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

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

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.

Sickle Cell Trait and the Risk of ESRD in Blacks.

Blacks, compared with whites, have an increased risk of progression to end-stage renal disease (ESRD). Emerging evidence suggests that, in addition to APOL1 high-risk genotypes, hemoglobin variants, including sickle cell trait (SCT) and hemoglobin C trait, have a role in kidney disease in blacks. However, the association between these hemoglobin traits and ESRD remains unknown. In a large population-based cohort, the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, we evaluated 9909 self-reported blacks (739 with SCT and 243 with hemoglobin C trait). Incident ESRD occurred in 40 of 739 (5.4%) individuals with SCT, six of 243 (2.5%) individuals with hemoglobin C trait, and 234 of 8927 (2.6%) noncarriers. The incidence rate for ESRD was 8.5 per 1000 person-years for participants with SCT and 4.0 per 1000 person-years for noncarriers. Compared with individuals without SCT, individuals with SCT had a hazard ratio for ESRD of 2.03 (95% confidence interval, 1.44 to 2.84). Hemoglobin C trait did not associate with prevalent CKD or ESRD. The incidence rate for ESRD among participants with APOL1 high-risk genotypes was 6.6 per 1000 person-years, with a hazard ratio for ESRD of 1.77 (95% confidence interval, 1.31 to 2.38) for participants with, compared with those without, APOL1 high-risk genotypes. In this cohort, SCT strongly associated with risk of progression to ESRD in blacks, and this degree of risk for ESRD was similar to that conferred by APOL1 high-risk genotypes. These results may have important public policy implications for genetic counseling of SCT carriers.

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.

Oxidative Balance Score and the Risk of End-Stage Renal Disease and Cardiovascular Disease.

BACKGROUND: Oxidative balance score (OBS) is a composite measure of oxidative stress-related exposures. The aim of this study was to investigate the association between OBS, end-stage renal disease (ESRD), and cardiovascular disease (CVD). METHODS: Using data from the Chronic Renal Insufficiency Cohort, we calculated the main exposure OBS by summing up 12 apriori-defined pro- and antioxidant factors obtained from the diet history questionnaire and lifestyle assessment. We divided OBS into quartiles (Q1-Q4), with Q1 (predominance of pro-oxidants) as the reference. We analyzed OBS quartiles as an ordinal variable. Crude and adjusted hazards ratios (HRs) and 95% CIs were estimated using Cox proportional hazards models for time to ESRD and CVD. RESULTS: Compared to Q1, Q4 (high antioxidant) was associated with ESRD in the crude model (HR 1.35, 95% CI 1.08-1.69) and adjusting for age, sex, and race (HR 1.36, 95% CI 1.09-1.71) but not in the fully adjusted model (HR 1.12, 95% CI 0.84-1.51). HR of ESRD increased as the OBS quartiles increased in the crude model (ptrend < 0.05) but not in the fully adjusted model (ptrend = 0.30). Compared to Q1, Q4 was associated with CVD in the crude (HR 1.33, 95% CI 1.06-1.68) but not adjusted models. The HR of CVD increased with an increase in OBS quartiles in the crude model (ptrend < 0.05). CONCLUSION: The reverse association between OBS and progression to ESRD suggests that perhaps the effect of oxidative balance-related exposure is different in the setting of established chronic kidney disease.

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.

Waist Circumference, Body Mass Index, and ESRD in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study.

BACKGROUND: The association between waist circumference and end-stage renal disease (ESRD) remains poorly explored. STUDY DESIGN: Longitudinal population-based cohort. SETTING & PARTICIPANTS: Participants in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study (n=30,239) with information for body mass index (BMI), waist circumference, spot urine albumin-creatinine ratio (ACR), and estimated glomerular filtration rate (eGFR; n=26,960). PREDICTOR: Elevated waist circumference or BMI. OUTCOMES & MEASUREMENTS: Incident cases of ESRD were identified through linkage of REGARDS participants with the US Renal Data System. RESULTS: Mean baseline age was 64.8 years, 45.8% were men, and 40.3% were black. Overall, 297 (1.1%) individuals developed ESRD during a median of 6.3 years. After adjustment for all covariates including waist circumference, no significant association was noted between BMI categories and ESRD incidence compared to BMI of 18.5 to 24.9 kg/m2 (referent). Higher waist circumference categories showed significantly increased hazard rates of ESRD, with waist circumference ≥ 108 cm in women and ≥122 cm in men (highest category) showing a 3.97-fold higher hazard rate (95% CI, 2.10-6.86) for ESRD compared to waist circumference < 80 cm in women and <94 cm in men (referent) after adjusting for demographic factors and BMI. However, no significant association was noted between any waist circumference category and ESRD incidence after adjustment for obesity-associated comorbid conditions and baseline ACR and eGFR. LIMITATIONS: Short follow-up period (6.3 years) to assess ESRD risk among adults with eGFRs>60 mL/min/1.73 m2. CONCLUSIONS: In this cohort of older adults, obesity as measured by waist circumference is associated with higher ESRD risk even with adjustment for BMI, whereas obesity as measured by BMI is not associated with higher ESRD risk after adjustment for waist circumference. However, no significant association is noted between increased waist circumference and ESRD risk after adjustment for obesity-related comorbid conditions, eGFR, and ACR.

