Treatment of rheumatoid arthritis with biologic agents lowers the risk of incident chronic kidney disease

Rheumatoid arthritis is associated with reduced kidney function, possibly due to chronic inflammation or the use of nephrotoxic therapies. However, little is known about the effects of using the newer novel non-nephrotoxic biologic agents on the risk of incident chronic kidney disease (CKD). To study this we used a cohort of 20,757 United States veterans diagnosed with rheumatoid arthritis with an estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73m² or more, recruited between October 2004 and September 2006, and followed through 2013. The associations of biologic use with incident CKD (eGFR under 60 with a decrease of at least 25% from baseline, and eGFR under 45 mL/min/1.73m²) and change in eGFR (<-3, -3 to <0 [reference], and ≥0 mL/min/1.73m²/year) were examined in propensity-matched patients based on their likelihood to initiate biologic treatment, using Cox models and multinomial logistic regression models, respectively. Among 20,757 patients, 4,617 started biologic therapy. In the propensity-matched cohort, patients treated (versus not treated) with biologic agents had a lower risk of incident CKD (hazard ratios 0.95, 95% confidence interval [0.82-1.10] and 0.71 [0.53-0.94] for decrease in eGFR under 60 and under 45 mL/min/1.73m², respectively) and progressive eGFR decline (multinomial odds ratios [95% CI] for eGFR slopes <-3 and ≥0 [versus -3 to <0] mL/min/1.73m²/year, 0.67 [0.58-0.79] and 0.76 [0.69-0.83], respectively). A significant deceleration of eGFR decline was also observed after biologic administration in patients treated with biologics (-1.0 versus -0.4 [mL/min/1.73m²/year] before and after biologic use). Thus, biologic agent administration was independently associated with lower risk of incident CKD and progressive eGFR decline.

Association between vascular access creation and deceleration of estimated glomerular filtration rate decline in late-stage chronic kidney disease patients transitioning to end-stage renal disease

Background

Prior studies have suggested that arteriovenous fistula (AVF) or graft (AVG) creation may be associated with slowing of estimated glomerular filtration rate (eGFR) decline. It is unclear if this is attributable to the physiological benefits of a mature access on systemic circulation versus confounding factors.

Methods

We examined a nationwide cohort of 3026 US veterans with advanced chronic kidney disease (CKD) transitioning to dialysis between 2007 and 2011 who had a pre-dialysis AVF/AVG and had at least three outpatient eGFR measurements both before and after AVF/AVG creation. Slopes of eGFR were estimated using mixed-effects models adjusted for fixed and time-dependent confounders, and compared separately for the pre- and post-AVF/AVG period overall and in patients stratified by AVF/AVG maturation. In all, 3514 patients without AVF/AVG who started dialysis with a catheter served as comparators, using an arbitrary 6-month index date before dialysis initiation to assess change in eGFR slopes.

Results

Of the 3026 patients with AVF/AVG (mean age 67 years, 98% male, 75% diabetic), 71% had a mature AVF/AVG at dialysis initiation. eGFR decline accelerated in the last 6 months prior to dialysis in patients with a catheter (median, from -6.0 to -16.3 mL/min/1.73 m2/year, P < 0.001), while a significant deceleration of eGFR decline was seen after vascular access creation in those with AVF/AVG (median, from -5.6 to -4.1 mL/min/1.73 m2/year, P < 0.001). Findings were independent of AVF/AVG maturation status and were robust in adjusted models.

Conclusions

The creation of pre-dialysis AVF/AVG appears to be associated with eGFR slope deceleration and, consequently, may delay the onset of dialysis initiation in advanced CKD patients.

