Differences in Risk of Sudden Cardiac Death Between Blacks and Whites.

BACKGROUND: Prior studies have consistently demonstrated that blacks have an approximate 2-fold higher incidence of sudden cardiac death (SCD) than whites; however, these analyses have lacked individual-level sociodemographic, medical comorbidity, and behavioral health data. OBJECTIVES: The purpose of this study was to evaluate whether racial differences in SCD incidence are attributable to differences in the prevalence of risk factors or rather to underlying susceptibility to fatal arrhythmias. METHODS: The Reasons for Geographic and Racial Differences in Stroke study is a prospective, population-based cohort of adults from across the United States. Associations between race and SCD defined per National Heart, Lung, and Blood Institute criteria were assessed. RESULTS: Among 22,507 participants (9,416 blacks and 13,091 whites) without a history of clinical cardiovascular disease, there were 174 SCD events (67 whites and 107 blacks) over a median follow-up of 6.1 years (interquartile range: 4.6 to 7.3 years). The age-adjusted SCD incidence rate (per 1,000 person-years) was higher in blacks (1.8; 95% confidence interval [CI]: 1.4 to 2.2) compared with whites (0.7; 95% CI: 0.6 to 0.9), with an unadjusted hazard ratio of 2.35; 95% CI: 1.74 to 3.20. The association of black race with SCD risk remained significant after adjustment for sociodemographics, comorbidities, behavioral measures of health, intervening cardiovascular events, and competing risks of non-SCD mortality (hazard ratio: 1.97; 95% CI: 1.39 to 2.77). CONCLUSIONS: In a large biracial population of adults without a history of cardiovascular disease, SCD rates were significantly higher in blacks as compared with whites. These racial differences were not fully explained by demographics, adverse socioeconomic measures, cardiovascular risk factors, and behavioral measures of health.

Dietary Oxidative Balance Scores and Biomarkers of Inflammation among Individuals with and without Chronic Kidney Disease.

BACKGROUND: Oxidative stress and inflammation are proposed mechanisms of nonspecific kidney injury and progressive kidney failure. Higher dietary oxidative balance scores (OBS) are associated with lower prevalence of chronic kidney disease (CKD). METHODS: We investigated the association between OBS and biomarkers of inflammation using data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. Nutrient estimates from the Block Food Frequency Questionnaires were used to define tertiles of 11 pro- and antioxidant factors. Points for each OBS component were summed, with a higher score indicating predominance of antioxidant exposures. Multivariable linear regression models were used to estimate the association between OBS and biomarkers of inflammation (interleukin-6 [IL-6], interleukin-8 [IL-8], interleukin-10 [IL-10], fibrinogen, C-reactive protein [CRP], white blood cell count, and cystatin C). An interaction term was included to determine if associations between OBS and inflammatory markers differed between individuals with and without CKD. RESULTS: Of 682 participants, 22.4% had CKD. In adjusted models, OBS was associated with CRP and IL-6. For every 5-unit increase in OBS, the CRP concentration was -15.3% lower (95% CI: -25.6, -3.6). The association of OBS with IL-6 differed by CKD status; for every 5-unit increase in OBS, IL-6 was -10.7% lower (95% CI: -16.3, -4.7) among those without CKD, but there was no association among those with CKD (p = 0.03). CONCLUSION: This study suggests that a higher OBS is associated with more favorable levels of IL-6 and CRP, and that the association of OBS and IL-6 may be modified by CKD status.

Pre-ESRD Care and Mortality in Incident ESRD Patients With Multiple Myeloma.

