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BackgroundThe inclusion of race in equations to estimate the glomerular filtration rate (GFR) has become controversial. Alternative equations that can be used to achieve similar accuracy without the use of race are needed.MethodsIn a large national study involving adults with chronic kidney disease, we conducted cross-sectional analyses of baseline data from 1248 participants for whom data, including the following, had been collected: race as reported by the participant, genetic ancestry markers, and the serum creatinine, serum cystatin C, and 24-hour urinary creatinine levels.ResultsUsing current formulations of GFR estimating equations, we found that in participants who identified as Black, a model that omitted race resulted in more underestimation of the GFR (median difference between measured and estimated GFR, 3.99 ml per minute per 1.73 m2 of body-surface area; 95% confidence interval [CI], 2.17 to 5.62) and lower accuracy (percent of estimated GFR within 10% of measured GFR [P10], 31%; 95% CI, 24 to 39) than models that included race (median difference, 1.11 ml per minute per 1.73 m2; 95% CI, -0.29 to 2.54; P10, 42%; 95% CI, 34 to 50). The incorporation of genetic ancestry data instead of race resulted in similar estimates of the GFR (median difference, 1.33 ml per minute per 1.73 m2; 95% CI, -0.12 to 2.33; P10, 42%; 95% CI, 34 to 50). The inclusion of non-GFR determinants of the serum creatinine level (e.g., body-composition metrics and urinary excretion of creatinine) that differed according to race reported by the participants and genetic ancestry did not eliminate the misclassification introduced by removing race (or ancestry) from serum creatinine-based GFR estimating equations. In contrast, the incorporation of race or ancestry was not necessary to achieve similarly statistically unbiased (median difference, 0.33 ml per minute per 1.73 m2; 95% CI, -1.43 to 1.92) and accurate (P10, 41%; 95% CI, 34 to 49) estimates in Black participants when GFR was estimated with the use of cystatin C.ConclusionsThe use of the serum creatinine level to estimate the GFR without race (or genetic ancestry) introduced systematic misclassification that could not be eliminated even when numerous non-GFR determinants of the serum creatinine level were accounted for. The estimation of GFR with the use of cystatin C generated similar results while eliminating the negative consequences of the current race-based approaches. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.).

BackgroundPatients with chronic kidney disease (CKD) face risks of not only end-stage kidney disease (ESKD), cardiovascular disease (CVD) and death, but also decline in kidney function, quality of life (QOL) and mental and physical well-being. This study describes the multidimensional trajectories of CKD using clinical events, kidney function and patient-reported outcome measures (PROMs). We hypothesized that more advanced CKD stages would associate with more rapid decline in each outcome.MethodsAmong 3939 participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study, we evaluated multidimensional disease trajectories by G- and A-stages of enrollment estimated glomerular filtration rate (eGFR) and albuminuria, respectively. These trajectories included clinical events (ESKD, CVD, heart failure and death), eGFR decline and PROMs [kidney disease QOL (KDQOL) burden, effects and symptoms questionnaires, as well as the 12-item short form mental and physical component summaries]. We also evaluated a group-based multitrajectory model to group participants on the basis of longitudinal PROMs and compared group assignments by enrollment G- and A-stage.ResultsThe mean participant age was 58 years, 45% were women, mean baseline eGFR was 44 mL/min/1.73 m2 and median urine albumin:creatinine ratio was 52 mg/g. The incidence of all clinical events was greater and eGFR decline was faster with more advanced G- and A-stages. While baseline KDQOL and physical component measures were lower with more advanced G- and A-stage of CKD, changes in PROMs were inconsistently related to the baseline CKD stage. Groups formed on PROM trajectories were fairly distinct from existing CKD staging (observed agreement 60.6%) and were associated with the risk of ESKD, CVD, heart failure and death.ConclusionsMore advanced baseline CKD stage was associated with a higher risk of clinical events and faster eGFR decline, and was only weakly related to changes in patient-reported metrics over time.

