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Background: Alpha globin is expressed in the endothelial cells of human resistance arteries where it binds to endothelial nitric oxide synthase and limits release of the vasodilator nitric oxide. Genomic deletion of the alpha globin gene (HBA) is common among Black Americans and could lead to increased endothelial nitric oxide signaling and reduced risk of hypertension., Methods: Community-dwelling US adults aged 45 years or older were enrolled and examined from 2003 to 2007, followed by telephone every 6 months, and reexamined from 2013 to 2016. At both visits, trained personnel performed standardized, in-home blood pressure measurements and pill bottle review. Prevalent hypertension was defined as systolic blood pressure ≥ 140mmHg or diastolic blood pressure ≥ 90mmHg or anti-hypertensive medication use. Droplet digital PCR was used to determine HBA copy number. The associations of HBA copy number with prevalent hypertension, resistant hypertension, and incident hypertension were estimated using multivariable regression., Results: Among 9,684 Black participants, 7,439 (77%) had hypertension at baseline and 1,044 of those had treatment-resistant hypertension. 1,000 participants were not hypertensive at baseline and participated in a follow up visit; 517 (52%) developed hypertension over median 9.2 years follow-up. Increased HBA copy number was not associated with prevalent hypertension (PR = 1.00; 95%CI 0.98,1.02), resistant hypertension (PR = 0.95; 95%CI 0.86,1.05), or incident hypertension (RR = 0.96; 95%CI 0.86,1.07)., Conclusions: There were no associations between increased HBA copy number and risk of hypertension. These findings suggest that variation in alpha globin gene copy number does not modify the risk of hypertension among Black American adults., Competing Interests: DISCLOSURES Dr. Gutierrez discloses receiving grant funding and consulting fees from Akebia Therapeutics; grant funding and consulting fees from Amgen; grant funding from GlaxoSmithKline; and consulting fees Reata, AstraZeneca, and Ardelyx; and serving on the Data Monitoring Committee for QED Therapeutics. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Introduction: Tubulointerstitial damage in diabetes and chronic kidney disease (CKD) is poorly captured by estimated glomerular filtration rate (eGFR) and albuminuria. Urine biomarkers of kidney health may better elucidate disease progression in persons with diabetes and CKD., Methods: Per case-cohort design, we randomly selected a subcohort of 560 study participants of the REasons for Geographic And Racial Differences in Stroke (REGARDS) study from 1092 adults with diabetes and baseline eGFR <60 ml/min per 1.73 m 2 and registered a total of 161 end-stage kidney disease (ESKD) cases ( n  = 93 from the subcohort; n  = 68 from outside the subcohort) during 4.3 ± 2.7 years mean follow-up. We measured urine biomarkers of kidney tubule injury (kidney injury molecule-1 [KIM-1]), inflammation and fibrosis (monocyte chemoattractant protein-1 [MCP-1]), repair (chitinase-3-like protein 1 [YKL-40]), and tubule function, including reabsorption (alpha-1-microglobulin [α1m]) and synthetic capacity (epidermal growth factor [EGF] and uromodulin [UMOD]). Weighted Cox regression models estimated ESKD risk adjusting for demographics, ESKD risk factors, and baseline eGFR and urine albumin. Least absolute shrinkage and selection operator (LASSO) regression identified a subset of biomarkers most strongly associated with ESKD., Results: At baseline, subcohort participants had mean age of 70 ± 9 years, mean eGFR of 40 ±13 ml/min per 1.73 m 2 , and median urine albumin-to-creatinine ratio of 33 (interquartile range 10-213) mg/g. Adjusting for baseline eGFR and albuminuria, each 2-fold higher urine KIM-1 (hazard ratio = 1.43 [95% CI: 1.17-1.75]), α1m (hazard ratio = 1.47 [1.19-1.82]), and MCP-1 (hazard ratio = 1.27 [1.06-1.53]) were independently associated with ESKD. LASSO retained KIM-1 and α1m for associations with ESKD., Conclusion: Among adults with diabetes and eGFR <60 ml/min per 1.73 m 2 , higher urine KIM-1, α1m, and MCP-1 are independently associated with incident ESKD, providing insight into kidney disease progression in persons with diabetes and CKD., (© 2022 International Society of Nephrology. Published by Elsevier Inc.)