History of psychosis and mania, and outcomes after kidney transplantation - a retrospective study

History of psychosis or mania, if uncontrolled, both represent relative contraindications for kidney transplantation. We examined 3680 US veterans who underwent kidney transplantation. The diagnosis of history of psychosis/mania was based on a validated algorithm. Measured confounders were used to create a propensity score-matched cohort (n = 442). Associations between pretransplantation psychosis/mania and death with functioning graft, all-cause death, graft loss, and rejection were examined in survival models and logistic regression models. Post-transplant medication nonadherence was assessed using proportion of days covered (PDC) for tacrolimus and mycophenolic acid in both groups. The mean ± SD age of the cohort at baseline was 61 ± 11 years, 92% were male, and 66% and 27% of patients were white and African-American, respectively. Compared to patients without history of psychosis/mania, patients with a history of psychosis/mania had similar risk of death with functioning graft [subhazard ratio (SHR) (95% confidence interval (CI)): 0.94(0.42-2.09)], all-cause death [hazard ratio (95% CI): 1.04 (0.51-2.14)], graft loss [SHR (95% CI): 1.07 (0.45-2.57)], and rejection [odds ratio(95% CI): 1.23(0.60-2.53)]. Moreover, there was no difference in immunosuppressive drug PDC in patients with and without history of psychosis/mania (PDC: 76 ± 21% vs. 78 ± 19%, P = 0.529 for tacrolimus; PDC: 78 ± 17% vs. 79 ± 18%, P = 0.666 for mycophenolic acid). After careful selection, pretransplantation psychosis/mania is not associated with adverse outcomes in kidney transplant recipients.

Radical versus partial nephrectomy, chronic kidney disease progression and mortality in US veterans

Background

Partial nephrectomy is considered the preferred care for localized kidney tumors and may yield better patient and kidney survival and similar oncological outcomes compared with radical nephrectomy. We sought to reexamine these hypotheses in a large nationally representative cohort of US veterans who underwent radical or partial nephrectomy.

Methods

We identified 7073 US veterans who had a partial or radical nephrectomy between 2004 and 2013. We collected data on estimated glomerular filtration rate (eGFR) prior to admission for nephrectomy surgery, immediately after surgery and 180 days postsurgery. We evaluated the association of nephrectomy type and eGFR at different time points with long-term mortality risk in adjusted survival models.

Results

Patients who underwent radical (compared to partial) nephrectomy had a 2-fold greater decline in eGFR (-21.8 ± 17.7 versus -10.3 ± 17.4 mL/min/1.73 m2) immediately after surgery. This larger drop in eGFR resulted in a larger proportion of radical nephrectomy patients having an eGFR <60 mL/min/1.73 m2 at ≥180 days postsurgery. Radical (compared to partial) nephrectomy patients also exhibited a 2.2-fold higher mortality [adjusted death hazard ratio 2.21 (95% confidence interval 1.91-2.55)]. Low eGFRs prior to surgery and 180 days postsurgery were associated with higher risk of postnephrectomy death.

Conclusions

Worse postnephrectomy kidney function and higher mortality were observed with radical nephrectomy, and a low presurgical eGFR and a greater decrease in eGFR postsurgery were associated with worse mortality irrespective of the type of nephrectomy. Additional studies are needed to examine predictors of postnephrectomy outcomes.

Changes in Albuminuria and Subsequent Risk of Incident Kidney Disease

BACKGROUND AND OBJECTIVES

Albuminuria is a robust predictor of CKD progression. However, little is known about the associations of changes in albuminuria with the risk of kidney events outside the settings of clinical trials.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a nationwide cohort of 56,946 United States veterans with an eGFR≥60 ml/min per 1.73 m2, we examined the associations of 1-year fold changes in albuminuria with subsequent incident CKD (>25% decrease in eGFR reaching <60 ml/min per 1.73 m2) and rapid eGFR decline (eGFR slope <-5 ml/min per 1.73 m2 per year) assessed using Cox models and logistic regression, respectively, with adjustment for confounders.

RESULTS

The mean age was 64 (SD, 10) years old; 97% were men, and 91% were diabetic. There was a nearly linear association between 1-year fold changes in albuminuria and incident CKD. The multivariable-adjusted hazard ratios (95% confidence intervals) of incident CKD associated with more than twofold decrease, 1.25- to twofold decrease, 1.25- to twofold increase, and more than twofold increase (versus <1.25-fold decrease to <1.25-fold increase) in albuminuria were 0.82 (95% confidence interval, 0.77 to 0.89), 0.93 (95% confidence interval, 0.86 to 1.00), 1.12 (95% confidence interval, 1.05 to 1.20), and 1.29 (95% confidence interval, 1.21 to 1.38), respectively. Qualitatively similar associations were present for rapid eGFR decline (adjusted odds ratios; 95% confidence intervals for corresponding albuminuria changes: adjusted odds ratio, 0.86; 95% confidence interval, 0.78 to 0.94; adjusted odds ratio, 0.98; 95% confidence interval, 0.89 to 1.07; adjusted odds ratio, 1.18; 95% confidence interval, 1.08 to 1.29; and adjusted odds ratio, 1.67; 95% confidence interval, 1.54 and 1.81, respectively).

