Gender and race disparities in the prevalence of chronic kidney disease among individuals with hypertension in the United States, 2001-2016.

Background: Chronic kidney disease (CKD) is a common complication among individuals with hypertension. We aimed to identify the prevalence of CKD and the sex and race disparities within the hypertensive population in the United States from 2001-2016. Methods: A total of 16,148 participants with hypertension were included, representing 561,909,480 individuals from the U.S. population between 2001 and 2016, as documented in the National Health and Nutrition Examination Survey. The prevalence of albuminuria and CKD stage were assessed using survey-weighted general linear regression analysis. Heterogeneity in the CKD stage among the hypertensive population, stratified by sex and race, was identified through survey-weighted logistic regression analysis. Results: Overall, the prevalence of albuminuria remained stable (p for trend = 0.3196), and changes in the CKD stage were minimal (p for trend > 0.05) from 2001-2016. In the analysis of CKD stage heterogeneity by sex and race, the prevalence of CKD was higher among women than men and higher among individuals of other races combined than non-Hispanic Whites, but the differences were not statistically significant. Conclusion: The overall CKD stage within the hypertensive population plateaued between 2001 and 2016. Our findings highlight the importance of continuous monitoring and potential refinement of renoprotection strategies in individuals with hypertension to mitigate the persistent burden of CKD and address health disparities among different demographic groups.

Management of chronic kidney disease for Maori in Aotearoa New Zealand: a summary of clinical practice guidelines.

AIMS: The kaupapa of the Caring for Australians and New Zealanders with Kidney Impairment (CARI) Clinical practice guidelines for management of chronic kidney disease for Maori in Aotearoa New Zealand is to provide whanau-centred and evidence-based recommendations to healthcare systems, healthcare providers and healthcare workers. The guidelines include screening, identification, management and system-level responses to chronic kidney disease (CKD) to deliver best practice care to Maori affected by CKD across community, primary and secondary services. METHODS: The guidelines are funded by the Ministry of Health - Manatu Hauora and are written by a panel of Maori and non-Maori clinicians and literacy experts across Aotearoa New Zealand from Kaupapa Maori organisations, general practice and nephrology units using standardised methods. The guidelines methodology included consultation with whanau Maori with lived experience of CKD and primary and secondary care practitioners. Additional guideline development would be required to inform management of CKD for non-Maori in Aotearoa New Zealand. RESULTS: The guidelines provide recommendations about equity, governance and accountability, cultural safety, case management, information systems, social determinants of equity and wellbeing and screening. CONCLUSIONS: Recommendations to health services for Maori with CKD are based on giving effect to Te Tiriti o Waitangi and best practice care to prevent CKD, delaying its progression, treating kidney failure through timely transplantation, delivering in community and providing high-quality symptom management.

Multi-year population-based analysis of Asian patients with acute decompensated heart failure and advanced chronic kidney disease.

BACKGROUND: Data on disparities in outcomes and risk factors in Asian patients with advanced chronic kidney disease admitted for heart failure are scare. METHODS: This was a retrospective cohort study that utilized data from the National Inpatient Sample between January 2016 and December 2019. Patients who had a primary diagnosis of acute decompensated heart failure and a concomitant diagnosis of advanced CKD were included. The primary outcome of interest was in-hospital mortality. Secondary outcomes include hospital cost, length of stay, and other clinical outcomes. Weighted multivariable logistic regression was used to adjust for comorbidities. RESULTS: There were 251,578 cases of ADHF with advanced CKD, out of which 2.6 % were from individuals of Asian ethnicity. Asian patients exhibited a higher burden of comorbidities in comparison to other UREM patients, but a lower burden than White patients. Regardless of differences in comorbidity burden, Asian patients exhibited a higher likelihood of experiencing severe consequences. After adjusting for comorbidies, White (OR:1.11; 95 % CI 1.03-1.20;0.009) patients had higher odds of mortality than Asian patients. However, Blacks (OR: 0.58; 95 % CI 0.53 to 0.63; p < 0.001) and Hispanics (OR: 0.69; 95 % CI 0.62 to 0.78; p < 0.001) had lower odds of mortality. CONCLUSION: This first population-based studies shows that Asian patients with advanced CKD admitted for ADHF have greater comorbidity burden and poorer outcomes Black and Hispanic patients. This data underscores the importance of comprehensive approaches in phenotyping, and ethnic specific interventions.