Introduction: Earlier identification of individuals at high risk of chronic kidney disease (CKD) may facilitate improved risk factor mitigation., Methods: We evaluated the association of novel plasma biomarkers with incident CKD using a case-cohort design in participants without diabetes and with baseline estimated glomerular filtration rate (eGFR) ≥ 60 ml/min per 1.73 m 2 in the Multi-Ethnic Study of Atherosclerosis (MESA) and Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohorts. Incident CKD was defined as development of eGFR < 60 ml/min per 1.73 m 2 and ≥40% decline in eGFR from baseline. We measured plasma markers of inflammation/fibrosis-soluble tumor necrosis factor receptors (TNFRs) 1 and 2 (TNFR-1 and TNFR-2), monocyte chemotactic protein-1 (MCP-1), chitinase 3-like protein 1 (YKL-40), and soluble urokinase-type plasminogen activator receptor (suPAR)-and tubular injury (kidney injury molecule 1 [KIM-1]). Cox regression models weighted for the case-cohort design were used to estimate hazard ratios (HRs) of incident CKD after adjustment for CKD risk factors, eGFR, and albuminuria., Results: In MESA (median follow-up of 9.2 years), there were 497 individuals in the random subcohort and 163 incident CKD cases. In REGARDS (median follow-up of 9.4 years), there were 497 individuals in the random subcohort and 497 incident CKD cases. Each 2-fold higher plasma KIM-1 (adjusted HR 1.38 [95% CI 1.05-1.81]), suPAR (1.96 [1.10-3.49]), TNFR-1 (1.65 [1.04-2.62]), TNFR-2 (2.02 [1.21-3.38]), and YKL-40 (1.38 [1.09-1.75]) concentrations were associated with incident CKD in MESA. In REGARDS, TNFR-1 (1.99 [1.43-2.76]) and TNFR-2 (1.76 [1.22-2.54]) were associated with incident CKD., Conclusion: Plasma concentrations of soluble TNFR-1 and TNFR-2 are consistently associated with incident CKD in nondiabetic community-living individuals in MESA and REGARDS., (© 2022 International Society of Nephrology. Published by Elsevier Inc.)

Background: Elevated Fibroblast Growth Factor-23 (FGF23) levels have been associated with greater left ventricular mass (LVM) and heart failure. Whether higher FGF23 is associated with higher LVH prevalence and longitudinal changes in LVM and myocardial strain in middle-aged adults without cardiovascular disease (CVD) or chronic kidney disease (CKD) is unknown., Methods: We studied 3,113 adults without CVD at baseline participating in the Year 25 (2010-2011) follow-up exam of the Coronary Artery Risk Development in Young Adults (CARDIA) study. We studied the association of Year 25 c-terminal FGF23 concentrations with indexed LVM (LVMI=LVM/height 2.7 ), LVH and myocardial strain as assessed by speckle tracking strain echocardiography. Among the 2,758 (88.6%) participants who returned for the Year 30 examination, we also investigated the association of Year 25 FGF23 with 5 Year change in LVMI, strain parameters and incident LVH., Results: The mean age was 50.0 (±3.6) years, 56.8% were female, 45.7% were Black and 6.4% had CKD. There was 6.0% LVH prevalence at Year 25. Mean 5 Year change in LVMI was 5.3 (±7.7) grams/meter. In multivariable models, FGF23 in the highest quartile was associated with greater odds of LVH at Year 25 compared to lower quartiles. [Odds Ratio 95% CI: 1.81 (1.28, 2.58)] with similar findings after exclusion of participants with CKD. There was no interaction between FGF23 and race (P = .18) or sex (P = .80). There was no association between FGF23 and global longitudinal strain. There was no association between FGF23 and 5 Year change in LVMI. There was no association between higher FGF23 and 5 year incident LVH., Conclusions: In a middle-aged adult population without known CVD or CKD, higher FGF23 was associated with greater odds of LVH, but not with greater increases in LVM over time. Further study is needed to elucidate whether FGF23 is a risk marker for underlying LVH or a mechanism for increased LVM over time in younger and middle-aged adult populations without CKD., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Acute kidney injury (AKI) remains a significant clinical problem through its diverse etiologies, the challenges of robust measurements of injury and recovery, and its progression to chronic kidney disease (CKD). Bridging the gap in our knowledge of this disorder requires bringing together not only the technical resources for research but also the investigators currently endeavoring to expand our knowledge and those who might bring novel ideas and expertise to this important challenge. The University of Alabama at Birmingham-University of California-San Diego O'Brien Center for Acute Kidney Injury Research brings together technical expertise and programmatic and educational efforts to advance our knowledge in these diverse issues and the required infrastructure to develop areas of novel exploration. Since its inception in 2008, this O'Brien Center has grown its impact by providing state-of-the-art resources in clinical and preclinical modeling of AKI, a bioanalytical core that facilitates measurement of critical biomarkers, including serum creatinine via LC-MS/MS among others, and a biostatistical resource that assists from design to analysis. Through these core resources and with additional educational efforts, our center has grown its investigator base to include >200 members from 51 institutions. Importantly, this center has translated its pilot and catalyst funding program with a $37 return per dollar invested. Over 500 publications have resulted from the support provided with a relative citation ratio of 2.18 ± 0.12 (iCite). Through its efforts, this disease-centric O'Brien Center is providing the infrastructure and focus to help the development of the next generation of researchers in the basic and clinical science of AKI. This center creates the promise of the application at the bedside of the advances in AKI made by current and future investigators.