CONCLUSIONS

Relative changes in albuminuria over a 1-year interval were linearly associated with subsequent risk of kidney outcomes. Additional studies are warranted to elucidate the underlying mechanisms of the observed associations and test whether active interventions to lower elevated albuminuria can improve kidney outcomes.

Pre-End-Stage Renal Disease Hemoglobin Variability Predicts Post-End-Stage Renal Disease Mortality in Patients Transitioning to Dialysis

BACKGROUND

Hemoglobin variability (Hb-var) has been associated with increased mortality both in non-dialysis dependent chronic kidney disease (NDD-CKD) and end-stage renal disease (ESRD) patients. However, the impact of Hb-var in advanced NDD-CKD on outcomes after dialysis initiation remains unknown.

METHODS

Among 11,872 US veterans with advanced NDD-CKD transitioning to dialysis between October 2007 through September 2011, we assessed Hb-var calculated from the residual SD of at least 3 Hb values during the last 6 months before dialysis initiation (prelude period) using within-subject linear regression models, and stratified into quartiles. Outcomes included post-transition all-cause, cardiovascular, and infection-related mortality, assessed in Cox proportional hazards models and adjusted for demographics, comorbidities, length of hospitalization, medications, estimated glomerular filtration rate (eGFR), type of vascular access, Hb parameters (baseline Hb [i.e., intercept] and change in Hb [i.e., slope]), and number of Hb measurements.

RESULTS

Higher prelude Hb-var was associated with use of iron and antiplatelet agents, tunneled dialysis catheter use, higher levels of baseline Hb, change in Hb, eGFR, and serum ferritin. After multivariable adjustment, higher prelude Hb-var was associated with higher post-ESRD all-cause and infection-related mortality, but not cardiovascular mortality (adjusted hazard ratios [95% CI] for the highest [vs. lowest] quartile of Hb-var, 1.10 [1.02-1.19], 1.28 [0.93-1.75], and 0.93 [0.79-1.10], respectively).

CONCLUSIONS

High pre-ESRD Hb-var is associated with higher mortality, particularly from infectious causes rather than cardiovascular causes. Further research is required to clarify the underlying mechanisms and true causal nature of the observed association.

Association of Restless Legs Syndrome With Incident Parkinson's Disease

Study Objectives

The association between restless legs syndrome (RLS) and Parkinson's disease (PD) has been extensively studied with inconclusive results; therefore, we prospectively examined the associations of the presence of RLS with development of incident PD.

Methods

From a nationally representative prospective cohort of almost 3.5 million US veterans (age: 60 ± 14 years, 93% male, median follow-up time of 7.8 years [interquartile range: 6.4-8.4 years]), we created a propensity-matched cohort of 100882 PD-free patients and examined the association between prevalent RLS and incident PD. This association was also assessed in the entire cohort. Associations were examined using Cox models.

Results

There were 68 incident PD events (0.13%, incidence rate 1.87 [1.48-2.37]/10000 patient-years) in the RLS-negative group, and 185 incident PD events (0.37%, incidence rate 4.72 [4.09-5.45]/10000 patient-years) in the RLS-positive group in the propensity-matched cohort. Prevalent RLS was associated with more than twofold higher risk of incident PD (hazard ratio [HR]: 2.57, 95% confidence interval [CI]: 1.95-3.39) compared to RLS-negative patients. Qualitatively similar results were found when we examined the entire 3.5 million cohort: Prevalent RLS was associated with more than twofold higher risk of incident PD (multivariable adjusted HR: 2.81, 95%CI: 2.41-3.27).

Conclusion

RLS and PD share common risk factors. In this large cohort of US veterans, we found that prevalent RLS is associated with higher risk of incident PD during 8 years of follow-up, suggesting that RLS could be an early clinical feature of incident PD.