Renal effects and safety between Asian and non-Asian chronic kidney disease and type 2 diabetes treated with nonsteroidal mineralocorticoid antagonists.

BACKGROUND: Asians bear a heavier burden of chronic kidney disease (CKD), a common comorbidity of type 2 diabetes mellitus (T2DM), than non-Asians. Nonsteroidal mineralocorticoid receptor antagonists (MRAs) have garnered attention for their potential advantages in renal outcomes. Nevertheless, the impact on diverse ethnic groups remains unknown. METHODS: The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang database, and clinical trial registries were searched through August 2023 with the following keywords: nonsteroidal MRAs (finerenone, apararenone, esaxerenone, AZD9977, KBP-5074), CKD, T2DM, and randomized controlled trial (RCT). A random effects model was used to calculate overall effect sizes. RESULTS: Seven RCTs with 14 997 participants were enrolled. Nonsteroidal MRAs reduced urinary albumin to creatinine ratio (UACR) significantly more in Asians than non-Asians: (weighted mean difference [WMD], -0.59, 95% CI, -0.73 to -0.45, p < .01) vs (WMD, -0.29, 95% CI, -0.32 to -0.27, p < .01), respectively. The average decline of estimated glomerular filtration rate (eGFR) was similar in Asians and non-Asians (p > .05). Regarding systolic blood pressure (SBP), nonsteroidal MRAs had a better antihypertension performance in Asians (WMD, -5.12, 95% CI, -5.84 to -4.41, p < .01) compared to non-Asians (WMD, -3.64, 95% CI, -4.38 to -2.89, p < .01). A higher incidence of hyperkalemia and eGFR decrease ≥30% was found in Asians than non-Asians (p < .01). CONCLUSIONS: Nonsteroidal MRAs exhibited significant renal benefits by decreasing UACR and lowering SBP in Asian than that of non-Asian patients with CKD and T2DM, without increase of adverse events except hyperkalemia and eGFR decrease ≥30%.

APOL1-Mediated Kidney Disease.

This JAMA Insights reviews the origin of APOL1 high-risk genetic variants, defines APOL1-mediated kidney disease, and discusses recommendations for screening and management.

Diets high in subsidized foods and chronic kidney disease in Hispanic communities in the United States: the Hispanic Community Health Study/Study of Latinos.

Prior research shows that diets high in government subsidized foods may be associated with cardiometabolic disease risk factors. Our aim was to evaluate the relationship between diets high in subsidized foods and the development of chronic kidney disease (CKD) and other cardiometabolic risk factors in United States (US) Hispanics/Latinos. Using data from 16,172 Hispanics/Latino's living in the United States, we used the Cochran-Armitage test to assess the relationship between subsidized foods in the diets of participants and baseline characteristics. We used survey-weighted Poisson regression models to examine whether intake of subsidized foods was associated with incident CKD or cardiometabolic risk factors. Several baseline characteristics were associated with higher subsidized food scores. Higher subsidized food scores were not associated with incident CKD or cardiometabolic risk factors. These findings may be useful for future researchers, clinicians, and nutritional policy advocates who are interested in the way Hispanic and Latinos consume foods subsidized by the US government and the structural factors that may shape observed dietary and disease patterns.

It matters who you are and where you live: Commonwealth, state and territory policies for access to care for Australians with chronic kidney disease and their caregivers.