OBJECTIVES: The relationship between mortality and pre-ESRD (end-stage renal disease) nephrology care in incident ESRD patients with multiple myeloma (MM) as the primary cause of renal failure has not been examined. MATERIALS AND METHODS: Among 439,206 incident US hemodialysis patients with MM as the primary cause of ESRD (June 1, 2005 to May 31, 2009) identified using the US Renal Data System, adjusted odds ratios (OR) for reported pre-ESRD nephrology care for ESRD due to MM (n=4561) versus other causes (n=434,645) were calculated. The association of pre-ESRD nephrology care with subsequent mortality in MM-ESRD patients was examined. RESULTS: MM-ESRD patients were less likely to have any predialysis nephrology care in the year before initiation of dialysis (34.8% vs. 58.5%; OR=0.38; 95% confidence interval [CI], 0.34-0.43) compared with patients with ESRD due to other causes. MM-ESRD patients compared with others were more likely to have catheters on first dialysis (91.8% vs. 75.6%; OR=4.15; 95% CI, 3.54-4.86). Incident MM-ESRD patients receiving predialysis care for ≥6 months had significantly lower 1-year mortality (hazard ratio 0.89; 95% CI, 0.82-0.97 and 0.88; 95% CI, 0.80-0.96, respectively), relative to those without this care. A catheter for dialysis access was associated with a 1.6-fold increase in 1-year mortality in incident MM-ESRD (hazard ratio 1.55; 95% CI, 1.32-1.83). CONCLUSIONS: MM-ESRD patients were less likely to have predialysis nephrology care and more likely to use catheters on first dialysis. However, predialysis care is independently associated with lower mortality in MM-ESRD patients. Predialysis care should be prioritized in MM patients approaching ESRD.

Older Patients' Perspectives on Managing Complexity in CKD Self-Management.

BACKGROUND AND OBJECTIVES: Patients with CKD are asked to perform self-management tasks including dietary changes, adhering to medications, avoiding nephrotoxic drugs, and self-monitoring hypertension and diabetes. Given the effect of aging on functional capacity, self-management may be especially challenging for older patients. However, little is known about the specific challenges older adults face maintaining CKD self-management regimens. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted an exploratory qualitative study designed to understand the relationship among factors facilitating or impeding CKD self-management in older adults. Six focus groups (n=30) were held in August and September of 2014 with veterans≥70 years old with moderate-to-severe CKD receiving nephrology care at the Atlanta Veterans Affairs Medical Center. Grounded theory with a constant comparative method was used to collect, code, and analyze data. RESULTS: Participants had a mean age (range) of 75.1 (70.1-90.7) years, 60% were black, and 96.7% were men. The central organizing concept that emerged from these data were managing complexity. Participants typically did not have just one chronic condition, CKD, but a number of commonly co-occurring conditions. Recommendations for CKD self-management therefore occurred within a complex regimen of recommendations for managing other diseases. Participants identified overtly discordant treatment recommendations across chronic conditions (e.g., arthritis and CKD). Prioritization emerged as one effective strategy for managing complexity (e.g., focusing on BP control). Some patients arrived at the conclusion that they could group concordant recommendations to simplify their regimens (e.g., protein restriction for both gout and CKD). CONCLUSIONS: Among older veterans with moderate-to-severe CKD, multimorbidity presents a major challenge for CKD self-management. Because virtually all older adults with CKD have multimorbidity, an integrated treatment approach that supports self-management across commonly occurring conditions may be necessary to meet the needs of these patients.

ESRD Databases, Public Policy, and Quality of Care: Translational Medicine and Nephrology.

Efforts to improve care of patients with ESRD and the policies that guide those activities depend on evidence-based best practices derived from clinical trials and carefully conducted observational studies. Our review describes this process in the context of the translational research model (bench to bedside to populations), with a particular emphasis on bedside care. We illustrate some of its accomplishments and describe the limitations of the data and evidence supporting policy and practice.

Albuminuria, kidney function, and sudden cardiac death: Findings from The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study.