Background: Adults who have experienced multiple cardiovascular disease (CVD) events have a very high risk for additional events. Diabetes and chronic kidney disease (CKD) are each associated with an increased risk for recurrent CVD events following a myocardial infarction (MI)., Methods: We compared the risk for recurrent CVD events among US adults with health insurance who were hospitalized for an MI between 2014 and 2017 and had (1) CVD prior to their MI but were free from diabetes or CKD (prior CVD), and those without CVD prior to their MI who had (2) diabetes only, (3) CKD only and (4) both diabetes and CKD. We followed patients from hospital discharge through December 31, 2018 for recurrent CVD events including coronary, stroke, and peripheral artery events., Results: Among 162,730 patients, 55.2% had prior CVD, and 28.3%, 8.3%, and 8.2% had diabetes only, CKD only, and both diabetes and CKD, respectively. The rate for recurrent CVD events per 1000 person-years was 135 among patients with prior CVD and 110, 124 and 171 among those with diabetes only, CKD only and both diabetes and CKD, respectively. Compared to patients with prior CVD, the multivariable-adjusted hazard ratio for recurrent CVD events was 0.92 (95%CI 0.90-0.95), 0.89 (95%CI: 0.85-0.93), and 1.18 (95%CI: 1.14-1.22) among those with diabetes only, CKD only, and both diabetes and CKD, respectively., Conclusion: Following MI, adults with both diabetes and CKD had a higher risk for recurrent CVD events compared to those with prior CVD without diabetes or CKD.

Objectives: Fibroblast growth factor (FGF)-23 is a key regulator of mineral metabolism and has been linked with left ventricular hypertrophy in animal models. Most existing epidemiologic studies evaluated a C-terminal FGF23 assay which measures both the intact (active) hormone and inactive fragments. The relationship of intact FGF23 with cause-specific mortality is unknown., Design: Prospective analyses of data from Health, Aging, & Body Composition (HABC) study., Setting: Community-living adults aged 70 to 79 years with longitudinal follow up., (© 2021 The American Geriatrics Society.)

Purpose: Lifestyle changes associated with end-stage renal disease may be a factor in depression and quality of life (QOL) for patients receiving hemodialysis. This cross-sectional study examined the relationship between nutritional status, QOL, and depression in 124 hemodialysis patients., Methods: Nutritional markers included serum albumin, normalized protein catabolic rate (nPCR), body mass index (BMI), body fat percentage, and daily protein intake. Physical and Mental dimension scores of the Kidney Disease QOL-Short Form (KDQOL-SF), and the Center for Epidemiological Studies of Depression (CESD) survey were used to measure QOL and depression, respectively. Data were analyzed using regression analyses. Measures of effect size were used for interpretation., Results: Nutritional status indicators explained a moderate amount of the variability of the Physical dimension of QOL (crude R 2  = .14, covariate-adjusted ΔR 2  = .06) but had weak explanatory ability for the Mental dimension of QOL (crude R 2  = .05, covariate-adjusted ΔR 2  = .02) and CESD (crude R 2  = .02, covariate-adjusted ΔR 2  = .005). Additional findings suggested the presence of non-linear relationships between protein intake and both the Physical and Mental QOL dimension scores. Longer dialysis vintage was also correlated with lower psychosocial patient outcomes., Conclusion: While nutritional status is an important element in predicting hemodialysis patient outcomes, its relationship to depression and QOL, in this sample, demonstrated only moderate explanatory ability. However, dialysis vintage and level of education had a significant relationship with depression and QOL. These findings suggest that patients with longer dialysis vintage and limited health literacy require unique plans of care. Future studies aimed at understanding the interrelationships between non-modifiable patient characteristics and psychosocial outcomes are imperative.