OBJECTIVE: To describe how Commonwealth, state and territory policies address access to care for Australians living with chronic kidney disease (CKD) with an emphasis on Aboriginal and Torres Strait Islanders and people residing in rural and remote areas. METHODS: We searched government health department websites for current policies up to March 2022 that addressed access to care for people with CKD. RESULTS: We included 98 policies: 28 were Commonwealth, and 70 were state or territory-based. There was wide variation in the policies for people with CKD in number and type across the jurisdictions. Of CKD specific policies, only three policies were specific for people living with CKD in rural and remote areas and no policies were specific for Aboriginal and Torres Strait Islander people. CONCLUSION: There is a lack of CKD-specific policies addressing access to care for Aboriginal and Torres Strait Islander people and people living in rural and remote communities. IMPLICATIONS FOR PUBLIC HEALTH: Despite the known disparities in the burden of CKD there are few policies addressing CKD disparities for Aboriginal and Torres Strait Islander people and Australians living in rural and remote areas. Policies that specifically address the barriers to accessing care are required to reduce inequities.

Novel genetic markers for chronic kidney disease in a geographically isolated population of Indigenous Australians: Individual and multiple phenotype genome-wide association study.

BACKGROUND: Chronic kidney disease (CKD) is highly prevalent among Indigenous Australians, especially those in remote regions. The Tiwi population has been isolated from mainland Australia for millennia and exhibits unique genetic characteristics that distinguish them from other Indigenous and non-Indigenous populations. Notably, the rate of end-stage renal disease is up to 20 times greater in this population compared to non-Indigenous populations. Despite the identification of numerous genetic loci associated with kidney disease through GWAS, the Indigenous population such as Tiwi remains severely underrepresented and the increased prevalence of CKD in this population may be due to unique disease-causing alleles/genes. METHODS: We used albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) to estimate the prevalence of kidney disease in the Tiwi population (N = 492) in comparison to the UK Biobank (UKBB) (N = 134,724) database. We then performed an exploratory factor analysis to identify correlations among 10 CKD-related phenotypes and identify new multi-phenotype factors. We subsequently conducted a genome-wide association study (GWAS) on all single and multiple phenotype factors using mixed linear regression models, adjusted for age, sex, population stratification, and genetic relatedness between individuals. RESULTS: Based on ACR, 20.3% of the population was at severely increased risk of CKD progression and showed elevated levels of ACR compared to the UKBB population independent of HbA1c. A GWAS of ACR revealed novel association loci in the genes MEG3 (chr14:100812018:T:A), RAB36 (rs11704318), and TIAM2 (rs9689640). Additionally, multiple phenotypes GWAS of ACR, eGFR, urine albumin, and serum creatinine identified a novel variant that mapped to the gene MEIS2 (chr15:37218869:A:G). Most of the identified variants were found to be either absent or rare in the UKBB population. CONCLUSIONS: Our study highlights the Tiwi population's predisposition towards elevated ACR, and the collection of novel genetic variants associated with kidney function. These associations may prove valuable in the early diagnosis and treatment of renal disease in this underrepresented population. Additionally, further research is needed to comprehensively validate the functions of the identified variants/genes.

Unsupervised machine learning method for indirect estimation of reference intervals for chronic kidney disease in the Puerto Rican population.

Reference intervals (RIs) for clinical laboratory values are extremely important for diagnostics and treatment of patients. However, the determination of these ranges is costly and time-consuming. As a result, often different unverified RIs are used in practice for the same analyte and the same range is used for all patients despite evidence that the values are gender, age, and ethnicity dependent. Moreover, the abnormal flags are rudimentary, merely indicating if a value is within the RI. At the same time, clinical lab data generated in the everyday medical practice contains a wealth of information, that given the correct methodology, can help determine the RIs for each specific segment of the population, including populations that suffer from health disparities. In this work, we develop unsupervised machine learning methods, based on Gaussian mixtures, to determine RIs of analytes related to chronic kidney disease, using millions of routine lab results for the Puerto Rican population. We show that the measures are both gender and age dependent and we find evidence for normal age-related organ function deterioration and failure. We also show that the joint distribution of measures improves the diagnostic value of the lab results.

Exploring barriers to living donor kidney transplant for African, Caribbean and Black communities in the Greater Toronto Area, Ontario: a qualitative study protocol.