BACKGROUND: Moderate-to-severe kidney disease increases risk for sudden cardiac death (SCD). Limited studies have evaluated how mild degrees of kidney dysfunction impact SCD risk. OBJECTIVE: The purpose of this study was to evaluate the association of albuminuria, which is one of the earliest biomarkers of kidney injury, and SCD. METHODS: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study is a prospective, population-based cohort of U.S. adults. Associations between albuminuria, which is categorized using urinary albumin-to-creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and SCD were assessed independently and in combination. RESULTS: After median follow-up of 6.1 years, we identified 335 SCD events. Compared to participants with ACR <15 mg/g, those with higher levels had an elevated adjusted risk of SCD (ACR 15-30 mg/g, hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.11-2.11; ACR >30 mg/g, HR 1.56, 95% CI 1.17-2.11). In contrast, compared to the group with eGFR >90 mL/min/1.73 m2, the adjusted risk of SCD was significantly elevated only among those with eGFR <45 mL/min/1.73 m2 (HR 1.66, 95% CI 1.06-2.58). The subgroup with eGFR <45 mL/min/1.73 m2 (n = 1003) comprised 3.7% of REGARDS, whereas ACR 15-30 mg/g (n = 3089 [11.3%]) and ACR >30 mg/g (n = 4040 [14.8%] were far more common. In the analysis that combined ACR and eGFR categories, albuminuria consistently identified individuals with eGFR ≥60 mLmin/1.73 m2 who were at significantly increased SCD risk. CONCLUSION: Low levels of kidney injury as measured by ACR predict an increase in SCD risk.

A Randomized Trial to Reduce Disparities in Referral for Transplant Evaluation.

Georgia has the lowest kidney transplant rates in the United States and substantial racial disparities in transplantation. We determined the effectiveness of a multicomponent intervention to increase referral of patients on dialysis for transplant evaluation in the Reducing Disparities in Access to kidNey Transplantation Community Study (RaDIANT), a randomized, dialysis facility-based, controlled trial involving >9000 patients receiving dialysis from 134 dialysis facilities in Georgia. In December of 2013, we selected dialysis facilities with either low transplant referral or racial disparity in referral. The intervention consisted of transplant education and engagement activities targeting dialysis facility leadership, staff, and patients conducted from January to December of 2014. We examined the proportion of patients with prevalent ESRD in each facility referred for transplant within 1 year as the primary outcome, and disparity in the referral of black and white patients as a secondary outcome. Compared with control facilities, intervention facilities referred a higher proportion of patients for transplant at 12 months (adjusted mean difference [aMD], 7.3%; 95% confidence interval [95% CI], 5.5% to 9.2%; odds ratio, 1.75; 95% CI, 1.36 to 2.26). The difference between intervention and control facilities in the proportion of patients referred for transplant was higher among black patients (aMD, 6.4%; 95% CI, 4.3% to 8.6%) than white patients (aMD, 3.7%; 95% CI, 1.6% to 5.9%; P<0.05). In conclusion, this intervention increased referral and improved equity in kidney transplant referral for patients on dialysis in Georgia; long-term follow-up is needed to determine whether these effects led to more transplants.

