Predictors of Acute Kidney Injury (AKI) among COVID-19 Patients at the US Department of Veterans Affairs: The Important Role of COVID-19 Vaccinations.

BACKGROUND: There are knowledge gaps about factors associated with acute kidney injury (AKI) among COVID-19 patients. To examine AKI predictors among COVID-19 patients, a retrospective longitudinal cohort study was conducted between January 2020 and December 2022. Logistic regression models were used to examine predictors of AKI, and survival analysis was performed to examine mortality in COVID-19 patients. RESULTS: A total of 742,799 veterans diagnosed with COVID-19 were included and 95,573 were hospitalized within 60 days following COVID-19 diagnosis. A total of 45,754 developed AKI and 28,573 AKI patients were hospitalized. Use of vasopressors (OR = 14.73; 95% CL 13.96-15.53), history of AKI (OR = 2.22; CL 2.15-2.29), male gender (OR = 1.90; CL 1.75-2.05), Black race (OR = 1.62; CL 1.57-1.65), and age 65+ (OR = 1.57; CL 1.50-1.63) were associated with AKI. Patients who were vaccinated twice and boosted were least likely to develop AKI (OR = 0.51; CL 0.49-0.53) compared to unvaccinated COVID-19 patients. Patients receiving two doses (OR = 0.77; CL = 0.72-0.81), or a single dose (OR = 0.88; CL = 0.81-0.95) were also less likely to develop AKI compared to the unvaccinated. AKI patients exhibited four times higher mortality compared to those without AKI (HR = 4.35; CL 4.23-4.50). Vaccinated and boosted patients had the lowest mortality risk compared to the unvaccinated (HR = 0.30; CL 0.28-0.31). CONCLUSION: Use of vasopressors, being unvaccinated, older age, male gender, and Black race were associated with post COVID-19 AKI. Whether COVID-19 vaccination, including boosters, decreases the risk of developing AKI warrants additional studies.

Dialysis Care for US Military Veterans in Puerto Rico during the 2017 Atlantic Hurricane Season.

OBJECTIVES: Patients with end stage kidney disease (ESKD) are at higher risk for increased mortality and morbidity due to disaster-related disruptions to care. We examine effects of Hurricanes Irma and Maria on access to dialysis care for US Department of Veterans Affairs (VA) ESKD patients in Puerto Rico. METHODS: A retrospective, longitudinal cohort study was conducted among VA patients with at least 1 dialysis-related encounter between September 6, 2016, and September 5, 2018. The annual number of dialysis encounters, visits to an emergency department (ED), and the number of deaths pre- and post-hurricanes were compared. A random effects logistic regression model for correlated binary outcomes was fitted for predictors of mortality. Chi-square tests were for differences between pre- and post-hurricane visits. RESULTS: The number of ED visits increased in post-hurricane period (1172 [5.7%] to 1195 [6.6%]; P < 0.001). ESKD-related ED visits increased from 200 (0.9%) to 227 (1.3%) (P < 0.05). Increase in mortality was associated with age (OR = 1.66; CI: 1.23-2.17), heart failure (OR = 2.07; CI: 1.26-3.40), chronic pulmonary disease (OR = 3.26; CI: 1.28-8.28), and sepsis (OR = 3.16; CI: 1.89-5.29). CONCLUSIONS: There was an increase in dialysis services at the San Juan VA Medical Center post-Irma/Maria, and access to dialysis care at the non-VA clinics was limited. The role of VA dialysis centers in providing care during disasters warrants further investigation.

Using an Administrative and Clinical Database to Determine the Early Spread of COVID-19 at the US Department of Veterans Affairs during the Beginning of the 2019-2020 Flu Season: A Retrospective Longitudinal Study.