Rationale & objectiveThe clearance of protein-bound solutes by the proximal tubules is an innate kidney mechanism for removing putative uremic toxins that could exert cardiovascular toxicity in humans. However, potential associations between impaired kidney clearances of secretory solutes and cardiovascular events among patients with chronic kidney disease (CKD) remains uncertain.Study designA multicenter, prospective, cohort study.Setting & participantsWe evaluated 3,407 participants from the Chronic Renal Insufficiency Cohort (CRIC) study.ExposuresBaseline kidney clearances of 8 secretory solutes. We measured concentrations of secretory solutes in plasma and paired 24-hour urine specimens using liquid chromatography-tandem mass spectrometry (LC-MS/MS).OutcomesIncident heart failure, myocardial infarction, and stroke events.Analytical approachWe used Cox regression to evaluate associations of baseline secretory solute clearances with incident study outcomes adjusting for estimated GFR (eGFR) and other confounders.ResultsParticipants had a mean age of 56 years; 45% were women; 41% were Black; and the median estimated glomerular filtration rate (eGFR) was 43 mL/min/1.73 m2. Lower 24-hour kidney clearance of secretory solutes were associated with incident heart failure and myocardial infarction but not incident stroke over long-term follow-up after controlling for demographics and traditional risk factors. However, these associations were attenuated and not statistically significant after adjustment for eGFR.LimitationsExclusion of patients with severely reduced eGFR at baseline; measurement variability in secretory solutes clearances.ConclusionsIn a national cohort study of CKD, no clinically or statistically relevant associations were observed between the kidney clearances of endogenous secretory solutes and incident heart failure, myocardial infarction, or stroke after adjustment for eGFR. These findings suggest that tubular secretory clearance provides little additional information about the development of cardiovascular disease events beyond glomerular measures of GFR and albuminuria among patients with mild-to-moderate CKD.

IntroductionManagement of chronic kidney disease (CKD) entails high medical complexity and often results in high hospitalization burden. There are limited data on the associations of longitudinal hospital utilization patterns with adverse clinical outcomes in individuals with CKD.MethodsWe derived cumulative all-cause hospitalization trajectory groups using latent class trajectory analysis in 3012 participants of the Chronic Renal Insufficiency Cohort (CRIC) Study who were alive and did not reach end-stage kidney disease (ESKD) within 4 years of study entry. Cox proportional hazards models tested the associations between hospitalization trajectory groups and risks of ESKD and death prior to the onset of ESKD (ESKD-censored death).ResultsWithin 4 years of study entry, there were 5658 hospitalizations among 3012 participants. We identified 3 distinct subgroups of individuals with CKD based on cumulative all-cause hospitalization trajectories over 4 years: low-utilizer (n = 1066), intermediate-utilizer (n = 1802), and high-utilizer (n = 144). High-utilizers represented a patient population of lower socioeconomic status who had a greater prevalence of comorbid conditions and lower kidney function compared with intermediate- and low-utilizers. After the 4-year ascertainment period to form the trajectory subgroups, there were 544 ESKD events and 437 ESKD-censored deaths during a median follow-up time of 5.1 years. Compared with low-utilizers, intermediate-utilizers and high-utilizers were at 1.49-fold (95% confidence interval [CI] 1.22-1.84) and 1.75-fold (95% CI 1.20-2.56) higher risk of ESKD in adjusted analyses, respectively. Compared with low-utilizers, intermediate-utilizers and high-utilizers were at 1.48-fold (95% CI 1.17-1.87) and 2.58-fold (95% CI 1.74-3.83) higher risk of ESKD-censored death in adjusted analyses, respectively.ConclusionsTrajectories of cumulative all-cause hospitalization identify subgroups of individuals with CKD who are at high risk of ESKD and death.

BackgroundStudies in the general population suggest that atrial fibrillation (AF) is an independent risk factor for decline in cognitive function, but this relationship has not been examined in adults with chronic kidney disease (CKD). We investigated the association between incident AF and changes in cognitive function over time in this population.Methods and resultsWe studied a subgroup of 3254 adults participating in the Chronic Renal Insufficiency Cohort Study. Incident AF was ascertained by 12-lead electrocardiogram (ECG) obtained at a study visit and/or identification of a hospitalization with AF during follow-up. Cognitive function was assessed biennially using the Modified Mini-Mental State Exam. Linear mixed effects regression was used to evaluate the association between incident AF and longitudinal change in cognitive function. Compared with individuals without incident AF (n = 3158), those with incident AF (n = 96) were older, had a higher prevalence of cardiovascular disease and hypertension, and lower estimated glomerular filtration rate. After median follow-up of 6.8 years, we observed no significant multivariable association between incident AF and change in cognitive function test score.ConclusionIn this cohort of adults with CKD, incident AF was not associated with a decline in cognitive function.