Interdialytic Weight Gain: Trends, Predictors, and Associated Outcomes in the International Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: High interdialytic weight gain (IDWG) is associated with adverse outcomes in hemodialysis (HD) patients. We identified temporal and regional trends in IDWG, predictors of IDWG, and associations of IDWG with clinical outcomes. STUDY DESIGN: Analysis 1: sequential cross-sections to identify facility- and patient-level predictors of IDWG and their temporal trends. Analysis 2: prospective cohort study to assess associations between IDWG and mortality and hospitalization risk. SETTING & PARTICIPANTS: 21,919 participants on HD therapy for 1 year or longer in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 2 to 5 (2002-2014). PREDICTORS: Analysis 1: study phase, patient demographics and comorbid conditions, HD facility practices. Analysis 2: relative IDWG, expressed as percentage of post-HD weight (<0%, 0%-0.99%, 1%-2.49%, 2.5%-3.99% [reference], 4%-5.69%, and ≥5.7%). OUTCOMES: Analysis 1: relative IDWG as a continuous variable using linear mixed models; analysis 2: mortality; all-cause and cause-specific hospitalization using Cox regression, adjusting for potential confounders. RESULTS: From phase 2 to 5, IDWG declined in the United States (-0.29kg; -0.5% of post-HD weight), Canada (-0.25kg; -0.8%), and Europe (-0.22kg; -0.5%), with more modest declines in Japan and Australia/New Zealand. Among modifiable factors associated with IDWG, the most notable was facility mean dialysate sodium concentration: every 1-mEq/L greater dialysate sodium concentration was associated with 0.13 (95% CI, 0.11-0.16) greater relative IDWG. Compared to relative IDWG of 2.5% to 3.99%, there was elevated risk for mortality with relative IDWG≥5.7% (adjusted HR, 1.23; 95% CI, 1.08-1.40) and elevated risk for fluid-overload hospitalization with relative IDWG≥4% (HRs of 1.28 [95% CI, 1.09-1.49] and 1.64 [95% CI, 1.27-2.13] for relative IDWGs of 4%-5.69% and ≥5.7%, respectively). LIMITATIONS: Possible residual confounding. No dietary salt intake data. CONCLUSIONS: Reductions in IDWG during the past decade were partially explained by reductions in dialysate sodium concentration. Focusing quality improvement strategies on reducing occurrences of high IDWG may improve outcomes in HD patients.

Dietary flavonoid intake and incident coronary heart disease: the REasons for Geographic and Racial Differences in Stroke (REGARDS) study.

BACKGROUND: Flavonoids are dietary polyphenolic compounds with a variety of proposed beneficial cardiovascular effects, but rigorous prospective studies that examine the association between flavonoid intake and incident coronary heart disease (CHD) in geographically and racially diverse US samples are limited. OBJECTIVE: With the use of the new, expanded USDA flavonoid database, we assessed the association between total flavonoid and flavonoid subclass intakes with incident CHD in a biracial and geographically diverse cohort, as well as effect modification by age, sex, race, and region of residence. DESIGN: Participants were 16,678 black and white men and women enrolled in the REGARDS (REasons for Geographic and Racial Differences in Stroke) study, a national prospective cohort study. All participants were without CHD at baseline, and all completed a Block98 food-frequency questionnaire. Flavonoid intakes were estimated from USDA flavonoid databases, which were recently improved to address missing values for cooked foods and to adjust for flavonoid losses due to processing. Incident CHD events were participant reported and adjudicated by experts. Quintiles of flavonoid intake were examined as predictors of incident CHD by using Cox proportional hazards regression to obtain HRs. Tests for trend used the quintile medians. RESULTS: Over a mean ± SD follow-up of 6.0 ± 1.9 y, 589 CHD events occurred. High flavonoid intake was associated with self-identified white race, exercise, not smoking, more education, and higher income. In models that adjusted for sociodemographic, health behavior, and dietary factors, there was an inverse association between anthocyanidin and proanthocyanidin intakes and incident CHD (HRs for quintile 5 compared with quintile 1-anthocyanidins: 0.71; 95% CI: 0.52, 0.98; P-trend = 0.04; proanthocyanidins: 0.63; 95% CI: 0.47, 0.84; P-trend = 0.02). There was no association between total flavonoid or other flavonoid subclass intakes and incident CHD. CONCLUSIONS: Reported anthocyanidin and proanthocyanidin intakes were inversely associated with incident CHD. There was no significant effect modification by age, sex, race, or region of residence.

Hemoglobin Concentration and Risk of Incident Stroke in Community-Living Adults.