BACKGROUND: Previous studies examining the early spread of COVID-19 have used influenza-like illnesses (ILIs) to determine the early spread of COVID-19. We used COVID-19 case definition to identify COVID-like symptoms (CLS) independently of other influenza-like illnesses (ILIs). METHODS: Using data from Emergency Department (ED) visits at VA Medical Centers in CA, TX, and FL, we compared weekly rates of CLS, ILIs, and non-influenza ILIs encounters during five consecutive flu seasons (2015-2020) and estimated the risk of developing each illness during the first 23 weeks of the 2019-2020 season compared to previous seasons. RESULTS: Patients with CLS were significantly more likely to visit the ED during the first 23 weeks of the 2019-2020 compared to prior seasons, while ED visits for influenza and non-influenza ILIs did not differ substantially. Adjusted CLS risk was significantly lower for all seasons relative to the 2019-2020 season: RR15-16 = 0.72, 0.75, 0.72; RR16-17 = 0.81, 0.77, 0.79; RR17-18 = 0.80, 0.89, 0.83; RR18-19 = 0.82, 0.96, 0.81, in CA, TX, and FL, respectively. CONCLUSIONS: The observed increase in ED visits for CLS indicates the likely spread of COVID-19 in the US earlier than previously reported. VA data could potentially help identify emerging infectious diseases and supplement existing syndromic surveillance systems.

Disparities in Excess, All-Cause Mortality among Black, Hispanic, and White Veterans at the U.S. Department of Veterans Affairs during the COVID-19 Pandemic.

BACKGROUND: From 2019 to 2020, all-cause mortality in the U.S. increased, with most of the rise attributed to COVID-19. No studies have examined the racial disparities in all-cause mortality among U.S. veterans receiving medical care (VA users) at the U.S. Department of Veterans Affairs (VA) during the pandemic. METHODS: In the present paper, we conduct a longitudinal study examining the differences in mortality among White, Black, and Hispanic veterans, aged 45 years and older, during the first, full year of the pandemic (March 2020-February 2021). We calculated the Standardized Mortality Rates (SMRs) per 100,000 VA users for each racial and ethnic group by age and gender. RESULTS: The highest percentage increase between the number of deaths occurred between pre- and post-pandemic years (March 2020-February 2021 vs. March 2019-February 2020). For Hispanics, the all-cause mortality increased by 34%, while for Blacks, it increased by 32%. At the same time, we observed that an 18% increase in all-cause mortality occurred among Whites. CONCLUSION: Blacks and Hispanics were disproportionately affected by the COVID-19 pandemic, leading both directly and indirectly to higher all-cause mortality among these groups compared to Whites. Disparities in the all-cause mortality rates varied over time and across groups. Additional research is needed to examine which factors may account for the observed changes over time. Understanding those factors will permit the development of strategies to mitigate these disparities.

Access to Care for VA Dialysis Patients During Superstorm Sandy.

Introduction: This study examines the use of dialysis services by end-stage renal disease (ESRD) patients following the Superstorm Sandy-related, months-long closure of the New York campus of the US Department of Veterans Affairs (VA) New York Harbor VA Healthcare System (NYHHS, Manhattan VAMC). Methods: Outpatient visits, dialysis care, emergency department visits, and hospitalizations at VA and non-VA facilities for 47 Manhattan VAMC ESRD patients were examined 12 months pre- and post-Sandy using VA administrative and clinical data. Results: The Brooklyn campus of NYHHS, which is within ten miles of Manhattan VAMC, experienced the largest increase in the number of dialysis encounters after the closure. Dialysis encounters for VA patients also increased at non-VA facilities, rising on average, to 106 per month. For the James J Peters Bronx VAMC, the number of total dialysis encounters for Manhattan VAMC patients fluctuated between 39 and 43 per month, dropping to less than 30 after the Manhattan VAMC dialysis unit reopened. Conclusion: Manhattan VAMC ESRD patients used nearby alternate VA sites and non-VA clinics for their care during the closure of the Manhattan VAMC dialysis unit. The VA electronic health records played an important role in ensuring continuity of care for patients who exclusively used VAMC facilities post-Sandy because patient information was immediately accessible at other VA facilities. The events related to Superstorm Sandy highlight the need for dialysis providers to have a comprehensive disaster plan, including nearby alternate care sites that can increase service capacity when a dialysis facility is closed because of a disaster.

Impact of the Aliso Canyon Gas Leak on Respiratory-Related Conditions Among US Department of Veterans Affairs (VA) Users.