Rationale & objectiveObservational studies have reported a U-shaped association between blood pressure (BP) before a hemodialysis session and death. In contrast, because a linear association between out-of-dialysis-unit BP and death has been reported, home BP may be a better target for treatment. To test the feasibility of this approach, we conducted a pilot trial of treating home versus predialysis BP in hemodialysis patients.Study designA 4-month, parallel, randomized, controlled trial.Settings & participants50 prevalent hemodialysis patients in San Francisco and Seattle. Participants were randomly assigned using 1:1 block randomization, stratified by site.InterventionsTo target home systolic BP (SBP) of 100-200mm Hg; 0.2% vs 0%) or low (defined as

BackgroundOur aims were to assess whether arterial stiffness is associated with a higher risk for kidney dysfunction among persons without chronic kidney disease (CKD).MethodsWe analyzed data from the national health checkup system in Japan; for our analyses, we selected records of individuals who completed assessments of cardio-ankle vascular index (CAVI) and kidney function from 2005 to 2016. We excluded participants who had CKD at baseline, defined as the presence of proteinuria or estimated glomerular filtration rate (eGFR)

Rationale & objectiveAmong individuals with chronic kidney disease (CKD), poor self-reported health is associated with adverse outcomes including hospitalization and death. We sought to examine the association between health-related quality-of-life (HRQoL) and depressive symptoms in advanced CKD and subsequent access to the kidney transplant waiting list.Study designProspective cohort study.Setting & population1,676 Chronic Renal Insufficiency Cohort (CRIC) study participants with estimated glomerular filtration rates ≤ 30 mL/min/1.73 m2 at study entry or during follow-up.ExposuresHRQoL ascertained by 5 scales of the Kidney Disease Quality of Life-36 Survey (Physical Component Summary [PCS], Mental Component Summary, Symptoms, Burdens, and Effects), with higher scores indicating better HRQoL, and depressive symptoms ascertained using the Beck Depression Inventory.OutcomesTime to kidney transplant wait-listing and time to pre-emptive wait-listing.Analytic approachTime-to-event analysis using Cox proportional hazards regression.ResultsDuring a median follow-up of 5.1 years, 652 (39%) participants were wait-listed, of whom 304 were preemptively wait-listed. Adjusted for demographics, comorbid conditions, estimated glomerular filtration rate slope, and cognitive function, participants with the highest scores on the Burden and Effects scales, respectively, had lower rates of wait-listing than those with the lowest scores on the Burden (wait-listing adjusted hazard ratio [aHR], 0.70; 95% CI, 0.57-0.85; P

Rationale & objectiveStudies using a single measurement of fibroblast growth factor 23 (FGF-23) suggest that elevated FGF-23 levels are associated with increased risk for requirement for kidney replacement therapy (KRT) in patients with chronic kidney disease. However, the data do not account for changes in FGF-23 levels as kidney disease progresses.Study designCase-cohort study.Setting & participantsTo evaluate the association between serial FGF-23 levels and risk for requiring KRT, our primary analysis included 1,597 individuals in the Chronic Renal Insufficiency Cohort Study who had up to 5 annual measurements of carboxy-terminal FGF-23. There were 1,135 randomly selected individuals, of whom 266 initiated KRT, and 462 individuals who initiated KRT outside the random subcohort.ExposureSerial FGF-23 measurements and FGF-23 trajectory group membership.OutcomesIncident KRT.Analytical approachTo handle time-dependent confounding, our primary analysis of time-updated FGF-23 levels used time-varying inverse probability weighting in a discrete time failure model. To compare our results with prior data, we used baseline and time-updated FGF-23 values in weighted Cox regression models. To examine the association of FGF-23 trajectory subgroups with risk for incident KRT, we used weighted Cox models with FGF-23 trajectory groups derived from group-based trajectory modeling as the exposure.ResultsIn our primary analysis, the HR for the KRT outcome per 1 SD increase in the mean of natural log-transformed (ln)FGF-23 in the past was 1.94 (95% CI, 1.51-2.49). In weighted Cox models using baseline and time-updated values, elevated FGF-23 level was associated with increased risk for incident KRT (HRs per 1 SD ln[FGF-23] of 1.18 [95% CI, 1.02-1.37] for baseline and 1.66 [95% CI, 1.49-1.86] for time-updated). Membership in the slowly and rapidly increasing FGF-23 trajectory groups was associated with ∼3- and ∼21-fold higher risk for incident KRT compared to membership in the stable FGF-23 trajectory group.LimitationsResidual confounding and lack of intact FGF-23 values.ConclusionsIncreasing FGF-23 levels are independently associated with increased risk for incident KRT.