BACKGROUND AND PURPOSE: In previous observational studies, hemoglobin concentrations have been associated with an increased risk of stroke. However, these studies were limited by a relatively low number of stroke events, making it difficult to determine whether the association of hemoglobin and stroke differed by demographic or clinical factors. METHODS: Using Cox proportional hazards analysis and Kaplan-Meier plots, we examined the association of baseline hemoglobin concentrations with incident stroke in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a cohort of black and white adults aged ≥45 years. RESULTS: A total of 518 participants developed stroke over a mean 7±2 years of follow-up. There was a statistically significant interaction between hemoglobin and sex (P=0.05) on the risk of incident stroke. In Cox regression models adjusted for demographic and clinical variables, there was no association of baseline hemoglobin concentration with incident stroke in men, whereas in women, the lowest (<12.4 g/dL) and highest (>14.0 g/dL) quartiles of hemoglobin were associated with higher risk of stroke when compared with the second quartile (12.4-13.2 g/dL; quartile 1: hazard ratio, 1.59; 95% confidence interval, 1.09-2.31; quartile 2: referent; quartile 3: hazard ratio, 0.91; 95% confidence interval, 0.59-1.38; quartile 4: hazard ratio, 1.59; 95% confidence interval, 1.08-2.35). Similar results were observed in models stratified by hemoglobin and sex and when hemoglobin was modeled as a continuous variable using restricted quadratic spline regression. CONCLUSIONS: Lower and higher hemoglobin concentrations were associated with a higher risk of incident stroke in women. No such associations were found in men.

iChoose Kidney: A Clinical Decision Aid for Kidney Transplantation Versus Dialysis Treatment.

BACKGROUND: Despite a significant survival advantage of kidney transplantation compared with dialysis, nearly one third of end-stage renal disease (ESRD) patients are not educated about kidney transplantation as a treatment option at the time of ESRD diagnosis. Access to individualized, evidence-based prognostic information is needed to facilitate and encourage shared decision making about the clinical implications of whether to pursue transplantation or long-term dialysis. METHODS: We used a national cohort of incident ESRD patients in the US Renal Data System surveillance registry from 2005 to 2011 to develop and validate prediction models for risk of 1- and 3-year mortality among dialysis versus kidney transplantation. Using these data, we developed a mobile clinical decision aid that provides estimates of risks of death and survival on dialysis compared with kidney transplantation patients. RESULTS: Factors included in the mortality risk prediction models for dialysis and transplantation included age, race/ethnicity, dialysis vintage, and comorbidities, including diabetes, hypertension, cardiovascular disease, and low albumin. Among the validation cohorts, the discriminatory ability of the model for 3-year mortality was moderate (c statistic, 0.7047; 95% confidence interval, 0.7029-0.7065 for dialysis and 0.7015; 95% confidence interval, 0.6875-0.7155 for transplant). We used these risk prediction models to develop an electronic, user-friendly, mobile (iPad, iPhone, and website) clinical decision aid called iChoose Kidney. CONCLUSIONS: The use of a mobile clinical decision aid comparing individualized mortality risk estimates for dialysis versus transplantation could enhance communication between ESRD patients and their clinicians when making decisions about treatment options.

Friends, social networks, and progressive chronic kidney disease.

A report by Dunkler et al. reminds us that social factors are relevant for today's clinical scientist and practitioner. They report that an increasing number of friends reduces the incidence and progression of chronic kidney disease in type 2 diabetes. The observation that 'friends don't let friends' develop kidney disease suggests that social factors, as well as biomarkers, may be relevant in developing 'personalized renal medicine' and may identify areas for future nephrology research and education.

Underreporting of nursing home utilization on the CMS-2728 in older incident dialysis patients and implications for assessing mortality risk.