Association of serum albumin level and venous thromboembolic events in a large cohort of patients with nephrotic syndrome

Background

Prior small studies have suggested an association between low serum albumin and increased risk of venous thromboembolic (VTE) events in patients with nephrotic syndrome (NS).

Methods

From a nationally representative prospective cohort of over 3 million US veterans with baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m 2 , we identified 7037 patients with NS based on ICD-9 codes. Association between serum albumin and risk of incident VTE was assessed using Cox regression analysis with adjustments for age, gender, race, comorbidities, eGFR, body mass index and anticoagulant treatment.

Results

Mean age was 57 ± 11 years, patients were 96% male, 32% African-American and 60% diabetic. There were a total of 158 VTE events over a median follow-up of 8.1 years; 16 events [absolute event rate (AER) 4.1%, event rate 8.5/1000 patient-years (PY)] in patients with albumin <2.5 g/dL, 18 events (AER 3.4%, event rate 5.7/1000 patient-years) in patients with albumin 2.5-2.99 g/dL, 89 events (AER 2.5%, event rate 3.4/1000 patient-years) in patients with albumin 3-3.99 g/dL and 35 events (AER 1.4%, event rate 1.9/1000 patient-years) in patients with albumin ≥4 g/dL. Compared with patients with albumin ≥4 g/dL, those with albumin levels of 3-3.99 g/dL [adjusted hazard ratio (HR): 1.51, 95% confidence interval (CI): 1.01-2.26], 2.5-2.99 g/dL (HR: 2.24, 95% CI: 1.24-4.05) and <2.5 g/dL (HR: 2.79, 95% CI: 1.45-5.37) experienced a linearly higher risk of VTE events.

Conclusions

Lower serum albumin is a strong independent predictor for VTE events in NS. The risk increases proportionately with declining albumin levels. Clinical trials are needed to determine benefit of prophylactic anticoagulation in NS patients with moderately lower serum albumin levels.

Pre-ESRD Depression and Post-ESRD Mortality in Patients with Advanced CKD Transitioning to Dialysis

BACKGROUND AND OBJECTIVES

Depression in patients with nondialysis-dependent CKD is often undiagnosed, empirically overlooked, and associated with higher risk of death, progression to ESRD, and hospitalization. However, there is a paucity of evidence on the association between the presence of depression in patients with advanced nondialysis-dependent CKD and post-ESRD mortality, particularly among those in the transition period from late-stage nondialysis-dependent CKD to maintenance dialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

From a nation-wide cohort of 45,076 United States veterans who transitioned to ESRD over 4 contemporary years (November of 2007 to September of 2011), we identified 10,454 (23%) patients with a depression diagnosis during the predialysis period. We examined the association of pre-ESRD depression with all-cause mortality after transition to dialysis using Cox proportional hazards models adjusted for sociodemographics, comorbidities, and medications.

RESULTS

Patients were 72±11 years old (mean±SD) and included 95% men, 66% patients with diabetes, and 23% blacks. The crude mortality rate was similar in patients with depression (289/1000 patient-years; 95% confidence interval, 282 to 297) versus patients without depression (286/1000 patient-years; 95% confidence interval, 282 to 290). Compared with patients without depression, patients with depression had a 6% higher all-cause mortality risk in the adjusted model (hazard ratio, 1.06; 95% confidence interval, 1.03 to 1.09). Similar results were found across all selected subgroups as well as in sensitivity analyses using alternate definitions of depression.

CONCLUSION

Pre-ESRD depression has a weak association with post-ESRD mortality in veterans transitioning to dialysis.

Association of symptoms of insomnia and sleep parameters among kidney transplant recipients

OBJECTIVE

Insomnia complaints are frequent among kidney transplant (kTx) recipients and are associated with fatigue, depression, lower quality of life and increased morbidity. However, it is not known if subjective insomnia symptoms are associated with objective parameters of sleep architecture. Thus, we analyze the association between sleep macrostructure and EEG activity versus insomnia symptoms among kTx recipients.

METHODS

Participants (n₁=100) were selected from prevalent adult transplant recipients (n₀=1214) followed at a single institution. Insomnia symptoms were assessed by the Athens Insomnia Scale (AIS) and standard overnight polysomnography was performed. In a subgroup of patients (n₂=56) sleep microstructure was also analyzed with power spectral analysis.