Flavanone Intake Is Inversely Associated with Risk of Incident Ischemic Stroke in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study.

BACKGROUND: Flavonoids may have beneficial cerebrovascular effects, but evidence from racially and geographically representative cohorts in comprehensive flavonoid databases is lacking. Given racial and geographic disparities in stroke incidence, representative cohort studies are needed. OBJECTIVES: We evaluated the association between flavonoid intake and incident ischemic stroke in a biracial, national cohort using updated flavonoid composition tables and assessed differences in flavonoid intake by sex, race, and region of residence. METHODS: We evaluated 20,024 participants in the REGARDS (REasons for Geographic and Racial Differences in Stroke) study, a biracial prospective study. Participants with stroke history or missing dietary data were excluded. Flavonoid intake was estimated by using a Block98 food frequency questionnaire and the USDA's Provisional Flavonoid Addendum and Proanthocyanidin Database. Associations between quintiles of flavonoid intake and incident ischemic stroke were evaluated by using Cox proportional hazards models, adjusting for confounders. RESULTS: Over 6.5 y, 524 acute ischemic strokes occurred. Flavanone intake was lower in the Southeastern United States but higher in blacks than in whites. After multivariable adjustment, flavanone intake was inversely associated with incident ischemic stroke (HR: 0.72; 95% CI: 0.55, 0.95; P-trend = 0.03). Consumption of citrus fruits and juices was inversely associated with incident ischemic stroke (HR: 0.69; 95% CI: 0.53, 0.91; P-trend = 0.02). Total flavonoids and other flavonoid subclasses were not associated with incident ischemic stroke. There was no statistical interaction with sex, race, or region for any flavonoid measure. CONCLUSIONS: Greater consumption of flavanones, but not total or other flavonoid subclasses, was inversely associated with incident ischemic stroke. Associations did not differ by sex, race, or region for the association; however, regional differences in flavanone intake may contribute to regional disparities in ischemic stroke incidence. Higher flavanone intake in blacks suggests that flavanone intake is not implicated in racial disparities in ischemic stroke incidence.

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.

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.

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.

Validation study of medicare claims to identify older US adults with CKD using the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study.

BACKGROUND: Health care claims data may provide a cost-efficient approach for studying chronic kidney disease (CKD). STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: We compared characteristics and outcomes for individuals with CKD defined using laboratory measurements versus claims data from 6,982 REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study participants who had Medicare fee-for-service coverage. PREDICTORS: Presence of CKD as defined by both the REGARDS Study (CKDREGARDS) and Medicare data (CKDMedicare), presence of CKDREGARDS but not CKDMedicare, and presence of CKDMedicare but not CKDREGARDS, and absence of both CKDREGARDS and CKDMedicare. OUTCOMES: Mortality and incident end-stage renal disease (ESRD). MEASUREMENTS: The research study definition of CKD (CKDREGARDS) included estimated glomerular filtration rate (eGFR) < 60mL/min/1.73m(2) or albumin-creatinine ratio > 30mg/g at the REGARDS Study visit. CKD in Medicare (CKDMedicare) was identified during the 2 years before each participant's REGARDS visit using a claims-based algorithm. RESULTS: Overall, 32% of participants had CKDREGARDS and 6% had CKDMedicare. Sensitivity, specificity, and positive and negative predictive values of CKDMedicare for identifying CKDREGARDS were 15.5% (95% CI, 14.0%-17.1%), 97.7% (95% CI, 97.2%-98.1%), 75.6% (95% CI, 71.4%-79.5%), and 71.5% (95% CI, 70.4%-72.6%), respectively. Mortality and ESRD incidence rates, expressed per 1,000 person-years, were higher for participants with versus without CKDMedicare (mortality: 72.5 [95% CI, 61.3-83.7] vs 33.3 [95% CI, 31.5-35.2]; ESRD: 16.4 [95% CI, 11.2-21.6] vs 1.3 [95% CI, 0.9-1.6]) and with versus without CKDREGARDS (mortality: 59.9 [95% CI, 55.4-64.4] vs 25.5 [95% CI, 23.6-27.4]; ESRD: 6.8 [95% CI, 5.4-8.3] vs 0.1 [95% CI, 0.0-0.3]). Among participants with CKDREGARDS, those with abdominal obesity, diabetes, anemia, lower eGFR, more outpatient visits, hospitalization, and a nephrologist visit in the 2 years before their REGARDS visit were more likely to have CKDMedicare. LIMITATIONS: CKDREGARDS relied on eGFR and albuminuria assessed at a single visit. CONCLUSIONS: CKD, whether defined in claims or through research study measurements, was associated with increased mortality and ESRD. However, individuals with CKD identified in claims may represent a select high-risk population.