BACKGROUND: The usage of nursing home (NH) services is a marker of frailty among older adults. Although the Centers for Medicare & Medicaid Services (CMS) revised the Medical Evidence Report Form CMS-2728 in 2005 to include data collection on NH institutionalization, the validity of this item has not been reported. METHODS: There were 27,913 patients ≥ 75 years of age with incident end-stage renal disease (ESRD) in 2006, which constituted our analysis cohort. We determined the accuracy of the CMS-2728 using a matched cohort that included the CMS Minimum Data Set (MDS) 2.0, often employed as a "gold standard" metric for identifying patients receiving NH care. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the CMS-2728 NH item. Next, we compared characteristics and mortality risk by CMS-2728 and MDS NH status agreement. RESULTS: The sensitivity, specificity, PPV and NPV of the CMS-2728 for NH status were 33%, 97%, 80% and 79%, respectively. Compared to those without the MDS or CMS-2728 NH indicator (No MDS/No 2728), multivariable adjusted hazard ratios (95% confidence interval) for mortality associated with NH status were 1.55 (1.46 - 1.64) for MDS/2728, 1.48 (1.42 - 1.54) for MDS/No 2728, and 1.38 (1.25 - 1.52) for No MDS/2728. NH utilization was more strongly associated with mortality than other CMS-2728 items in the model. CONCLUSIONS: The CMS-2728 underestimated NH utilization among older adults with incident ESRD. The potential for misclassification may have important ramifications for assessing prognosis, developing advanced care plans and providing coordinated care.

Sociodemographic and geographic predictors of quality of care in United States patients with end-stage renal disease due to lupus nephritis.

OBJECTIVE: To describe end-stage renal disease (ESRD) quality of care (receipt of pre-ESRD nephrology care, access to kidney transplantation, and placement of permanent vascular access for dialysis) in US patients with ESRD due to lupus nephritis (LN-ESRD) and to examine whether quality measures differ by patient sociodemographic characteristics or US region. METHODS: National surveillance data on patients in the US in whom treatment for LN-ESRD was initiated between July 2005 and September 2011 (n = 6,594) were analyzed. Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were determined for each quality measure, according to sociodemographic factors and US region. RESULTS: Overall, 71% of the patients received nephrology care prior to ESRD. Black and Hispanic patients were less likely than white patients to receive pre-ESRD care (OR 0.73 [95% CI 0.63-0.85] and OR 0.73 [95% CI 0.60-0.88], respectively) and to be placed on the kidney transplant waitlist within the first year after the start of ESRD (HR 0.78 [95% CI 0.68-0.91] and HR 0.82 [95% CI 0.68-0.98], respectively). Those with Medicaid (HR 0.51 [95% CI 0.44-0.58]) or no insurance (HR 0.36 [95% CI 0.29-0.44]) were less likely than those with private insurance to be placed on the waitlist. Only 24% had a permanent vascular access, and placement was even less likely among the uninsured (OR 0.62 [95% CI 0.49-0.79]). ESRD quality-of-care measures varied 2-3-fold across regions of the US, with patients in the Northeast and Northwest generally having higher probabilities of adequate care. CONCLUSION: LN-ESRD patients have suboptimal ESRD care, particularly with regard to placement of dialysis vascular access. Minority race/ethnicity and lack of private insurance are associated with inadequate ESRD care. Further studies are warranted to examine multilevel barriers to, and develop targeted interventions to improve delivery of, care among patients with LN-ESRD.

Racial and ethnic disparities in pediatric renal allograft survival in the United States.

This study was undertaken to describe the association of patient race/ethnicity and renal allograft survival among the national cohort of pediatric renal allograft recipients. Additionally, we determined whether racial and ethnic differences in graft survival exist among individuals living in low- or high-poverty neighborhoods and those with private or public insurance. Among 6216 incident, pediatric end-stage renal disease patients in the United States Renal Data System (kidney transplant from 2000 through September, 2011), 14.4% experienced graft failure, with a median follow-up time of 4.5 years. After controlling for multiple covariates, black race, but not Hispanic ethnicity, was significantly associated with a higher rate of graft failure for both deceased and living donor transplant recipients. Disparities were particularly stark by 5 years post transplant, when black living donor transplant recipients experienced only 63.0% graft survival compared with 82.8 and 80.8% for Hispanics and whites, respectively. These disparities persisted among high- and low-poverty neighborhoods and among both privately and publicly insured patients. Notably profound declines in both deceased and living donor graft survival rates for black, compared with white and Hispanic, children preceded the 3-year mark when transplant Medicare eligibility ends. Further research is needed to identify the unique barriers to long-term graft success among black pediatric transplant recipients.