RESULTS

In univariable analysis AIS score was not associated with sleep macrostructure parameters (sleep latency, total sleep time, slow wave sleep, wake after sleep onset), nor with NREM and REM beta or delta activity in sleep microstructure. In multivariable analysis after controlling for covariables AIS score was independently associated with the proportion of slow wave sleep (β=0.263; CI: 0.026-0.500) and REM beta activity (β=0.323; CI=0.041-0.606) (p<0.05 for both associations).

CONCLUSIONS

Among kTx recipients the severity of insomnia symptoms is independently associated with higher proportion of slow wave sleep and increased beta activity during REM sleep but not with other parameters sleep architecture. The results suggest a potential compensatory sleep protective mechanism and a sign of REM sleep instability associated with insomnia symptoms among this population.

Blood Pressure Before Initiation of Maintenance Dialysis and Subsequent Mortality

BACKGROUND

Mortality is extremely high immediately after the transition to dialysis therapy, but the association of blood pressure (BP) before dialysis therapy initiation with mortality after dialysis therapy initiation remains unknown.

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

17,729 US veterans transitioning to dialysis therapy in October 2007 to September 2011, with a median follow-up of 2.0 years.

PREDICTOR

Systolic (SBP) and diastolic BP (DBP) averaged over the last 1-year predialysis transition period as 6 (<120 to ≥160mmHg in 10-mmHg increments) and 5 (<60 to ≥90mmHg in 10-mmHg increments) categories, respectively, and as continuous measures.

OUTCOMES & MEASUREMENTS

Postdialysis all-cause mortality, assessed over different follow-up periods (ie, <3, 3-<6, 6-<12, and ≥12 months after dialysis therapy initiation) using Cox regressions adjusted for demographics, comorbid conditions, medications, cardiovascular medication adherence, body mass index, estimated glomerular filtration rate, and type of vascular access.

RESULTS

Mean predialysis SBP and DBP were 141.2±16.1 (SD) and 73.7±10.6mmHg, respectively. There was a reverse J-shaped association of SBP with all-cause mortality, with significantly higher mortality seen with SBP<140mmHg. Mortality risks associated with lower SBP were greatest in the first 3 months after dialysis therapy initiation, with multivariable-adjusted HRs of 2.40 (95% CI, 1.96-2.93), 1.99 (95% CI, 1.66-2.40), 1.35 (95% CI, 1.13-1.62), 0.98 (95% CI, 0.78-1.22), and 0.76 (95% CI, 0.57-1.00) for SBP <120, 120 to <130, 130 to <140, 150 to <160, and ≥160 (vs 140-<150) mmHg, respectively. No consistent association was observed between predialysis DBP and postdialysis mortality.

LIMITATIONS

Results cannot be inferred to show causality and may not be generalizable to women or the general US population.

CONCLUSIONS

Lower predialysis SBP is associated with higher all-cause mortality in the immediate postdialysis period. Predialysis DBP showed no consistent association with postdialysis mortality. Further studies are needed to clarify ideal predialysis SBP levels among incident dialysis patients as a potential means to improve the excessively high early dialysis mortality.

Association of Glycemic Status During Progression of Chronic Kidney Disease With Early Dialysis Mortality in Patients With Diabetes

OBJECTIVE

Although early trials suggested that intensive glycemic targets reduce the number of complications with diabetes, contemporary trials indicate no cardiovascular benefit and potentially higher mortality risk. As patients with advanced chronic kidney disease (CKD) transitioning to treatment with dialysis were excluded from these studies, the optimal glycemic level in this population remains uncertain. We hypothesized that glycemic status, defined by hemoglobin A_1c (HbA--_1c) and random glucose levels, in the pre-end-stage renal disease (ESRD) period is associated with higher 1-year post-ESRD mortality among patients with incident diabetes who have ESRD.

RESEARCH DESIGN AND METHODS

Among 17,819 U.S. veterans with diabetic CKD transitioning to dialysis from October 2007 to September 2011, we examined the association of mean HbA--_1c and random glucose levels averaged over the 1-year pre-ESRD transition period with mortality in the first year after dialysis initiation. All-cause mortality hazard ratios (HRs) were estimated using multivariable survival models. Secondary analyses examined cardiovascular mortality using competing risks methods.