Rationale & objectivesFew studies have investigated racial disparities in survival among dialysis patients in a manner that considers risk factors and mortality during the phase of kidney disease before maintenance dialysis. Our objective was to explore racial variations in survival among dialysis patients and relate them to racial differences in comorbid conditions and rates of death in the setting of kidney disease not yet requiring dialysis therapy.Study designRetrospective cohort study.Settings & participants3,288 black and white participants in the Chronic Renal Insufficiency Cohort (CRIC), none of whom were receiving dialysis at enrollment.ExposureRace.OutcomeMortality.Analytic approachCox proportional hazards regression was used to examine the association between race and mortality starting at: (1) time of dialysis initiation and (2) entry into the CRIC.ResultsDuring 7.1 years of median follow-up, 678 CRIC participants started dialysis. Starting from the time of dialysis initiation, blacks had lower risk for death (unadjusted HR, 0.67; 95% CI, 0.51-0.87) compared with whites. Starting from baseline CRIC enrollment, the strength of the association between some risk factors and dialysis was notably stronger for whites than blacks. For example, the HR for dialysis onset in the presence (vs absence) of heart failure at CRIC enrollment was 1.30 (95% CI, 1.01-1.68) for blacks versus 2.78 (95% CI, 1.90-4.50) for whites, suggesting differential severity of these risk factors by race. When we included deaths occurring both before and after dialysis, risk for death was higher among blacks (vs whites) starting from CRIC enrollment (HR, 1.41; 95% CI, 1.22-1.64), but this finding was attenuated in adjusted models (HR, 1.08; 95% CI, 0.91-1.28).LimitationsResidual confounding.ConclusionsThe apparent survival advantage among blacks over whites treated with dialysis may be attributed to selected transition of a subset of whites with more severe comorbid conditions onto dialysis.

BackgroundObservational studies relying on clinically obtained data have shown that acute kidney injury (AKI) is linked to accelerated chronic kidney disease (CKD) progression. However, prior reports lacked uniform collection of important confounders such as proteinuria and pre-AKI kidney function trajectory, and may be susceptible to ascertainment bias, as patients may be more likely to undergo kidney function testing after AKI.MethodsWe studied 444 adults with CKD who participated in the prospective Chronic Renal Insufficiency Cohort (CRIC) Study and were concurrent members of a large integrated healthcare delivery system. We estimated glomerular filtration rate (eGFR) trajectories using serum creatinine measurements from (i) the CRIC research protocol (yearly) and (ii) routine clinical care. We used linear mixed effects models to evaluate the associations of AKI with acute absolute change in eGFR and post-AKI eGFR slope, and explored whether these varied by source of creatinine results. Models were adjusted for demographic characteristics, diabetes status and albuminuria.ResultsDuring median follow-up of 8.5 years, mean rate of eGFR loss was -0.31 mL/min/1.73 m2/year overall, and 73 individuals experienced AKI (55% Stage 1). A significant interaction existed between AKI and source of serum creatinine for acute absolute change in eGFR level after discharge; in contrast, AKI was independently associated with a faster rate of eGFR decline (mean additional loss of -0.67 mL/min/1.73 m2/year), which was not impacted by source of serum creatinine.ConclusionsAKI is independently associated with subsequent steeper eGFR decline regardless of the serum creatinine source used, but the strength of association is smaller than observed in prior studies after taking into account key confounders such as pre-AKI eGFR slope and albuminuria.

Background We tested associations of cardiac biomarkers of myocardial stretch, injury, inflammation, and fibrosis with the risk of incident atrial fibrillation (AF) in a prospective study of chronic kidney disease patients. Methods and Results The study sample was 3053 participants with chronic kidney disease in the multicenter CRIC (Chronic Renal Insufficiency Cohort) study who were not identified as having AF at baseline. Cardiac biomarkers, measured at baseline, were NT-proBNP (N-terminal pro-B-type natriuretic peptide), high-sensitivity troponin T, galectin-3, growth differentiation factor-15, and soluble ST-2. Incident AF ("AF event") was defined as a hospitalization for AF. During a median follow-up of 8 years, 279 (9%) participants developed a new AF event. In adjusted models, higher baseline log-transformed NT-proBNP (N-terminal pro-B-type natriuretic peptide) was associated with incident AF (adjusted hazard ratio [HR] per SD higher concentration: 2.11; 95% CI, 1.75, 2.55), as was log-high-sensitivity troponin T (HR 1.42; 95% CI, 1.20, 1.68). These associations showed a dose-response relationship in categorical analyses. Although log-soluble ST-2 was associated with AF risk in continuous models (HR per SD higher concentration 1.35; 95% CI, 1.16, 1.58), this association was not consistent in categorical analyses. Log-galectin-3 (HR 1.05; 95% CI, 0.91, 1.22) and log-growth differentiation factor-15 (HR 1.16; 95% CI, 0.96, 1.40) were not significantly associated with incident AF. Conclusions We found strong associations between higher NT-proBNP (N-terminal pro-B-type natriuretic peptide) and high-sensitivity troponin T concentrations, and the risk of incident AF in a large cohort of participants with chronic kidney disease. Increased atrial myocardial stretch and myocardial cell injury may be implicated in the high burden of AF in patients with chronic kidney disease.