BACKGROUND: The largest gas leak in United States history occurred October 2015 through February 2016 near Porter Ranch (PR), California, and prompted the temporary relocation of nearby residents because of health concerns related to natural gas exposure. METHODS: A retrospective cohort study was conducted using US Department of Veterans Affairs (VA) administrative and clinical data. On the basis of zip codes, we created two groups: PR (1920 patients) and San Fernando Valley (SFV) (15 260 patients) and examined the proportion of outpatient visits to VA providers with respiratory-related diagnoses between October 2014 and September 2017. RESULTS: We observed an increase in the proportion of visits in the PR group during the leak (7.0% vs 6.1%, P<0.005) and immediately after the leak (7.7% vs 5.3%, P<0.0001). For both groups, we observed a decrease in respiratory diagnoses one year after the leak (7.0% to 5.9%, P<0.05 PR; 6.1% to 5.7%, P<0.01 SFV). CONCLUSION: Exposure to natural gas likely led to the observed increase in respiratory-related diagnoses during and after the PR gas leak. Early relocation following natural gas leaks may mitigate respiratory exacerbations. (Disaster Med Public Health Preparedness. 2019;13:419-423).

Seeking Information from the VA During Natural Disasters.

The purpose of this study is to identify factors influencing patient preferences for communication from the US Department of Veterans Affairs (VA) during natural disasters. The 37-question, probability-based survey collected data from 2,264 VA users living in the Northeast US logistic regression analyses were conducted for top four modalities, and age was identified as the most important predictor of communication preferences. The findings suggest that the use of multiple modalities, such as telephone, television, radio, text, and email is necessary to successfully disseminate information and effectively reach all VA patients in the event of large-scale emergencies.

Nutritional predictors of early mortality in incident hemodialysis patients.

PURPOSE: Low serum albumin concentration and low dietary protein intake are associated with protein-energy wasting (PEW) and higher mortality in maintenance hemodialysis patients. The role of these nutritional markers is less clear in clinical outcomes of the first several months of dialysis therapy, where mortality is exceptionally high. METHODS: In a cohort of 17,445 incident hemodialysis patients, we examined variation in serum albumin and the normalized protein catabolic rate (nPCR), a surrogate of dietary intake, and quarterly mortality in the first 2 years of dialysis therapy. Cox proportional hazard models were fitted to estimate the association between mortality and combined albumin/nPCR categories for eight quarters. We investigated the associations between mortality and baseline and subsequent serum albumin levels per cohort quarter as well as changes in albumin and nPCR over time. RESULTS: Patients were 64 ± 15 years old (mean ± SD) and included 45 % women, 24 % African Americans and 58 % diabetics. Correlations between quarterly serum albumin and nPCR varied from 0.18 to 0.25. Serum albumin <3.5 g/dL was consistently associated with high mortality as was nPCR <1 g/kg/day (except for qtr1). Low serum albumin and nPCR greater than 0.2 g/dLg/dL or g/kg/day, respectively, were associated with increased risk of death. Quarterly rise in nPCR (>+0.2 g/kg/day) showed reverse effect on mortality from the 2nd to the last quarter. CONCLUSIONS: Low serum albumin and nPCR are associated with mortality. A rapid rise in nPCR by the end of the second year may indicate pre-existing PEW.

Iron indices and survival in maintenance hemodialysis patients with and without polycystic kidney disease.

BACKGROUND: Anemia is less prominent in patients with polycystic kidney disease (PKD). Such iron indices as ferritin and transferrin saturation (TSAT) values are used to guide management of anemia in individuals on maintenance hemodialysis (MHD). Optimal levels of correction of anemia and optimal levels of TSAT and ferritin are unclear in chronic kidney disease patients and have not been studied specifically in PKD. METHODS: We studied 2969 MHD patients with and 128 054 patients without PKD from 580 outpatient hemodialysis facilities between July 2001 and June 2006. Using baseline, time-dependent and time-averaged values with unadjusted and multivariable adjusted analysis models, the survival predictabilities of TSAT and ferritin were studied. RESULTS: PKD patients were 58 ± 13 years old and included 46% women, whereas non-PKD patients were 62 ± 15 years old and 45% women. In both PKD and non-PKD patients, a time-averaged TSAT between 30 and 40% was associated with the lowest mortality. Time-averaged ferritin between 100 and <800 ng/mL was associated with the lowest mortality in PKD patients, although this range was 500 to <800 ng/mL in non-PKD patients. CONCLUSIONS: In MHD patients with and without PKD, there was a U-shaped relationship between the average TSAT and mortality, and a TSAT of 30-40% was associated with the best survival. However, an average ferritin of 100-800 ng/mL was associated with the best survival in PKD patients, whereas that of non-PKD patients was 500-800 ng/mL. Further studies in PKD and non-PKD patients are necessary to determine whether or not therapeutic attempts to keep TSAT and ferritin levels in these ranges will improve survival.