Background: Although diabetic kidney disease is the leading cause of ESKD in the United States, identifying those patients who progress to ESKD is difficult. Efforts are under way to determine if plasma biomarkers can help identify these high-risk individuals., Methods: In our case-cohort study of 894 Chronic Renal Insufficiency Cohort Study participants with diabetes and an eGFR of <60 ml/min per 1.73 m 2 at baseline, participants were randomly selected for the subcohort; cases were those patients who developed progressive diabetic kidney disease (ESKD or 40% eGFR decline). Using a multiplex system, we assayed plasma biomarkers related to tubular injury, inflammation, and fibrosis (KIM-1, TNFR-1, TNFR-2, MCP-1, suPAR, and YKL-40). Weighted Cox regression models related biomarkers to progression of diabetic kidney disease, and mixed-effects models estimated biomarker relationships with rate of eGFR change., Results: Median follow-up was 8.7 years. Higher concentrations of KIM-1, TNFR-1, TNFR-2, MCP-1, suPAR, and YKL-40 were each associated with a greater risk of progression of diabetic kidney disease, even after adjustment for established clinical risk factors. After accounting for competing biomarkers, KIM-1, TNFR-2, and YKL-40 remained associated with progression of diabetic kidney disease; TNFR-2 had the highest risk (adjusted hazard ratio, 1.61; 95% CI, 1.15 to 2.26). KIM-1, TNFR-1, TNFR-2, and YKL-40 were associated with rate of eGFR decline., Conclusions: Higher plasma levels of KIM-1, TNFR-1, TNFR-2, MCP-1, suPAR, and YKL-40 were associated with increased risk of progression of diabetic kidney disease; TNFR-2 had the highest risk after accounting for the other biomarkers. These findings validate previous literature on TNFR-1, TNFR-2, and KIM-1 in patients with prevalent CKD and provide new insights into the influence of suPAR and YKL-40 as plasma biomarkers that require validation., (Copyright © 2021 by the American Society of Nephrology.)

Introduction: Chronic kidney disease (CKD) is greatly affected by social determinants of health. Whether low educational attainment is associated with incident CKD in young adults is unclear., Methods: We evaluated the association of education with incident CKD in 3139 Coronary Artery Risk Development in Young Adults participants. We categorized education into low (high school and less), medium (college), and high (master's and professional studies) groups. Incident CKD was defined as new development of estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m 2 or urine albumin to creatinine ratio (ACR) ≥30 mg/g. Change in eGFR over 20 years was a secondary outcome., Results: At baseline, mean age was 35.0 ± 3.6 years, 47% were Black, and 55% were women. Participants with lower educational attainment were less likely to have high income and health insurance and to engage in a healthy lifestyle. Over 20 years, 407 participants developed CKD (13%). Compared with individuals with low educational attainment, those with medium and high educational attainment had an unadjusted hazard ratios for CKD of 0.79 (95% confidence interval [CI] 0.65-0.97) and 0.44 (95% CI, 0.30-0.63), respectively. This association was no longer significant after adjusting for income, health insurance, lifestyle, and health status. Low educational attainment was significantly associated with a change in eGFR in crude and adjusted analyses, although the association was attenuated in the multivariable models (low: -0.83 [95% CI, -0.91 to -0.75], medium: -0.80 (95% CI, -0.95 to -0.64), and high: -0.70 (95% CI, -0.89 to -0.52) ml/min per 1.73 m 2 per yr)., Conclusions: Health care access, lifestyle, and comorbid conditions likely help explain the association between low educational attainment and incident CKD in young adults., (© 2020 International Society of Nephrology. Published by Elsevier Inc.)