RATIONALE & OBJECTIVE:Coronary artery calcification (CAC) is prevalent among patients with chronic kidney disease (CKD) and increases risks for cardiovascular disease events and mortality. We hypothesized that a novel serum measure of calcification propensity is associated with CAC among patients with CKD stages 2 to 4. STUDY DESIGN:Prospective cohort study. SETTING & PARTICIPANTS:Participants from the Chronic Renal Insufficiency Cohort (CRIC) Study with baseline (n=1,274) and follow-up (n=780) CAC measurements. PREDICTORS:Calcification propensity, quantified as transformation time (T50) from primary to secondary calciprotein particles, with lower T50 corresponding to higher calcification propensity. Covariates included age, sex, race/ethnicity, clinical site, estimated glomerular filtration rate, proteinuria, diabetes, systolic blood pressure, number of antihypertensive medications, current smoking, history of cardiovascular disease, total cholesterol level, and use of statin medications. OUTCOMES:CAC prevalence, severity, incidence, and progression. ANALYTICAL APPROACH:Multivariable-adjusted generalized linear models. RESULTS:At baseline, 824 (65%) participants had prevalent CAC. After multivariable adjustment, T50 was not associated with CAC prevalence but was significantly associated with greater CAC severity among participants with prevalent CAC: 1-SD lower T50 was associated with 21% (95% CI, 6%-38%) greater CAC severity. Among 780 participants followed up an average of 3 years later, 65 (20%) without baseline CAC developed incident CAC, while 89 (19%) with baseline CAC had progression, defined as annual increase≥100 Agatston units. After multivariable adjustment, T50 was not associated with incident CAC but was significantly associated with CAC progression: 1-SD lower T50 was associated with 28% (95% CI, 7%-53%) higher risk for CAC progression. LIMITATIONS:Potential selection bias in follow-up analyses; inability to distinguish intimal from medial calcification. CONCLUSIONS:Among patients with CKD stages 2 to 4, higher serum calcification propensity is associated with more severe CAC and CAC progression.

RATIONALE & OBJECTIVE:Traditional risk estimates for atherosclerotic vascular disease (ASVD) and death may not perform optimally in the setting of chronic kidney disease (CKD). We sought to determine whether the addition of measures of inflammation and kidney function to traditional estimation tools improves prediction of these events in a diverse cohort of patients with CKD. STUDY DESIGN:Observational cohort study. SETTING & PARTICIPANTS:2,399 Chronic Renal Insufficiency Cohort (CRIC) Study participants without a history of cardiovascular disease at study entry. PREDICTORS:Baseline plasma levels of biomarkers of inflammation (interleukin 1β [IL-1β], IL-1 receptor antagonist, IL-6, tumor necrosis factor α [TNF-α], transforming growth factor β, high-sensitivity C-reactive protein, fibrinogen, and serum albumin), measures of kidney function (estimated glomerular filtration rate [eGFR] and albuminuria), and the Pooled Cohort Equation probability (PCEP) estimate. OUTCOMES:Composite of ASVD events (incident myocardial infarction, peripheral arterial disease, and stroke) and death. ANALYTICAL APPROACH:Cox proportional hazard models adjusted for PCEP estimates, albuminuria, and eGFR. RESULTS:During a median follow-up of 7.3 years, 86, 61, 48, and 323 participants experienced myocardial infarction, peripheral arterial disease, stroke, or death, respectively. The 1-decile greater levels of IL-6 (adjusted HR [aHR], 1.12; 95% CI, 1.08-1.16; P

