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.

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.

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.

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.

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.

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.

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.

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.

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.