Association of time to kidney transplantation with graft failure among U.S. patients with end-stage renal disease due to lupus nephritis.

OBJECTIVE: Providers recommend waiting to transplant patients with end-stage renal disease (ESRD) secondary to lupus nephritis (LN), to allow for quiescence of systemic lupus erythematosus (SLE)-related immune activity. However, these recommendations are not standardized, and we sought to examine whether duration of time to transplant was associated with risk of graft failure in US LN-ESRD patients. METHODS: Using national ESRD surveillance data (United States Renal Data System), we identified 4,743 US patients with LN-ESRD who received a first transplant on or after January 1, 2000 (followup through September 30, 2011). The association of wait time (time from ESRD start to transplant) with graft failure was assessed with Cox proportional hazards models, with splines of the exposure to allow for nonlinearity of the association and with adjustment for potential confounding by demographic, clinical, and transplant factors. RESULTS: White LN-ESRD patients who were transplanted later (versus at <3 months receiving dialysis) were at increased risk of graft failure (3-12 months: adjusted hazard ratio [HR] 1.23, 95% confidence interval [95% CI] 0.93-1.63; 12-24 months: adjusted HR 1.37, 95% CI 0.92-2.06; 24-36 months: adjusted HR 1.34, 95% CI 0.92-1.97; and >36 months: adjusted HR 1.98, 95% CI 1.31-2.99). However, no such association was seen among African American recipients (3-12 months: adjusted HR 1.07, 95% CI 0.79-1.45; 12-24 months: adjusted HR 1.01, 95% CI 0.64-1.60; 24-36 months: adjusted HR 0.78, 95% CI 0.51-1.18; and >36 months: adjusted HR 0.74, 95% CI 0.48-1.13). CONCLUSION: While future studies are needed to examine the potential confounding effect of clinically recognized SLE activity on the observed associations, these results suggest that longer wait times to transplant may be associated with equivalent or worse, not better, graft outcomes among LN-ESRD patients.

Obesity, metabolic health, and the risk of end-stage renal disease.

Obesity is associated with chronic kidney disease progression. Whether metabolic risk factors modify this association is unclear. Here we examined associations of body mass index (BMI) and metabolic health with risk of end-stage renal disease (ESRD) in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. Among 21,840 participants eligible for analysis, 247 developed ESRD (mean follow-up of 6.3 years). Metabolic health significantly modified the association of BMI with ESRD. In models stratified by the presence or absence of the metabolic syndrome and adjusted for demographic, lifestyle, and clinical factors, higher BMI was associated with lower risk of ESRD in those without (hazard ratio per 5 kg/m2 increase in BMI 0.70, 95% CI 0.52, 0.95) but not those with (hazard ratio, 1.06) the metabolic syndrome. In models stratified by weight and metabolic health, compared with normal weight (BMI 18.5-24.9 kg/m2) participants without the metabolic syndrome the overweight individuals (BMI 25-29.9) and obese individuals (BMI of 30 or more) with the metabolic syndrome had greater risk of ESRD (hazard ratios of 2.03 and 2.29, respectively), whereas obesity without the metabolic syndrome was associated with lower risk of ESRD (hazard ratio 0.47). Thus, higher BMI is associated with lower ESRD risk in those without but not those with the metabolic syndrome.

Low income, community poverty and risk of end stage renal disease.