RESULTS

HbA--_1c levels ≥8% (≥64 mmol/mol) were associated with higher mortality in the first year after dialysis initiation (reference value 6% to <7% [42-53 mmol/mol]): adjusted HRs [aHRs] 1.19 [95% CI 1.07-1.32] and 1.48 (1.31-1.67) for HbA--_1c 8% to <9% [64-75 mmol/mol] and ≥9% [≥75 mmol/mol], respectively). Random glucose levels ≥200 mg/dL were associated with higher mortality (reference value 100 to <125 mg/dL): aHR 1.34 [95% CI 1.20-1.49]). Cumulative incidence curves showed that incrementally higher mean HbA--_1c and random glucose levels were associated with increasingly higher cardiovascular mortality.

CONCLUSIONS

In patients with diabetes and CKD transitioning to dialysis, higher mean HbA--_1c and random glucose levels during the pre-ESRD prelude period were associated with higher 1-year post-ESRD mortality. Clinical trials are warranted to examine whether modulating glycemic status improves survival in this population.

Heart Failure Increases the Risk of Adverse Renal Outcomes in Patients With Normal Kidney Function

BACKGROUND

Heart failure (HF) is associated with poor cardiac outcomes and mortality. It is not known whether HF leads to poor renal outcomes in patients with normal kidney function. We hypothesized that HF is associated with worse long-term renal outcomes.

METHODS AND RESULTS

Among 3 570 865 US veterans with estimated glomerular filtration rate (eGFR) ≥60 mL min-1 1.73 m-2 during October 1, 2004 to September 30, 2006, we identified 156 743 with an International Classification of Diseases, Ninth Revision, diagnosis of HF. We examined the association of HF with incident chronic kidney disease (CKD), the composite of incident CKD or mortality, and rapid rate of eGFR decline (slopes steeper than -5 mL min-1 1.73 m-2 y-1) using Cox proportional hazard analyses and logistic regression. Adjustments were made for various confounders. The mean±standard deviation baseline age and eGFR of HF patients were 68±11 years and 78±14 mL min-1 1.73 m-2 and in patients without HF were 59±14 years and 84±16 mL min-1 1.73 m-2, respectively. HF patients had higher prevalence of hypertension, diabetes mellitus, cardiac, peripheral vascular and chronic lung diseases, stroke, and dementia. Incidence of CKD was 69.0/1000 patient-years in HF patients versus 14.5/1000 patient-years in patients without HF, and 22% of patients with HF had rapid decline in eGFR compared with 8.5% in patients without HF. HF patients had a 2.12-, 2.06-, and 2.13-fold higher multivariable-adjusted risk of incident CKD, composite of CKD or mortality, and rapid eGFR decline, respectively.

CONCLUSIONS

HF is associated with significantly higher risk of incident CKD, incident CKD or mortality, and rapid eGFR decline. Early diagnosis and management of HF could help reduce the risk of long-term renal complications.

Do we really need more evidence to use hepatitis C positive donor kidney more liberally?

The number of patients listed active for kidney transplantation has continued to rise over the last 10 years, leading to significantly increased wait-list time for patients awaiting kidney transplantation in the USA. This increased demand has led to a supply–demand mismatch and should prompt clinicians to seek timely solutions to improve access to available organs. Hepatitis C virus positive [HCV(+)] kidneys continue to be discarded without clear evidence that they lead to poor outcomes in the current era of highly efficacious HCV treatment with direct-acting antiviral agents (DAAs). Increased utilization of HCV(+) donor kidneys will decrease wait-list time and improve availability of donor organs. Emerging data suggests that HCV can be successfully treated with DAAs after kidney transplantation with 100% sustained virologic response rates and no significant changes from baseline kidney function. Utilization of HCV(+) donor kidneys should be considered more liberally in the era of highly effective HCV treatment. Further studies are warranted to assess the long-term effect of HCV(+) donor kidneys in transplant recipients in the new era of DAAs.

