagnosis increased from 44.0% in 2006 to 2007 to 61.7% in 2014 to 2015; AKI-D declined from 9.3% in 2006 to 2007 to 5.2% in 2014 to 2015. Mortality declined in all AKI categories but this varied by category: those with AKI-D had the smallest decline. Adjusted hospitalization costs were 19.1% higher in those with diagnosed AKI and 39.6% higher in those with AKI-D, compared to no AKI. LIMITATIONS: Administrative data; timing of AKI with respect to VAD implantation cannot be determined; limited pre-existing chronic kidney disease ascertainment; discharge weights not derived for subpopulation of interest. CONCLUSIONS: A decreasing proportion of patients undergoing VAD implantation experience AKI-D, but mortality among these patients remains high. AKI diagnosis with VAD implantation is increasing, possibly reflecting changes in AKI surveillance, awareness, and coding.

Blood pressure parameters and morbid and mortal outcomes in nondialysis-dependent chronic kidney disease.

PURPOSE OF REVIEW: Observational and interventional studies provide conflicting evidence regarding optimal blood pressure (BP) control in persons with chronic kidney disease (CKD). Recent publications provide additional information to inform therapeutic decision-making. RECENT FINDINGS: Targeting SBP to less than 120 mmHg, versus less than 140 mmHg, decreased cardiovascular events and all-cause mortality in persons with nondiabetic CKD. A meta-analysis of trials testing blood pressure management among nondialysis-dependent CKD patients (15 924 total patients) found more intensive therapies generally reduced mortality in all subgroups. Observational studies demonstrate that low SBP is associated with higher mortality in CKD. A recent report suggests that this is because of death from cardiovascular and noncardiovascular and nonmalignant causes, whereas higher BP is associated with death from cardiovascular causes. The shape of association between BP and cardiovascular and noncardiovascular events also appears to vary depending on baseline risk factors. Furthermore, BP measurement methodology may differ importantly between observational and interventional studies. SUMMARY: We review and summarize observational and interventional literature relating BP parameters to key clinical outcomes in persons with CKD. Apart from the inherent differences between these study designs, the disparate findings from trials and observational studies may be because of differences in patient characteristics and BP measurement techniques.

Serum albumin concentration and risk of end-stage renal disease: the REGARDS study.

Background: Serum albumin concentration is a commonly available biomarker with prognostic value in many disease states. It is uncertain whether serum albumin concentrations are associated with incident end-stage renal disease (ESRD) independently of urine albumin-to-creatinine ratio (ACR). Methods: A longitudinal evaluation was performed of a population-based community-living cohort from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study. Participants were ≥45 years of age at study entry and had serum albumin, creatinine, cystatin C and spot urine ACR measured at the baseline visit (n = 19 633). Estimated glomerular filtration rate (eGFR) was from the Chronic Kidney Disease Epidemiology Collaboration combined creatinine-cystatin C equation. Baseline serum albumin concentration was the predictor variable, and hazard ratios (HRs) for incident ESRD (from US Renal Data System linkage) were calculated in sequentially adjusted models. Results: Age at study entry was 63.9 ± 9.7 years, 62% of the participants were female and 40% were black. Mean eGFR at baseline was 83.3 ± 20.8 mL/min/1.73 m2. Over a median 8-year follow-up, 1.2% (n = 236) developed ESRD. In models adjusted for baseline eGFR, ACR and other ESRD risk factors, the HR for incident ESRD was 1.16 [95% confidence interval (CI) 1.01-1.33] for each standard deviation (0.33 g/dL) lower serum albumin concentration. The HR comparing the lowest (<4 g/dL) and highest quartiles (≥4.4 g/dL) of serum albumin was 1.61 (95% CI 0.98-2.63). Results were qualitatively similar among participants with eGFR <60 and ≥60 mL/min/1.73 m2, and those with and without diabetes. Conclusions: In community-dwelling US adults, lower serum albumin concentration is associated with higher risk of incident ESRD independently of baseline urine ACR, eGFR and other ESRD risk factors.