INTRODUCTION: Living donor (LD) kidney transplant (KT) is the best treatment option for many patients with kidney failure as it improves quality of life and survival compared with dialysis and deceased donor KT. Unfortunately, LDKT is underused, especially among groups marginalised by race and ethnicity. African, Caribbean and Black (ACB) patients are 60%-70% less likely to receive LDKT in Canada compared with white patients. Research from the USA and the UK suggests that mistrust, cultural and generational norms, access, and affordability may contribute to inequities. To date, no Canadian studies have explored the beliefs and behaviours related to LDKT in ACB communities. Research approaches that use a critical, community-based approach can help illuminate broader structural factors that may shape individual beliefs and behaviours. In this qualitative study, we will investigate barriers to accessing LDKT in ACB communities in the Greater Toronto Area, to enhance our understanding of the perspectives and experiences of ACB community members, both with and without lived experience of chronic kidney disease (CKD). METHODS AND ANALYSIS: Hospital-based and community-based recruitment strategies will be used to recruit participants for focus groups and individual interviews. Participants will include self-identified ACB individuals with and without experiences of CKD and nephrology professionals. Collaboration with ACB community partners will facilitate a community-based research approach. Data will be analysed using reflexive thematic analysis and critical race theory. Findings will be revised based on feedback from ACB community partners. ETHICS AND DISSEMINATION: This study has been approved by the University Health Network Research Ethics Board UHN REB file #15-9775. Study findings will contribute to the codevelopment of culturally safe and responsive educational materials to raise awareness about CKD and its treatments and to improve equitable access to high-quality kidney care, including LDKT, for ACB patients.

[Ethnic and age characteristics of the frequency of risk factors chronic kidney disease in elderly and senile people of the Republic of Sakha (Yakutia).]

The study included patients with chronic kidney disease aged 60-89 years, who were divided into three groups by ethnicity (Evens, Yakuts and Russians). By age, all study participants were divided into 2 age groups: elderly (60-74 years old) and senile (75-89 years old). For the first time, ethnic features of the prevalence of risk factors and progression of chronic kidney disease in elderly and senile people of the Republic of Sakha (Yakutia) were revealed on clinical material. At the same time, risk factors are more clearly and fully represented in Russians and Yakuts. The lowest frequency of atherosclerosis and coronary heart disease is observed in Even people, despite the fact that the frequency of bad habits among them is higher. The approach used in this work to the study of risk factors and the occurrence of chronic kidney disease necessitates screening for the prevention of this pathology, depending on ethnicity and age.

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.

Time to Abolish Metrics That Sustain Systemic Racism in Kidney Allocation.

This Viewpoint discusses how the Kidney Donor Profile Index (KDPI) in its current form is not fit to guide kidney allocation because it devalues organ donation by Black donors based on a weak association between donor race and kidney transplant failure.

Progression of chronic kidney disease among black patients attending a tertiary hospital in Johannesburg, South Africa.