Oxidative Balance Score and Chronic Kidney Disease.

BACKGROUND: The oxidative balance score (OBS) is a composite estimate of the overall pro- and antioxidant exposure status in an individual. The aim of this study was to determine the association between OBS and renal disease. METHODS: Using the Reasons for Geographic and Racial Differences in Stroke cohort study, OBS was calculated by combining 13 a priori-defined pro- and antioxidant factors by using baseline dietary and lifestyle assessment. OBS was divided into quartiles (Q1-Q4) with the lowest quartile, Q1 (predominance of pro-oxidants), as the reference. Multivariable logistic regression and Cox proportional hazards models were used to estimate adjusted ORs for albuminuria defined as urine albumin/creatinine ratio (ACR)>30 mg/g, macroalbuminuria defined as ACR>300 mg/g and chronic kidney disease (CKD) defined as estimated glomerular filtration rate<60 ml/min/1.73 m2 according to the Chronic Kidney Disease Epidemiology Collaboration and hazards ratios for end-stage renal disease (ESRD), respectively. RESULTS: Of the 19,461 participants analyzed, 12.9% had albuminuria and 10.1% had CKD at baseline; over a median follow-up of 3.5 years (range 2.14-4.32 years), 0.46% developed ESRD. Higher OBS quartiles were associated with lower prevalence of CKD (OR vs. Q1: Q2=0.93 [95% CI 0.80-1.08]; Q3=0.90 [95% CI 0.77-1.04] and Q4=0.79 [95% CI 0.67-0.92], p for trend<.01). The associations between OBS and albuminuria (p for trend 0.31) and incident ESRD (p for trend 0.56) were not significant in the fully adjusted models. CONCLUSIONS: These findings suggest that higher OBS is associated with lower prevalence of CKD. Lack of association with ESRD incidence in the multivariable analyses indicates that temporal relation between OBS and renal damage remains unclear.

Comparison of quality-of-care measures in U.S. patients with end-stage renal disease secondary to lupus nephritis vs. other causes.

BACKGROUND: Patients with end-stage renal disease (ESRD) due to lupus nephritis (LN-ESRD) may be followed by multiple providers (nephrologists and rheumatologists) and have greater opportunities to receive recommended ESRD-related care. We aimed to examine whether LN-ESRD patients have better quality of ESRD care compared to other ESRD patients. METHODS: Among incident patients (7/05-9/11) with ESRD due to LN (n = 6,594) vs. other causes (n = 617,758), identified using a national surveillance cohort (United States Renal Data System), we determined the association between attributed cause of ESRD and quality-of-care measures (pre-ESRD nephrology care, placement on the deceased donor kidney transplant waitlist, and placement of permanent vascular access). Multivariable logistic and Cox proportional hazards models were used to estimate adjusted odds ratios (ORs) and hazard ratios (HRs). RESULTS: LN-ESRD patients were more likely than other ESRD patients to receive pre-ESRD care (71% vs. 66%; OR = 1.68, 95% CI 1.57-1.78) and be placed on the transplant waitlist in the first year (206 vs. 86 per 1000 patient-years; HR = 1.42, 95% CI 1.34-1.52). However, only 24% had a permanent vascular access (fistula or graft) in place at dialysis start (vs. 36%; OR = 0.63, 95% CI 0.59-0.67). CONCLUSIONS: LN-ESRD patients are more likely to receive pre-ESRD care and have better access to transplant, but are less likely to have a permanent vascular access for dialysis, than other ESRD patients. Further studies are warranted to examine barriers to permanent vascular access placement, as well as morbidity and mortality associated with temporary access, in patients with LN-ESRD.

Factors affecting willingness to receive a kidney transplant among minority patients at an urban safety-net hospital: a cross-sectional survey.