Rationale: Lower NP (natriuretic peptide) levels may contribute to the development of cardiometabolic diseases. Blacks have lower NP levels than middle-aged and older white adults. A high-carbohydrate challenge causes an upregulation of a negative ANP regulator microRNA-425 ( miR-425 ), which reduces ANP (atrial-NP) levels in whites., Objectives: We designed a prospective trial to study racial differences in (1) NP levels among young adults, (2) NP response to a high-carbohydrate challenge, and (3) explore underlying mechanisms for race-based differences., Methods and Results: Healthy self-identified blacks and whites received 3 days of study diet followed by a high-carbohydrate challenge. Gene expression from whole blood RNA was assessed in the trial participants. Additionally, atrial and ventricular tissue samples from the Myocardial Applied Genomics Network repository were examined for NP system gene expression. Among 72 healthy participants, we found that B-type-NP, NT-proBNP (N-terminal-pro-B-type NP), and MRproANP (midregional-pro-ANP) levels were 30%, 47%, and 18% lower in blacks compared with whites ( P ≤0.01), respectively. The decrease in MRproANP levels in response to a high-carbohydrate challenge differed by race (blacks 23% [95% CI, 19%-27%] versus whites 34% [95% CI, 31%-38]; P interaction <0.001), with no change in NT-proBNP levels. We did not observe any racial differences in expression of genes encoding for NPs ( NPPA/NPPB ) or NP signaling ( NPR1 ) in atrial and ventricular tissues. NP processing ( corin ), clearance ( NPR3 ), and regulation ( miR-425 ) genes were ≈3.5-, ≈2.5-, and ≈2-fold higher in blacks than whites in atrial tissues, respectively. We also found a 2-and 8-fold higher whole blood RNA expression of gene encoding for Neprilysin ( MME ) and miR-425 among blacks than whites., Conclusions: Racial differences in NP levels are evident in young, healthy adults suggesting a state of NP deficiency exists in blacks. Impaired NP processing and clearance may contribute to race-based NP differences. Higher miR-425 levels in blacks motivate additional studies to understand differences in NP downregulation after physiological perturbations., Clinical Trial Registration: URL: https://clinicaltrials.gov/ct2/show/NCT03072602. Unique identifier: NCT03072602.

Background: Antiretroviral therapy (ART) durability, time to modification or cessation, has declined. The study objective was to determine whether kidney dysfunction is contributing to reduced durability., Methods: This retrospective follow-up study of CNICS evaluated treatment-naive PLWH initiating ART between 2007 and 2014. Regimen modification was defined as cessation/modification of any part of the 3-drug ART regimen. We evaluated the role of kidney dysfunction in initial regimen modification as both a mediator and effect measure modifier. Associations of the variables with the ART modification were examined using univariable and multivariable Cox proportional hazard models., Results: Of 4515 PLWH included in the analysis, 1967 modified their ART. Of those receiving TDF-based ART (n = 3888), 1580 (41%) modified their regimen compared with 387 (62%) receiving other regimens. Overall, the median eGFR decreased by 5 mL/min/1.73 m (quartiles: first = -16, third = 0) from baseline to follow-up. Of the 128 patients with low baseline eGFR (<60 mL/min/1.73 m), the final eGFR remained low in 73% while it increased to above 60 mL/min/1.73 m in 27%. Of the 4387 with normal baseline eGFR, only 135 (3%) had a final eGFR <60 mL/min/1.73 m. Those with low eGFR at the baseline and/or final visits were more likely to modify ART than others (hazards ratio = 1.75, 95% confidence interval: 1.39 to 2.19, P < 0.001). Relative to other regimens, TDF-based ART was less likely to be modified when accounting for numerous clinical and demographic traits., Conclusions: For patients in our study initiated on ART, including TDF-based ART, in the last decade, kidney dysfunction is not a major factor leading to regimen modification.