Serum creatinine level, a surrogate of muscle mass, predicts mortality in peritoneal dialysis patients.

BACKGROUND: In hemodialysis patients, higher serum creatinine (Cr) concentration represents larger muscle mass and predicts greater survival. However, this association remains uncertain in peritoneal dialysis (PD) patients. METHODS: In a cohort of 10 896 PD patients enrolled from 1 July 2001 to 30 June 2006, the association of baseline serum Cr level and change during the first 3 months after enrollment with all-cause mortality was examined. RESULTS: The cohort mean ± SD age was 55 ± 15 years old and included 52% women, 24% African-Americans and 48% diabetics. Compared with patients with serum Cr levels of 8.0-9.9 mg/dL, patients with serum Cr levels of <4.0 mg/dL and 4.0-5.9 mg/dL had higher risks of death {HR 1.36 [95% confidence interval (95% CI) 1.19-1.55] and 1.19 (1.08-1.31), respectively} whereas patients with serum Cr levels of 10.0-11.9 mg/dL, 12.0-13.9 mg/dL and ≥14.0 mg/dL had lower risks of death (HR 0.88 [95% CI 0.79-0.97], 0.71 [0.62-0.81] and 0.64 [0.55-0.75], respectively) in the fully adjusted model. Decrease in serum Cr level over 1.0 mg/dL during the 3 months predicted an increased risk of death additionally. The serum Cr-mortality association was robust in patients with PD treatment duration of ≥12 months, but was not observed in those with PD duration of <3 months. CONCLUSIONS: Muscle mass reflected in serum Cr level may be associated with survival even in PD patients. However, the serum Cr-mortality association is attenuated in the early period of PD treatment, suggesting competing effect of muscle mass versus residual renal function on mortality.

Comparing mortality of peritoneal and hemodialysis patients in the first 2 years of dialysis therapy: a marginal structural model analysis.

BACKGROUND AND OBJECTIVES: There are conflicting research results about the survival differences between hemodialysis and peritoneal dialysis, especially during the first 2 years of dialysis treatment. Given the challenges of conducting randomized trials, differential rates of modality switch and transplantation, and time-varying confounding in cohort data during the first years of dialysis treatment, use of novel analytical techniques in observational cohorts can help examine the peritoneal dialysis versus hemodialysis survival discrepancy. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study examined a cohort of incident dialysis patients who initiated dialysis in DaVita dialysis facilities between July of 2001 and June of 2004 and were followed for 24 months. This study used the causal modeling technique of marginal structural models to examine the survival differences between peritoneal dialysis and hemodialysis over the first 24 months, accounting for modality change, differential transplantation rates, and detailed time-varying laboratory measurements. RESULTS: On dialysis treatment day 90, there were 23,718 incident dialysis-22,360 hemodialysis and 1,358 peritoneal dialysis-patients. Incident peritoneal dialysis patients were younger, had fewer comorbidities, and were nine and three times more likely to switch dialysis modality and receive kidney transplantation over the 2-year period, respectively, compared with hemodialysis patients. In marginal structural models analyses, peritoneal dialysis was associated with persistently greater survival independent of the known confounders, including dialysis modality switch and transplant censorship (i.e., death hazard ratio of 0.52 [95% confidence limit 0.34-0.80]). CONCLUSIONS: Peritoneal dialysis seems to be associated with 48% lower mortality than hemodialysis over the first 2 years of dialysis therapy independent of modality switches or differential transplantation rates.

Patterns and predictors of early mortality in incident hemodialysis patients: new insights.