BACKGROUND: In the US, African Americans (AAs) are four times more likely to develop end stage renal disease (ESRD) but half as likely to receive a kidney transplant as whites. Patient interest in kidney transplantation is a fundamental step in the kidney transplant referral process. Our aim was to determine the factors associated with the willingness to receive a kidney transplant among chronic kidney disease (CKD) patients in a predominantly minority population. METHODS: CKD patients from an outpatient nephrology clinic at a safety-net hospital (n = 213) participated in a cross-sectional survey from April to June, 2013 to examine the factors associated with willingness to receive a kidney transplant among a predominantly minority population. The study questionnaire was developed from previously published literature. Multivariable logistic regression analysis was used to determine factors associated with willingness to undergo a kidney transplant. RESULTS: Respondents were primarily AAs (91.0%), mostly female (57.6%) and middle aged (51.6%). Overall, 53.9% of participants were willing to undergo a kidney transplant. Willingness to undergo a kidney transplant was associated with a positive perception towards living kidney donation (OR 7.31, 95% CI: 1.31-40.88), willingness to attend a class about kidney transplant (OR = 7.15, CI: 1.76-29.05), perception that a kidney transplant will improve quality of life compared to dialysis (OR = 5.40, 95% CI: 1.97-14.81), and obtaining information on kidney transplant from other sources vs. participant's physician (OR =3.30, 95% CI: 1.13-9.67), when compared with their reference groups. CONCLUSION: It is essential that the quality of life benefits of kidney transplantation be known to individuals with CKD to increase their willingness to undergo kidney transplantation. Availability of multiple sources of information and classes on kidney transplantation may also contribute to willingness to undergo kidney transplantation, especially among AAs.

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.

Family history of stroke and cardiovascular health in a national cohort.

BACKGROUND: We investigated the association between family history of stroke (FHS) and Life's Simple 7 (LS7), a public health metric defined by the American Heart Association. METHODS: Reasons for Geographic and Racial Differences in Stroke is a national population-based cohort of 30,239 blacks and whites, aged 45 years or older, sampled from the US population between 2003 and 2007. Data were collected by telephone, mail questionnaires, and in-home examinations. FHS was defined as any first-degree relative with stroke. Levels of the LS7 components (total cholesterol, blood pressure, fasting glucose, physical activity, diet, smoking, and body mass index) were each coded as poor (0 points), intermediate (1 point), or ideal (2 points) health. Ordinal logistic regression was used to model the data. RESULTS: Among 20,567 subjects with complete LS7 and FHS data, there were 7702 (37%) participants with an FHS. The mean age of the participants was 64 years. The mean (± standard deviation) overall LS7 score was lower for blacks (6.5 ± 2.0) than that of whites (7.6 ± 2.1). FHS was associated with poorer levels of physiological factors, particularly high blood pressure (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.07-1.19) and inversely associated with behaviors such as smoking (OR, .92; 95% CI, .85-.99). CONCLUSIONS: Our results suggest that screening for FHS can provide an opportunity for earlier detection and management of modifiable risk factors.

Relative risks of chronic kidney disease for mortality and end-stage renal disease across races are similar.

Some suggest race-specific cutpoints for kidney measures to define and stage chronic kidney disease (CKD), but evidence for race-specific clinical impact is limited. To address this issue, we compared hazard ratios of estimated glomerular filtration rates (eGFR) and albuminuria across races using meta-regression in 1.1 million adults (75% Asians, 21% Whites, and 4% Blacks) from 45 cohorts. Results came mainly from 25 general population cohorts comprising 0.9 million individuals. The associations of lower eGFR and higher albuminuria with mortality and end-stage renal disease (ESRD) were largely similar across races. For example, in Asians, Whites, and Blacks, the adjusted hazard ratios (95% confidence interval) for eGFR 45-59 versus 90-104 ml/min per 1.73 m(2) were 1.3 (1.2-1.3), 1.1 (1.0-1.2), and 1.3 (1.1-1.7) for all-cause mortality, 1.6 (1.5-1.7), 1.4 (1.2-1.7), and 1.4 (0.7-2.9) for cardiovascular mortality, and 27.6 (11.1-68.7), 11.2 (6.0-20.9), and 4.1 (2.2-7.5) for ESRD, respectively. The corresponding hazard ratios for urine albumin-to-creatinine ratio 30-299 mg/g or dipstick 1+ versus an albumin-to-creatinine ratio under 10 or dipstick negative were 1.6 (1.4-1.8), 1.7 (1.5-1.9), and 1.8 (1.7-2.1) for all-cause mortality, 1.7 (1.4-2.0), 1.8 (1.5-2.1), and 2.8 (2.2-3.6) for cardiovascular mortality, and 7.4 (2.0-27.6), 4.0 (2.8-5.9), and 5.6 (3.4-9.2) for ESRD, respectively. Thus, the relative mortality or ESRD risks of lower eGFR and higher albuminuria were largely similar among three major races, supporting similar clinical approach to CKD definition and staging, across races.