Rationale & Objective: Chronic kidney disease (CKD) is complicated by abnormalities that reflect disruption in filtration, tubular, and endocrine functions of the kidney. Our aim was to explore the relationship of specific laboratory result abnormalities and hypertension with the estimated glomerular filtration rate (eGFR) and albuminuria CKD staging framework., Study Design: Cross-sectional individual participant-level analyses in a global consortium., Setting & Study Populations: 17 CKD and 38 general population and high-risk cohorts., Selection Criteria for Studies: Cohorts in the CKD Prognosis Consortium with data for eGFR and albuminuria, as well as a measurement of hemoglobin, bicarbonate, phosphorus, parathyroid hormone, potassium, or calcium, or hypertension., Data Extraction: Data were obtained and analyzed between July 2015 and January 2018., Analytical Approach: We modeled the association of eGFR and albuminuria with hemoglobin, bicarbonate, phosphorus, parathyroid hormone, potassium, and calcium values using linear regression and with hypertension and categorical definitions of each abnormality using logistic regression. Results were pooled using random-effects meta-analyses., Results: The CKD cohorts (n=254,666 participants) were 27% women and 10% black, with a mean age of 69 (SD, 12) years. The general population/high-risk cohorts (n=1,758,334) were 50% women and 2% black, with a mean age of 50 (16) years. There was a strong graded association between lower eGFR and all laboratory result abnormalities (ORs ranging from 3.27 [95% CI, 2.68-3.97] to 8.91 [95% CI, 7.22-10.99] comparing eGFRs of 15 to 29 with eGFRs of 45 to 59mL/min/1.73m 2 ), whereas albuminuria had equivocal or weak associations with abnormalities (ORs ranging from 0.77 [95% CI, 0.60-0.99] to 1.92 [95% CI, 1.65-2.24] comparing urinary albumin-creatinine ratio > 300 vs < 30mg/g)., Limitations: Variations in study era, health care delivery system, typical diet, and laboratory assays., Conclusions: Lower eGFR was strongly associated with higher odds of multiple laboratory result abnormalities. Knowledge of risk associations might help guide management in the heterogeneous group of patients with CKD., (Copyright © 2018 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Blacks have the highest prevalence of hypertension in the United States. Higher levels of FGF23 (fibroblast growth factor-23) have been associated with worse cardiovascular outcomes. Whether FGF23 is associated with rising blood pressure (BP) and racial differences in incident hypertension is unclear. We studied 1758 adults (45.0±3.7 years; 57.8% female; 36.9% black) without hypertension or cardiovascular disease who participated in the year 20 (2005-2006) follow-up examination of the CARDIA study (Coronary Artery Risk Development in Young Adults). We investigated the associations of baseline (year 20) cFGF23 (C-terminal FGF23) levels with longitudinal BP patterns and incident hypertension (defined as being on antihypertensive medication, systolic BP ≥130 or diastolic BP ≥80 mm Hg) during 2 follow-up visits (years 25 and 30). During follow-up, 35.2% of participants developed hypertension. In multivariable linear mixed models, there were greater increases in systolic BP from year 20 to 25 and year 25 to 30 in the highest FGF23 quartile relative to the lowest quartile (+2.1 mm Hg, P =0.0057 and +2.2 mm Hg, P =0.0108, respectively for each time period), whereas there were greater increases in diastolic BP from year 20 to 25 in the highest quartile relative to the lowest (+1.6 mm Hg; P =0.0024). In multivariable modified Poisson regression analyses, the highest FGF23 quartile was associated with a 45% greater risk of developing hypertension during follow-up compared with the lowest quartile (relative risk, 1.45 [1.18-1.77]). Results did not vary by race ( P interaction =0.1523). Higher FGF23 levels are independently associated with rising BP over time and an increased risk of incident hypertension but not racial differences in hypertension., (© 2018 American Heart Association, Inc.)

Background: Previous studies in HIV-infected individuals have demonstrated serum albumin to be strongly associated with kidney function decline, independent of urine albumin and inflammatory markers. Lower serum albumin concentrations may be an under-appreciated risk factor for kidney function decline in elders., Methods: We performed a cohort analysis in the Health Aging and Body Composition Study, a cohort of well-functioning, bi-racial, community-dwelling elders between the age of 70 and 79 years. We examined the associations of serum albumin concentration with longitudinal kidney function decline by estimated glomerular filtration rate (eGFR). Outcomes included linear eGFR decline, rapid kidney function decline defined as >30% decrease in eGFR, defined as a final eGFR <60 mL/min/1.73 m2 in those with an eGFR >60 mL/min/1.73 m2 at baseline. Cystatin C-based eGFR was calculated at baseline, Year 3 and Year 10., Results: Mean age was 74 years, and mean eGFR was 73 mL/min/1.73 m2 at baseline. The mean rate of eGFR change was 1.81 mL/min/1.73 m2 per year. After multivariate adjustment, lower serum albumin concentrations were strongly and independently associated with kidney function decline (-0.11 mL/min/1.73 m2 per year for each standard deviation decrease serum albumin; -0.01 to - 0.20) with no attenuation after adjustment for urine albumin and inflammatory markers (-0.12, -0.03 to - 0.22). When divided into quartiles, serum albumin levels ≤3.80 g/dL were associated with increased odds of rapid kidney function decline (odds ratio 1.59; 1.12-2.26) and increased risk of incident chronic kidney disease (incident rate ratio 1.29; 1.03-1.62) relative to levels >4.21g/dL. Urine albumin to creatinine ratio (ACR) was also significantly and independently associated with kidney function decline (-0.08 mL/min/1.73 m2 per year for urine ACR >30 mg/g; -0.82 to - 0.13)., Conclusions: Lower serum albumin levels are strongly and independently associated with kidney function decline in elders, independent of clinical risk factors, urine albumin and measured inflammatory markers.