BACKGROUND: Chronic kidney disease (CKD) is a major public health issue worldwide and is an important contributor to the overall non-communicable disease burden. Chronic kidney disease is usually asymptomatic, and insidiously and silently progresses to advanced stages in resource limited settings. METHODOLOGY: A prospective longitudinal study was carried out on black patients with CKD attending the kidney outpatient clinic at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) in South Africa, between September 2019 to March 2022. Demographic and clinical data were extracted from the ongoing continuous clinic records, as well as measurements of vital signs and interviews at baseline and at follow up. Patients provided urine and blood samples for laboratory investigations as standard of care at study entry (0) and at 24 months, and were followed up prospectively for two (2) years. Data were descriptively and inferentially entered into REDcap and analysed using STATA version 17, and multivariable logistic regression analysis was used to identify predictors of CKD progression. RESULTS: A total of 312 patients were enrolled into the study, 297 (95.2%) patients completed the study, 10 (3.2%) patients were lost to follow and 5 (1.6%) patients died during the study period. The prevalence of CKD progression was 49.5%, while that of CKD remission was 33% and CKD regression was 17.5%. For patients with CKD progression the median age at baseline was 58 (46-67) years, the median eGFR was 37 (32-51) mL/min/1.73 m2, median urine protein creatinine ratio (uPCR) was 0.038 (0.016-0.82) g/mmol and the median haemoglobin (Hb) was 13.1 (11.7-14.4) g/dl; 95.2% had hypertension, 40.1% patients had diabetes mellitus and 39.5% had both hypertension and diabetes mellitus. Almost half (48.3%) of patients with CKD progression had severely increased proteinuria and 45.6% had anaemia. Variables associated with higher odds for CKD progression after multivariable logistic regression analysis were severely increased proteinuria (OR 32.3, 95% CI 2.8-368.6, P = 0.005), moderately increased proteinuria (OR 23.3, 95% CI 2.6-230.1, P = 0.007), hypocalcaemia (OR 3.8, 95% CI 1.0-14.8, P = 0.047), hyponatraemia (OR 4.5, 95% CI 0.8-23.6, P = 0.042), anaemia (OR 2.1, 95% CI 1.0-4.3, P = 0.048), diabetes mellitus (OR 1.8, 95% CI 0.9-3.6, P = 0.047), elevated HbA1c (OR 1.8, 95% CI 1.2-2.8, P = 0.007) and current smoking (OR 2.8, 95% CI 0.9-8.6, P = 0.049). CONCLUSION: Our study identified a higher prevalence of CKD progression in a prospective longitudinal study of black patients with CKD compared with literature reports. CKD Progression was associated with proteinuria, diabetes mellitus, elevated HbA1c, anaemia, hypocalcaemia, hyponatraemia and current smoking in a cohort of black patients with CKD who had controlled hypertension and diabetes mellitus at baseline.

Cystatin C-Based Equation to Estimate GFR without the Inclusion of Race and Sex.

BACKGROUND: The accuracy of estimation of kidney function with the use of routine metabolic tests, such as measurement of the serum creatinine level, has been controversial. The European Kidney Function Consortium (EKFC) developed a creatinine-based equation (EKFC eGFRcr) to estimate the glomerular filtration rate (GFR) with a rescaled serum creatinine level (i.e., the serum creatinine level is divided by the median serum creatinine level among healthy persons to control for variation related to differences in age, sex, or race). Whether a cystatin C-based EKFC equation would increase the accuracy of estimated GFR is unknown. METHODS: We used data from patients in Sweden to estimate the rescaling factor for the cystatin C level in adults. We then replaced rescaled serum creatinine in the EKFC eGFRcr equation with rescaled cystatin C, and we validated the resulting EKFC eGFRcys equation in cohorts of White patients and Black patients in Europe, the United States, and Africa, according to measured GFR, levels of serum creatinine and cystatin C, age, and sex. RESULTS: On the basis of data from 227,643 patients in Sweden, the rescaling factor for cystatin C was estimated at 0.83 for men and women younger than 50 years of age and 0.83 + 0.005 × (age - 50) for those 50 years of age or older. The EKFC eGFRcys equation was unbiased, had accuracy that was similar to that of the EKFC eGFRcr equation in both White patients and Black patients (11,231 patients from Europe, 1093 from the United States, and 508 from Africa), and was more accurate than the Chronic Kidney Disease Epidemiology Collaboration eGFRcys equation recommended by Kidney Disease: Improving Global Outcomes. The arithmetic mean of EKFC eGFRcr and EKFC eGFRcys further improved the accuracy of estimated GFR over estimates from either biomarker equation alone. CONCLUSIONS: The EKFC eGFRcys equation had the same mathematical form as the EKFC eGFRcr equation, but it had a scaling factor for cystatin C that did not differ according to race or sex. In cohorts from Europe, the United States, and Africa, this equation improved the accuracy of GFR assessment over that of commonly used equations. (Funded by the Swedish Research Council.).

Disparities in absolute cardiovascular risk, metabolic syndrome, hypertension, and other risk factors by income within racial/ethnic groups among middle-aged and older US people.