BACKGROUND: Incident hemodialysis patients have the highest mortality in the first several months after starting dialysis treatments. We hypothesized that the patterns and risk factors associated with this early mortality differ from those in later dialysis therapy periods. METHODS: We examined mortality patterns and predictors during the first several months of hemodialysis treatment in 18,707 incident patients since the first week of hemodialysis therapy and estimated the population attributable fractions for selected time periods in the first 24 months. RESULTS: The 18,707 incident hemodialysis patients were 45% women and 54% diabetics. The standardized mortality ratios (95% confidence interval) in the 1st to 3rd month of hemodialysis therapy were 1.81 (1.74-1.88), 1.79 (1.72-1.86), and 1.34 (1.27-1.40), respectively. The standardized mortality ratio reached prevalent mortality only by the 7th month. No survival advantage for African Americans existed in the first 6 months. Patients with low albumin <3.5 g/dl had the highest proportion of infection-related deaths while patients with higher albumin levels had higher cardiovascular deaths including 76% of deaths during the first 3 months. Use of catheter as vascular access and hypoalbuminemia <3.5 g/dl explained 34% (17-54%) and 33% (19-45%) of all deaths in the first 90 days, respectively. CONCLUSIONS: Incident hemodialysis patients have the highest mortality during the first 6 months including 80% higher death risk in the first 2 months. The presence of a central venous catheter and hypoalbuminemia <3.5 g/dl each explain one third of all deaths in the first 90 days.

Hemoglobin level and survival in hemodialysis patients with polycystic kidney disease and the role of administered erythropoietin.

Interventional trials indicate adverse outcomes when hemoglobin >13 g/dL is targeted in patients with chronic kidney disease (CKD) who receive erythropoiesis-stimulating agents (ESAs). It is not clear whether high-achieved hemoglobin with minimal to no ESA administration as observed in some patients with polycystic kidney disease (PKD) is also associated with poor outcomes. Survival models were examined to assess the association between hemoglobin increments and mortality in a 6-year cohort of 2,402 PKD and 110,875 non-PKD hemodialysis patients across infrequent versus frequent ESA therapy defined as ESA < 25% of cohort time versus otherwise, respectively. Mortality risk was estimated by Cox proportional regression [hazard ratio (HR) and 95% of confidence interval] analysis. Patients with PKD were aged 58 ± 13 years and included 46% women 14% Blacks, respectively. Fully adjusted death HRs of time-averaged hemoglobin increments <11.0, 12.0 to <13.0 g/dL (reference: 11.0 to <12.0 g/dL) for frequent ESA therapy were 2.57 (1.48-4.48), 0.60 (0.43-0.82), and 0.81 (0.50-1.29), whereas for infrequent ESA therapy they were 1.33 (0.47-3.78), 0.28 (0.13-0.61), and 0.22 (0.09-0.57), respectively. Hence, in patients with PKD who require infrequent ESA, incrementally higher achieved hemoglobin including > 13.0 g/dL exhibits better survival; this incremental survival gain of higher hemoglobin is not observed in patients with PKD receiving frequent ESA administration, in whom hemoglobin concentration > 13 exhibits increased mortality.

Relationship of body size and initial dialysis modality on subsequent transplantation, mortality and weight gain of ESRD patients.

BACKGROUND: Whether peritoneal dialysis (PD) treatment leads to greater weight gain than with hemodialysis (HD) and if this limits access of obese end-stage renal disease patients to renal transplantation has not been examined. We undertook this study to determine the interrelationship between body size and initial dialysis modality on transplantation, mortality and weight gain. METHODS: Time to transplantation, time to death and weight gain were estimated in a 1:1 propensity score-matched cohort of incident HD and PD patients treated in facilities owned by DaVita Inc. between 1 July 2001 through 30 June 2006 followed through 30 June 2007 (4008 pairs) in four strata of body mass index (BMI) (<18.5, 18.5-24.99, 25.00-29.99 and ≥ 30 kg/m(2)). RESULTS: Transplantation was significantly more likely in PD patients [adjusted hazards ratio (aHR) 1.48, 95% confidence interval (95% CI) 1.29-1.70]; the probability of receiving a kidney transplant was significantly higher in each strata of BMI >18.5 kg/m(2), including with BMI ≥ 30 kg/m(2) (aHR 1.45, 95% CI 1.11-1.89). PD patients had significantly lower all-cause mortality for patients with BMI 18.50-29.99 kg/m(2). Both these findings were confirmed on analyses of the entire unmatched incident cohort (PD 4008; HD 58 471). The effect of dialysis modality on weight gain was tested in 687 propensity score-matched pairs; the odds of >2, >5 or >10% weight gain were significantly lower in PD patients. CONCLUSION: Treatment with PD is less likely to be associated with a significant weight gain and does not limit the access of obese patients to renal transplantation.