Background: APOL1 genetic variants confer an increased risk for kidney disease. Their associations with cardiovascular disease (CVD) are less certain. We aimed to compare the prevalence of subclinical CVD and incidence of atherosclerotic CVD and heart failure by APOL1 genotypes among self-identified black participants of MESA (Multi-Ethnic Study of Atherosclerosis)., Methods and Results: Cross-sectional associations of APOL1 genotypes (high-risk=2 alleles; low-risk=0 or 1 allele) with coronary artery calcification, carotid-intimal media thickness, and left ventricular mass were evaluated using logistic and linear regression. Longitudinal associations of APOL1 genotypes with incident myocardial infarction, stroke, coronary heart disease, and congestive heart failure were examined using Cox regression. We adjusted for African ancestry, age, and sex. We also evaluated whether hypertension or kidney function markers explained the observed associations. Among 1746 participants with APOL1 genotyping (mean age 62 years, 55% women, mean cystatin C-based estimated glomerular filtration rate 89 mL/min per 1.73 m 2 , 12% with albuminuria), 12% had the high-risk genotypes. We found no difference in prevalence or severity of coronary artery calcification, carotid-intimal media thickness, or left ventricular mass by APOL1 genotypes. The APOL1 high-risk group was 82% more likely to develop incident heart failure compared with the low-risk group (95% confidence interval, 1.01-3.28). Adjusting for hypertension (hazard ratio, 1.80; 95% confidence interval, 1.00-3.24) but not markers of kidney function (hazard ratio, 1.86; 95% confidence interval, 1.03-3.35) slightly attenuated this association. The APOL1 high-risk genotypes were not significantly associated with other clinical CVD outcomes., Conclusions: Among blacks without baseline CVD, the APOL1 high-risk variants may be associated with increased risk for incident heart failure but not subclinical CVD or incident clinical atherosclerotic CVD., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Whether APOL1 polymorphisms contribute to the excess risk of hypertension among blacks is unknown. To assess this we evaluated whether self-reported race and, in blacks, APOL1 risk variants (high-risk [2 risk alleles] versus low-risk [0-1 risk allele]) were associated with longitudinal blood pressure. Blood pressure trajectories were determined using linear mixed-effects (slope) and latent class models (5 distinct groups) during 25 years of follow-up in the Coronary Artery Risk Development in Young Adults Study. Associations of race and APOL1 genotypes with blood pressure change, separately, using linear mixed-effects and multinomial logistic regression models, adjusting for demographic, socioeconomic, and traditional hypertension risk factors, anti-hypertensive medication use, and kidney function were evaluated. Among 1700 whites and 1330 blacks (13% APOL1 high-risk, mean age 25 years; 46% male) mean mid-, ([systolic + diastolic blood pressure]/2), systolic, and diastolic blood pressures were 89, 110, and 69 mm Hg, respectively. One percent of participants used anti-hypertensive medications at baseline. Compared to whites, blacks, regardless of APOL1 genotype, had significantly greater increases in mid-blood pressure and were more likely to experience significantly increasing mid-blood pressure trajectories with adjusted relative risk ratios of 5.21 and 7.27 for moderate-increasing and elevated-increasing versus low-stable blood pressure, respectively. Among blacks, longitudinal mid-blood pressure changes and mid-blood pressure trajectory classification were similar by APOL1 risk status. Modeling systolic and diastolic blood pressure as outcomes yielded similar findings. From young adulthood to mid-life, blacks have greater blood pressure increases versus whites that are not fully explained by traditional risk factors. Thus APOL1 variants are not associated with longitudinal blood pressure in blacks., (Copyright © 2017 International Society of Nephrology. All rights reserved.)