This cross-sectional study determined income disparities in age-adjusted prevalence and trends of 10-year high absolute cardiovascular disease (CVD) risk, metabolic syndrome, hypertension, diabetes, obesity, chronic kidney disease (CKD), leisure-time physical activity (LTPA), and current tobacco smoking within racial/ethnic groups in the US. National Health and Nutrition Examination Survey 2001-2016 data of 40-79-year-old people were analyzed. Survey periods were grouped as 2001-2006, 2007-2012, and 2013-2016. Race/ethnicity was grouped as non-Hispanic whites, non-Hispanic blacks, and other races/ethnicities. Three equal-sized strata (low-, middle-, and high income) were made from the family income-to-poverty ratio. Of the 25,777 participants (mean age: 55.6 years, 48% males), a majority of the studied prevalence was higher in most survey years among non-Hispanic blacks compared to non-Hispanic whites. Most studied prevalence was also higher among low-income people than middle-/high-income people. Within racial/ethnic groups, the prevalence also differed by income for high CVD risk, metabolic syndrome, hypertension, diabetes, obesity, CKD, LTPA, and tobacco smoking (P < 0.05) in most survey periods. After stratifying by race/ethnicity, the prevalence of many conditions remained disproportionately higher among low- and middle-income people, compared to those with high income during most survey periods in all racial/ethnic groups. These results reveal income in addition to race/ethnicity to be an important correlate of cardiovascular health and underscore the need to consider each when controlling for risk factors.

Association of Diabetic Retinopathy with Chronic Kidney Disease Progression in Latinos with Type 2 Diabetes.

Aims: Diabetes remains a leading cause of blindness and kidney failure in the United States. Latinos are at increased risk for type 2 diabetes, and microvascular complications such as diabetic retinopathy (DR) and chronic kidney disease (CKD). We evaluated the association of DR with decline in kidney function in Latinos with type 2 diabetes with or without CKD in a multispecialty clinic. Methods: This is a retrospective cohort study of 351 self-identified Latino individuals with type 2 diabetes enrolled in the Latino Diabetes Initiative at Joslin Diabetes Center. Baseline demographic factors including age, sex, comorbidities, and laboratory values such as A1c and albuminuria were evaluated as predictors of kidney outcomes. The annualized change in estimated glomerular filtration rate (eGFR) was evaluated with a linear regression model. We used logistic regression to evaluate whether DR was associated with development of rapid progressors (>3 mL/min/y eGFR loss) and 30% change in eGFR per year. Results: DR was present in 39.2% of the cohort with mild nonproliferative DR (NPDR) in 57.1%, moderate to severe NPDR in 27.8%, and proliferative DR in 15.0%. Those with DR had a longer duration of type 2 diabetes (P<.001), higher albuminuria (P=.003), and lower baseline eGFR (P=.001). We found that individuals with moderate to severe NPDR and proliferative DR had a significant decline in GFR (coefficient -6.32; 95% CI, -11.40 to -1.23) and -7.82 (-14.99 to -0.65), compared with individuals without DR. Conclusions: The presence of DR is a marker for increased eGFR loss, emphasizing the need for routine retinal examinations as part of comprehensive diabetes care. Individuals with DR should be considered at high risk for GFR loss.

Race, Interleukin-6, TMPRSS6 Genotype, and Cardiovascular Disease in Patients With Chronic Kidney Disease.

Background Differences in death rate and cardiovascular disease (CVD) between Black and White patients with chronic kidney disease is attributed to sociocultural factors, comorbidities, genetics, and inflammation. Methods and Results We examined the interaction of race, plasma IL-6 (interleukin-6), and TMPRSS6 genotype as determinants of CVD and mortality in 3031 Chronic Renal Insufficiency Cohort study participants. The primary outcomes were all-cause mortality and a composite of incident myocardial infarction, peripheral artery disease, stroke, and heart failure. During the median follow-up of 10 years, Black patients with chronic kidney disease experienced a significantly higher mortality (34% versus 26%) and CVD composite (41% versus 28%) compared with White patients. After adjustment, TMPRSS6 genotype did not associate with the outcomes. The adjusted hazard ratio for mortality (4.11 [2.48-6.80], P<0.001) and CVD composite (2.52 [1.96-3.24], P<0.001) were higher for the highest versus lowest IL-6 quintile. The adjusted hazards for death per 1-quintile increase in IL-6 in White and Black individuals were 1.53 (1.42-1.64) versus 1.29 (1.20-1.38) (P<0.001), respectively. For CVD composite they were 1.61 (1.50-1.74) versus 1.30 (1.22-1.39) (P<0.001), respectively. In Cox proportional hazard models that included IL-6, there was no longer a racial disparity for death (1.01 [0.87-1.16], P=0.92), but significant unexplained mediation remained for CVD (1.24 [1.07-1.43]; P=0.004). Path models that included IL-6, diabetes, and urine albumin to creatinine ratio were able to identify variables responsible for racial disparity in mortality and CVD. Conclusions Racial differences in mortality and CVD among patients with chronic kidney disease could be explained by good-fitting path models that include selected mediator variables including diabetes and plasma IL-6.