Association of Systolic Blood Pressure Variability With Mortality, Coronary Heart Disease, Stroke, and Renal Disease

BACKGROUND

Intraindividual blood pressure (BP) fluctuates dynamically over time. Previous studies suggested an adverse link between greater visit-to-visit variability in systolic blood pressure (SBP) and various outcomes. However, these studies have significant limitations, such as a small size, inclusion of selected populations, and restricted outcomes.

OBJECTIVES

This study investigated the association of increased visit-to-visit variability and all-cause mortality, cardiovascular events, and end-stage renal disease (ESRD) in a large cohort of U.S. veterans.

METHODS

From among 3,285,684 U.S. veterans with and without hypertension and normal estimated glomerular filtration rates (eGFR) during 2005 and 2006, we identified 2,865,157 patients who had 8 or more outpatient BP measurements. Systolic blood pressure variability (SBPV) was measured using the SD of all SBP values (normally distributed) in 1 individual. Associations of SD quartiles (<10.3, 10.3 to 12.7, 12.7 to 15.6, and ≥15.6 mm Hg) with all-cause mortality, incident coronary heart disease (CHD), stroke, and ESRD was examined using Cox models adjusted for sociodemographic characteristics, baseline eGFR, comorbidities, body mass index, SBP, diastolic BP, and antihypertensive medication use.

RESULTS

Several sociodemographic variables (older age, male sex, African-American race, divorced or widowed status) and clinical characteristics (lower baseline eGFR, higher SBP and diastolic BP), and comorbidities (presence of diabetes, hypertension, cardiovascular disease, and lung disease) were all associated with higher intraindividual SBPV. The multivariable adjusted hazard ratios and 95% confidence intervals for SD quartiles 2 through 4 (compared with the first quartile) associated with all-cause mortality, CHD, stroke, and ESRD were incrementally higher.

CONCLUSIONS

Higher SBPV in individuals with and without hypertension was associated with increased risks of all-cause mortality, CHD, stroke, and ESRD. Further studies are needed to determine interventions that can lower SBPV and their impact on adverse health outcomes.

Effect of Age on the Association of Vascular Access Type with Mortality in a Cohort of Incident End-Stage Renal Disease Patients

BACKGROUND/AIMS

All hemodialysis (HD) patients are generally recommended to create a fistula first; but to create a mature arteriovenous fistula (AVF) can be challenging in elderly individuals. It is unclear if elderly incident HD patients derive a survival benefit from an AVF over an arteriovenous graft (AVG) or a tunneled central venous catheter (TDC).

METHODS

We examined the association of vascular access type (AVF, AVG, and TDC with and without a maturing AVF/AVG at dialysis transition) at HD initiation with all-cause, cardiovascular (CV), and infection-related mortality in 46,786 US veterans using Cox models with adjustment for confounders. Effect modification by age was examined by examining associations in pre-specified age subgroups (<60, 60-<70, 70-<80, and ≥80 years old), and by including interaction terms.

RESULTS

Patients numbering 8,940 (19%) started HD with an AVF, 1,090 (3%) with an AVG, 8,262 (18%) with a TDC and a maturing AVF/AVG and 28,494 (61%) with a TDC without a maturing AVF/AVG. A total of 13,303 all-cause, 4,392 CV, and 1,058 infection-related deaths were observed in the first year after HD transition. Compared to patients with AVF, those with AVG and TDC with and without maturing AVF/AVG had incrementally higher overall risk of all-cause mortality and CV mortality. Only TDC use was associated with higher infection-associated mortality. These associations were not modified by age.

CONCLUSION

Although most of our patients consisted of male veterans and the results may not be generalized to the general population, the use of TDCs is associated with poor outcomes even in the most elderly incident HD patients.

Early Mortality Associated with Inpatient versus Outpatient Hemodialysis Initiation in a Large Cohort of US Veterans with Incident End-Stage Renal Disease

BACKGROUND

Mortality in the immediate post-hemodialysis transition period is extremely high. Many end-stage renal disease (ESRD) patients in the US start dialysis in an inpatient setting, but the characteristics of patients starting dialysis as inpatients, and the association of inpatient hemodialysis transition with mortality remain unclear.