The burden of premature death and health loss from ESRD is well described. Less is known regarding the burden of cardiovascular disease attributable to reduced GFR. We estimated the prevalence of reduced GFR categories 3, 4, and 5 (not on RRT) for 188 countries at six time points from 1990 to 2013. Relative risks of cardiovascular outcomes by three categories of reduced GFR were calculated by pooled random effects meta-analysis. Results are presented as deaths for outcomes of cardiovascular disease and ESRD and as disability-adjusted life years for outcomes of cardiovascular disease, GFR categories 3, 4, and 5, and ESRD. In 2013, reduced GFR was associated with 4% of deaths worldwide, or 2.2 million deaths (95% uncertainty interval [95% UI], 2.0 to 2.4 million). More than half of these attributable deaths were cardiovascular deaths (1.2 million; 95% UI, 1.1 to 1.4 million), whereas 0.96 million (95% UI, 0.81 to 1.0 million) were ESRD-related deaths. Compared with metabolic risk factors, reduced GFR ranked below high systolic BP, high body mass index, and high fasting plasma glucose, and similarly with high total cholesterol as a risk factor for disability-adjusted life years in both developed and developing world regions. In conclusion, by 2013, cardiovascular deaths attributed to reduced GFR outnumbered ESRD deaths throughout the world. Studies are needed to evaluate the benefit of early detection of CKD and treatment to decrease these deaths., (Copyright © 2017 by the American Society of Nephrology.)

Vitamin D and intact parathyroid hormone (iPTH) concentrations differ between individuals of African and European descent and may play a role in observed racial differences in bone mineral density (BMD). These findings suggest that mapping by admixture linkage disequilibrium (MALD) may be informative for identifying genetic variants contributing to these ethnic disparities. Admixture mapping was performed for serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, vitamin D-binding protein (VDBP), bioavailable vitamin D, and iPTH concentrations and computed tomography measured thoracic and lumbar vertebral volumetric BMD in 552 unrelated African Americans with type 2 diabetes from the African American-Diabetes Heart Study. Genotyping was performed using a custom Illumina ancestry informative marker (AIM) panel. For each AIM, the probability of inheriting 0, 1, or 2 copies of a European-derived allele was determined. Non-parametric linkage analysis was performed by testing for association between each AIM using these probabilities among phenotypes, accounting for global ancestry, age, and gender. Fine-mapping of MALD peaks was facilitated by genome-wide association study (GWAS) data. VDBP levels were significantly linked in proximity to the protein coding locus (rs7689609, LOD=11.05). Two loci exhibited significant linkage signals for 1,25-dihydroxyvitamin D on 13q21.2 (rs1622710, LOD=3.20) and 12q13.2 (rs11171526, LOD=3.10). iPTH was significantly linked on 9q31.3 (rs7854368, LOD=3.14). Fine-mapping with GWAS data revealed significant known (rs7041 with VDBP, P=1.38×10(-82)) and novel (rs12741813 and rs10863774 with VDBP, P<6.43×10(-5)) loci with plausible biological roles. Admixture mapping in combination with fine-mapping has focused efforts to identify loci contributing to ethnic differences in vitamin D-related traits., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Lipid-lowering guidelines endorse a low-density lipoprotein cholesterol goal of <100 mg/dL for people with coronary heart disease (CHD). A more stringent threshold of <70 mg/dL is recommended for those with CHD and "very high-risk" conditions such as diabetes mellitus, metabolic syndrome, or cigarette smoking. Whether chronic kidney disease (CKD) confers a similar risk for recurrent CHD events is unknown., Methods and Results: We evaluated the risk for recurrent CHD events and all-cause mortality among 3,938 participants ≥45 years with CHD in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. Chronic kidney disease was defined by estimated glomerular filtration rate <60 mL/min per 1.73 m(2) or urinary albumin to creatinine ratio ≥30 mg/g. Participants were categorized by the presence or absence of CKD and any very high-risk condition. Over a median of 4.1 years, the crude incidence (95% CI) of recurrent CHD events were 12.1 (9.0-15.2), 18.9 (15.5-22.3), 35.0 (25.4-44.6), and 34.2 (28.2-40.3) among those without CKD or high-risk conditions; very high-risk conditions alone; and CKD alone and both CKD and very high-risk conditions. After multivariable adjustment, compared with those without CKD or very high-risk conditions, the hazard ratio (95% CI) for recurrent CHD events was 1.45 (1.02-2.05), 2.24 (1.50-3.34), and 2.10 (1.47-2.98) among those with very high-risk conditions alone, CKD alone, and both CKD and very high-risk conditions, respectively. Results were consistent for all-cause mortality., Conclusions: Chronic kidney disease is associated with risk for recurrent CHD events that approximates or is larger than other established very high-risk conditions., (Copyright © 2013 Mosby, Inc. All rights reserved.)