BACKGROUND: The risk of end stage renal disease (ESRD) is increased among individuals with low income and in low income communities. However, few studies have examined the relation of both individual and community socioeconomic status (SES) with incident ESRD. METHODS: Among 23,314 U.S. adults in the population-based Reasons for Geographic and Racial Differences in Stroke study, we assessed participant differences across geospatially-linked categories of county poverty [outlier poverty, extremely high poverty, very high poverty, high poverty, neither (reference), high affluence and outlier affluence]. Multivariable Cox proportional hazards models were used to examine associations of annual household income and geospatially-linked county poverty measures with incident ESRD, while accounting for death as a competing event using the Fine and Gray method. RESULTS: There were 158 ESRD cases during follow-up. Incident ESRD rates were 178.8 per 100,000 person-years (105 py) in high poverty outlier counties and were 76.3 /105 py in affluent outlier counties, p trend=0.06. In unadjusted competing risk models, persons residing in high poverty outlier counties had higher incidence of ESRD (which was not statistically significant) when compared to those persons residing in counties with neither high poverty nor affluence [hazard ratio (HR) 1.54, 95% Confidence Interval (CI) 0.75-3.20]. This association was markedly attenuated following adjustment for socio-demographic factors (age, sex, race, education, and income); HR 0.96, 95% CI 0.46-2.00. However, in the same adjusted model, income was independently associated with risk of ESRD [HR 3.75, 95% CI 1.62-8.64, comparing the <$20,000 income group to the >$75,000 group]. There were no statistically significant associations of county measures of poverty with incident ESRD, and no evidence of effect modification. CONCLUSIONS: In contrast to annual family income, geospatially-linked measures of county poverty have little relation with risk of ESRD. Efforts to mitigate socioeconomic disparities in kidney disease may be best appropriated at the individual level.

Nondisease-specific problems and all-cause mortality among older adults with CKD: the REGARDS Study.

BACKGROUND AND OBJECTIVES: The term "nondisease-specific" has been used to describe problems that cross multiple domains of health and are not necessarily the result of a single underlying disease. Although individuals with reduced eGFR and elevated albumin-to-creatinine ratio have many comorbidities, the prevalence of and outcomes associated with nondisease-specific problems have not been well studied. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Participants included 3557 black and white United States adults ≥75 years of age from the Reasons for Geographic and Racial Differences in Stroke Study. Nondisease-specific problems included cognitive impairment, depressive symptoms, exhaustion, falls, impaired mobility, and polypharmacy. Hazard ratios for mortality over a median (interquartile range) of 5.4 (4.2-6.9) years of follow-up associated with one, two, or three to six nondisease-specific problems were calculated and stratified by eGFR (≥60, 45-59, and <45 ml/min per 1.73 m(2)) and separately, albumin-to-creatinine ratio (<30, 30-299, and ≥300 mg/g). Secondary outcomes included hospitalizations and emergency department visits over 1.8 (0.7-4.0) and 2.3 (0.9-4.7) years of follow-up, respectively. RESULTS: The prevalence of nondisease-specific problems was more common at lower eGFR and higher albumin-to-creatinine ratio levels. Within each eGFR and albumin-to-creatinine ratio strata, the risk for mortality was higher among those with a greater number of nondisease-specific problems. For example, among those with an eGFR=45-59 ml/min per 1.73 m(2), the multivariable adjusted hazard ratios (95% confidence intervals) for mortality associated with one, two, or three to six nondisease-specific problems were 1.17 (0.78 to 1.76), 1.95 (1.24 to 3.07), and 2.44 (1.39 to 4.27; P trend <0.001). Risk for hospitalization and emergency department visits was higher among those with more nondisease-specific problems within eGFR and albumin-to-creatinine ratio strata. CONCLUSIONS: Among older adults, nondisease-specific problems commonly co-occur with reduced eGFR and elevated albumin-to-creatinine ratio. Identification of nondisease-specific problems may provide mortality risk information independent of measures of kidney function.