Mortality prediction by surrogates of body composition: an examination of the obesity paradox in hemodialysis patients using composite ranking score analysis.

In hemodialysis patients, lower body mass index and weight loss have been associated with higher mortality rates, a phenomenon sometimes called the obesity paradox. This apparent paradox might be explained by loss of muscle mass. The authors thus examined the relation to mortality of changes in dry weight and changes in serum creatinine levels (a muscle-mass surrogate) in a cohort of 121,762 hemodialysis patients who were followed for up to 5 years (2001-2006). In addition to conventional regression analyses, the authors conducted a ranking analysis of joint effects in which the sums and differences of the percentiles of change for the 2 measures in each patient were used as the regressors. Concordant with previous body mass index observations, lower body mass, lower muscle mass, weight loss, and serum creatinine decline were associated with higher death rates. Among patients with a discordant change, persons whose weight declined but whose serum creatinine levels increased had lower death rates than did those whose weight increased but whose serum creatinine level declined. A decline in serum creatinine appeared to be a stronger predictor of mortality than did weight loss. Assuming residual selection bias and confounding were not large, the present results suggest that a considerable proportion of the obesity paradox in dialysis patients might be explained by the amount of decline in muscle mass.

Mineral and bone disorders and survival in hemodialysis patients with and without polycystic kidney disease.

BACKGROUND: Maintenance hemodialysis (MHD) patients with polycystic kidney disease (PKD) have better survival than non-PKD patients. Mineral and bone disorders (MBD) are associated with accelerated atherosclerosis and cardiovascular death in MHD patients. It is unknown whether the different MBD mortality association between MHD populations with and without PKD can explain the survival differential. METHODS: Survival models were examined to assess the association between different laboratory markers of MBD [such as serum phosphorous, parathyroid hormone (PTH), calcium and alkaline phosphatase] and mortality in a 6-year cohort of 60,089 non-PKD and 1501 PKD MHD patients. RESULTS: PKD and non-PKD patients were 57±13 and 62±15 years old and included 46 and 45% women and 14 and 32% Blacks, respectively. Whereas PKD individuals with PTH 150 to <300 pg/mL (reference) had the lowest risk for mortality, the death risk was higher in patients with PTH<150 [hazard ratio (HR): 2.16 (95% confidence interval 1.53-3.06)], 300 to <600 [HR: 1.30 (0.97-1.74)] and ≥600 pg/mL [HR: 1.46 (1.02-2.08)], respectively. Similar patterns were found in non-PKD patients. Fully adjusted death HRs of time-averaged serum phosphorous increments<3.5, 5.5 to <7.5 and ≥7.5 mg/dL (reference: 3.5 to <5.5 mg/dL) for PKD patients were 2.82 (1.50-5.29), 1.40 (1.12-1.75) and 2.25 (1.57-3.22). The associations of alkaline phosphatase and calcium with mortality were similar in PKD and non-PKD patients. CONCLUSION: Bone-mineral disorder markers exhibit similar mortality trends between PKD and non-PKD MHD patients, although some differences are observed in particular in low PTH and phosphorus ranges.

Dialysis modality and outcomes in kidney transplant recipients.