Incident ESRD among participants in a lead surveillance program.

BACKGROUND: Very high levels of lead can cause kidney failure; data about renal effects at lower levels are limited. STUDY DESIGN: Cohort study, external (vs US population) and internal (by exposure level) comparisons. SETTINGS & PARTICIPANTS: 58,307 men in an occupational surveillance system in 11 US states. PREDICTOR: Blood lead levels. OUTCOME: Incident end-stage renal disease determined by matching the cohort with the US Renal Data System (n=302). MEASUREMENTS: Blood lead categories were 0-<5, 5-<25, 25-<40, 40-51, and >51 µg/dL, defined by highest blood lead test result. One analysis for those with data for race (31% of cohort) and another for the whole cohort after imputing race. RESULTS: Median follow-up was 12 years. Among those with race information, the end-stage renal disease standardized incidence ratio (SIR; US population as referent) was 1.08 (95% CI, 0.89-1.31) overall. The SIR in the highest blood lead category was 1.47 (95% CI, 0.98-2.11), increasing to 1.56 (95% CI, 1.02-2.29) for those followed up for 5 or more years. For the entire cohort (including those with race imputed), the overall SIR was 0.92 (95% CI, 0.82-1.03), increasing to 1.36 (95% CI, 0.99-1.73) in the highest blood lead category (SIR of 1.43 [95% CI, 1.01-1.85] in those with ≥5 years' follow-up). In internal analyses by Cox regression, rate ratios for those with 5 or more years' follow-up in the entire cohort were 1.0 (0-<5 and 5-<25 µg/dL categories combined) and 0.92, 1.08, and 1.96 for the 25-<40, 40-51, and >51 µg/dL categories, respectively (P for trend=0.003). The effect of lead was strongest in nonwhites. LIMITATIONS: Lack of detailed work history, reliance on only a few blood lead tests per person to estimate level of exposure, lack of clinical data at time of exposure. CONCLUSIONS: Data suggest that current US occupational limits on blood lead levels may need to be strengthened to avoid kidney disease.

Dietary patterns and risk of death and progression to ESRD in individuals with CKD: a cohort study.

BACKGROUND: Nutrition is linked strongly with health outcomes in chronic kidney disease (CKD). However, few studies have examined relationships between dietary patterns and health outcomes in persons with CKD. STUDY DESIGN: Observational cohort study. SETTING & PARTICIPANTS: 3,972 participants with CKD (defined as estimated glomerular filtration rate < 60 mL/min/1.73 m2 or albumin-creatinine ratio ≥ 30 mg/g at baseline) from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study, a prospective cohort study of 30,239 black and white adults at least 45 years of age. PREDICTORS: 5 empirically derived dietary patterns identified by factor analysis: "convenience" (Chinese and Mexican foods, pizza, and other mixed dishes), "plant-based" (fruits and vegetables), "sweets/fats" (sugary foods), "Southern" (fried foods, organ meats, and sweetened beverages), and "alcohol/salads" (alcohol, green-leafy vegetables, and salad dressing). OUTCOMES: All-cause mortality and end-stage renal disease (ESRD). RESULTS: 816 deaths and 141 ESRD events were observed over approximately 6 years of follow-up. There were no statistically significant associations of convenience, sweets/fats, or alcohol/salads pattern scores with all-cause mortality after multivariable adjustment. In Cox regression models adjusted for sociodemographic factors, energy intake, comorbid conditions, and baseline kidney function, higher plant-based pattern scores (indicating greater consistency with the pattern) were associated with lower risk of mortality (HR comparing fourth to first quartile, 0.77; 95% CI, 0.61-0.97), whereas higher Southern pattern scores were associated with greater risk of mortality (HR comparing fourth to first quartile, 1.51; 95% CI, 1.19-1.92). There were no associations of dietary patterns with incident ESRD in multivariable-adjusted models. LIMITATIONS: Missing dietary pattern data, potential residual confounding from lifestyle factors. CONCLUSIONS: A Southern dietary pattern rich in processed and fried foods was associated independently with mortality in persons with CKD. In contrast, a diet rich in fruits and vegetables appeared to be protective.