Association of Estimated GFR Calculated Using Race-Free Equations With Kidney Failure and Mortality by Black vs Non-Black Race.

Importance: At a given estimated glomerular filtration rate (eGFR), individuals who are Black have higher rates of mortality and kidney failure with replacement therapy (KFRT) compared with those who are non-Black. Whether the recently adopted eGFR equations without race preserve racial differences in risk of mortality and KFRT at a given eGFR is unknown. Objective: To assess whether eGFR equations with and without race and cystatin C document racial differences in risk of KFRT and mortality in populations including Black and non-Black participants. Design, Setting, and Participants: Retrospective individual-level data analysis of 62 011 participants from 5 general population and 3 chronic kidney disease (CKD) US-based cohorts with serum creatinine, cystatin C, and follow-up for KFRT and mortality from 1988 to 2018. Exposures: Chronic Kidney Disease Epidemiology Collaboration equation with serum creatinine (eGFRcr with and without race), cystatin C (eGFRcys without race), or both markers (eGFRcr-cys without race). Main Outcomes and Measures: The prevalence of decreased eGFR at baseline and hazard ratios of KFRT and mortality in Black vs non-Black participants were calculated, adjusted for age and sex. Analyses were performed within each cohort and with random-effect meta-analyses of the models. Results: Among 62 011 participants (20 773 Black and 41 238 non-Black; mean age, 63 years; 53% women), the prevalence ratio (95% CI; percent prevalences) of eGFR less than 60 mL/min/1.73 m2 comparing Black with non-Black participants was 0.98 (95% CI, 0.93-1.03; 11% vs 12%) for eGFRcr with race, 0.95 (95% CI, 0.91-0.98; 17% vs 18%) for eGFRcys, and 1.2 (95% CI, 1.2-1.3; 13% vs 11%) for eGFRcr-cys but was 1.8 (95% CI, 1.7-1.8; 15% vs 9%) for eGFRcr without race. During a mean follow-up of 13 years, 8% and 4% of Black and non-Black participants experienced KFRT and 34% and 39% died, respectively. Decreased eGFR was associated with significantly greater risk of both outcomes for all equations. At an eGFR of 60 mL/min/1.73 m2, the hazard ratios for KFRT comparing Black with non-Black participants were 2.8 (95% CI, 1.6-4.9) for eGFRcr with race, 3.0 (95% CI, 1.5-5.8) for eGFRcys, and 2.8 (95% CI, 1.4-5.4) for eGFRcr-cys vs 1.3 (95% CI, 0.8-2.1) for eGFRcr without race. The 5-year absolute risk differences for KFRT comparing Black with non-Black participants were 1.4% (95% CI, 0.2%-2.6%) for eGFRcr with race, 1.1% (95% CI, 0.2%-1.9%) for eGFRcys, and 1.3% (95% CI, 0%-2.6%) for eGFRcr-cys vs 0.37% (95% CI, -0.32% to 1.05%) for eGFRcr without race. Similar patterns were observed for mortality. Conclusions and Relevance: In this retrospective analysis of 8 US cohorts including Black and non-Black individuals, the eGFR equation without race that included creatinine and cystatin C, but not the eGFR equation without race that included creatinine without cystatin C, demonstrated racial differences in the risk of KFRT and mortality throughout the range of eGFR. The eGFRcr-cys equation may be preferable to the eGFRcr equation without race for assessing racial differences in the risk of KFRT and mortality associated with low eGFR.