BACKGROUND AND OBJECTIVES: The influence of pretransplant dialysis modality on post-transplant outcomes is not clear. This study examined associations of pretransplant dialysis modality with post-transplant outcomes in a large national cohort of kidney transplant recipients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Linking the 5-year patient data of a large dialysis organization to the Scientific Registry of Transplant Recipients, 12,416 hemodialysis and 2092 peritoneal dialysis patients who underwent first kidney transplantation were identified. Mortality or graft failure and delayed graft function risks were estimated by Cox regression (hazard ratio) and logistic regression (odds ratio), respectively. RESULTS: Recipients treated with peritoneal dialysis pretransplantation had lower (21.9/1000 patient-years [95% confidence interval: 18.1-26.5]) crude all-cause mortality rate than those recipients treated with hemodialysis (32.8/1000 patient-years [30.8-35.0]). Pretransplant peritoneal dialysis use was associated with 43% lower adjusted all-cause and 66% lower cardiovascular death. Furthermore, pretransplant peritoneal dialysis use was associated with 17% and 36% lower unadjusted death-censored graft failure and delayed graft function risk, respectively. However, after additional adjustment for relevant covariates, pretransplant peritoneal dialysis modality was not a significant predictor of death-censored graft failure delayed graft function, respectively. Similar trends were noted on analyses using a propensity score matched cohort of 2092 pairs of patients. CONCLUSIONS: Compared with hemodialysis, patients treated with peritoneal dialysis before transplantation had lower mortality but similar graft loss or delayed graft function. Confounding by residual selection bias cannot be ruled out.

Blood pressure and survival in long-term hemodialysis patients with and without polycystic kidney disease.

BACKGROUND: In maintenance dialysis patients, low blood pressure (BP) values are associated with higher death rates when compared with normal to moderately high values. This 'hypertension paradox' may be related to comorbid conditions. Dialysis patients with polycystic kidney disease (PKD) usually have a lower comorbidity burden and greater survival. We hypothesized that in PKD dialysis patients, a representative of a healthier dialysis patient population, high BP is associated with higher mortality. METHODS: Time-dependent survival models including after multivariate adjustment were examined to assess the association between prehemodialysis and posthemodialysis BP and all-cause mortality in a 5-year cohort of 67 085 non-PKD and 1579 PKD hemodialysis patients. RESULTS: In PKD patients, low prehemodialysis and posthemodialysis SBPs were associated with increased mortality, whereas high prehemodialysis DBP was associated with greater survival. Fully adjusted death hazard ratios (and 95% confidence levels) for prehemodialysis and posthemodialysis BP of less than 120 mmHg (reference 140 to <160 mmHg) were 1.30 (1.06-1.92) and 1.45 (1.04-2.02), respectively, and for prehemodialysis DBP of 80 mmHg or more (reference 70 to <80 mmHg) was 0.68 (0.49-0.93, all P values <0.05). Similar associations were observed in non-PKD patients. In pooled analyses, within each commensurate BP stratum, PKD patients exhibited superior survival to non-PKD patients. CONCLUSION: Among hemodialysis patients, those with PKD display a similar BP paradox as those without PKD, even though within each BP category PKD patients maintain superior survival. Randomized clinical trials are needed to define optimal blood pressure targets in the hemodialysis population.

Impact of race on hyperparathyroidism, mineral disarrays, administered vitamin D mimetic, and survival in hemodialysis patients.

Blacks have high rates of chronic kidney disease, are overrepresented among the US dialysis patients, have higher parathyroid hormone levels, but greater survival compared to nonblacks. We hypothesized that mineral and bone disorders (MBDs) have a bearing on survival advantages of black hemodialysis patients. In 139,328 thrice-weekly treated hemodialysis patients, including 32% blacks, in a large dialysis organization, where most laboratory values were measured monthly for up to 60 months (July 2001 to June 2006), we examined differences across races in measures of MBDs and survival predictabilities of these markers and administered the active vitamin D medication paricalcitol. Across each age increment, blacks had higher serum calcium and parathyroid hormone (PTH) levels and almost the same serum phosphorus and alkaline phosphatase levels and were more likely to receive injectable active vitamin D in the dialysis clinic, mostly paricalcitol, at higher doses than nonblacks. Racial differences existed in mortality predictabilities of different ranges of serum calcium, phosphorus, and PTH but not alkaline phosphatase. Blacks who received the highest dose of paricalcitol (>10 µg/week) had a demonstrable survival advantage over nonblacks (case-mix-adjusted death hazard ratio = 0.87, 95% confidence level 0.83-0.91) compared with those who received lower doses (<10 µg/week) or no active vitamin D. Hence, in black hemodialysis patients, hyperparathyroidism and hypercalcemia are more prevalent than in nonblacks, whereas hyperphosphatemia or hyperphosphatasemia are not. Survival advantages of blacks appear restricted to those receiving higher doses of active vitamin D. Examining the effect of MBD modulation on racial survival disparities of hemodialysis patients is warranted.