Rationale & objectiveAbnormal cardiac structure and function are common in chronic kidney disease (CKD) and end-stage renal disease (ESRD) and linked with mortality and heart failure. We examined changes in echocardiographic measures during the transition from CKD to ESRD and their associations with post-ESRD mortality.Study designProspective study.Setting & participantsWe studied 417 participants with CKD in the Chronic Renal Insufficiency Cohort (CRIC) who had research echocardiograms during CKD and ESRD.PredictorWe measured change in left ventricular mass index, left ventricular ejection fraction (LVEF), diastolic relaxation (normal, mildly abnormal, and moderately/severely abnormal), left ventricular end-systolic (LVESV), end-diastolic (LVEDV) volume, and left atrial volume from CKD to ESRD.OutcomesAll-cause mortality after dialysis therapy initiation.Analytical approachCox proportional hazard models were used to test the association of change in each echocardiographic measure with postdialysis mortality.ResultsOver a mean of 2.9 years between pre- and postdialysis echocardiograms, there was worsening of mean LVEF (52.5% to 48.6%; P

Patients with chronic kidney diseases (CKDs) are at risk for further loss of kidney function and death, which occur despite reasonable blood pressure treatment. To determine whether arterial stiffness influences CKD progression and death, independent of blood pressure, we conducted a prospective cohort study of CKD patients enrolled in the CRIC study (Chronic Renal Insufficiency Cohort). Using carotid-femoral pulse wave velocity (PWV), we examined the relationship between PWV and end-stage kidney disease (ESRD), ESRD or halving of estimated glomerular filtration rate, or death from any cause. The 2795 participants we enrolled had a mean age of 60 years, 56.4% were men, 47.3% had diabetes mellitus, and the average estimated glomerular filtration rate at entry was 44.4 mL/min per 1.73 m2 During follow-up, there were 504 ESRD events, 628 ESRD or halving of estimated glomerular filtration rate events, and 394 deaths. Patients with the highest tertile of PWV (>10.3 m/s) were at higher risk for ESRD (hazard ratio [95% confidence interval], 1.37 [1.05-1.80]), ESRD or 50% decline in estimated glomerular filtration rate (hazard ratio [95% confidence interval], 1.25 [0.98-1.58]), or death (hazard ratio [95% confidence interval], 1.72 [1.24-2.38]). PWV is a significant predictor of CKD progression and death in people with impaired kidney function. Incorporation of PWV measurements may help define better the risks for these important health outcomes in patients with CKDs. Interventions that reduce aortic stiffness deserve study in people with CKD.

BackgroundFew studies have investigated the changes in weight that may occur over time among adults with the progression of chronic kidney disease (CKD). Whether such weight changes are independently associated with death after the onset of end-stage renal disease has also not been rigorously examined.Study designProspective cohort study.Setting & participantsWe studied 3,933 participants of the Chronic Renal Insufficiency Cohort (CRIC) Study, a longitudinal cohort of patients with CKD. We also performed similar analyses among 1,067 participants of the African American Study of Kidney Disease and Hypertension (AASK).PredictorsEstimated glomerular filtration rate (eGFR) and weight change during CKD.OutcomeWeight and all-cause mortality after dialysis therapy initiation.ResultsDuring a median follow-up of 5.7 years in CRIC, weight change was not linear. Weight was stable until cystatin C-based eGFR (eGFRcys) decreased to 5% annualized weight loss after eGFR decreased to

ObjectiveTo investigate the effect of LPA gene variants and renal function on lipoprotein(a) [Lp(a)] levels in people with chronic kidney disease and determine the association between elevated Lp(a) and myocardial infarction and death in this setting.Approach and resultsThe CRIC Study (Chronic Renal Insufficiency Cohort) is an ongoing prospective study of 3939 participants with chronic kidney disease. In 3635 CRIC participants with genotype data, carriers of the rs10455872 or rs6930542 variants had a higher median Lp(a) level (mg/dL) compared with noncarriers (73 versus 23; P61.3. There were 315 myocardial infarctions and 822 deaths during a median follow-up of 7.5 years. The second quartile had the lowest event rate. After adjusting for potential confounders and using a Cox proportional hazards model, the highest quartile of Lp(a) was associated with increased risk of myocardial infarction (hazard ratio, 1.49; 95% confidence interval, 1.05-2.11), death (hazard ratio, 1.28; 95% confidence interval, 1.05-1.57), and the composite outcome (hazard ratio, 1.29; 95% confidence interval, 1.07-1.56) compared with the second quartile of Lp(a).ConclusionsAmong adults with chronic kidney disease, elevated Lp(a) is independently associated with myocardial infarction and death. Future studies exploring pharmacological Lp(a) reduction in this population are warranted.