METHODS

We examined 48,261 US veterans who transitioned to hemodialysis between October 2007 and September 2011. Associations of inpatient hemodialysis starting with all-cause mortality were examined in Cox proportional hazard models, with adjustments for demographics, comorbidities, vascular access type, pre-dialysis nephrology care and medication use, and last pre-ESRD estimated glomerular filtration rate and hemoglobin.

RESULTS

A total of 22,338 (46.3%) patients received the first hemodialysis treatment in an inpatient setting. Inpatient hemodialysis transition was associated with older age, presence of a tunneled catheter, higher comorbidity burden, and lack of pre-dialysis nephrology care. A total of 8,674 patients died (mortality rate 405/1,000 patient-years, 95% CI 397-413) during the first 6 months after transition to hemodialysis. The starting of inpatient vs. outpatient hemodialysis was associated with significantly higher crude all-cause mortality, but this association was attenuated after multivariable adjustments.

CONCLUSIONS

Transition to hemodialysis in an inpatient setting is more common in older and sicker individuals, and in patients without pre-dialysis nephrology care and those who used a catheter for vascular access. Future studies are needed to determine if a higher proportion of patients could start hemodialysis treatment in outpatient clinics, through interventions targeting modifiable risk factors such as timely vascular access placement or earlier nephrology referrals.

Depressive Symptoms Are Associated With Objectively Measured Sleep Parameters in Kidney Transplant Recipients

STUDY OBJECTIVES

Both depression and sleep complaints are very prevalent among kidney transplant (kTx) recipients. However, details of the complex relationship between sleep and depression in this population are not well documented. Thus, we investigated the association between depressive symptoms and sleep macrostructure parameters among prevalent kTx recipients.

METHODS

Ninety-five kTx recipients participated in the study (54 males, mean ± standard devation age 51 ± 13 years, body mass index 26 ± 4 kg/m2, estimated glomerular filtration rate 53 ± 19 ml/min/1.73 m2). Symptoms of depression were assessed by the Center for Epidemiologic Studies - Depression Scale (CES-D). After 1-night polysomnography each recording was visually scored and sleep macrostructure was analyzed.

RESULTS

The CES-D score was significantly associated with the amount of stage 2 sleep (r = 0.20, P < .05), rapid eye movement (REM) latency (r = 0.21, P < .05) and REM percentage (r = -0.24, P < .05), but not with the amount of slow wave sleep (r = -0.12, P > .05). In multivariable linear regression models the CES-D score was independently associated with the amount of stage 2 sleep (β: 0.205; confidence interval: 0.001-0.409; P = .05) and REM latency (β: 0.234; confidence interval: 0.001-0.468; P = .05) after adjustment for potential confounders.

CONCLUSIONS

Depressive symptoms among kTx recipients are associated with increased amount of stage 2 sleep and prolonged REM latency. Further studies are needed to confirm our findings and understand potential clinical implications.

Transition of care from pre-dialysis prelude to renal replacement therapy: the blueprints of emerging research in advanced chronic kidney disease

In patients with advanced (estimated glomerular filtration rate <25 mL/min/1.73 m2) non-dialysis-dependent chronic kidney disease (CKD) the optimal transition of care to renal replacement therapy (RRT), i.e. dialysis or transplantation, is not known. Mortality and hospitalization risk are extremely high upon transition and in the first months following the transition to dialysis. Major knowledge gaps persist pertaining to differential or individualized transitions across different demographics and clinical measures during the 'prelude' period prior to the transition, particularly in several key areas: (i) the best timing for RRT transition; (ii) the optimal RRT type (dialysis versus transplant), and in the case of dialysis, the best modality (hemodialysis versus peritoneal dialysis), format (in-center versus home), frequency (infrequent versus thrice-weekly versus more frequent) and vascular access preparation; (iii) the post-RRT impact of pre-RRT prelude conditions and events such as blood pressure and glycemic control, acute kidney injury episodes, and management of CKD-specific conditions such as anemia and mineral disorders; and (iv) the impact of the above prelude conditions on end-of-life care and RRT decision-making versus conservative management of CKD. Given the enormous changes occurring in the global CKD healthcare landscape, as well as the high costs of transitioning to dialysis therapy with persistently poor outcomes, there is an urgent need to answer these important questions. This review describes the key concepts and questions related to the emerging field of 'Transition of Care in CKD', systematically defines six main categories of CKD transition, and reviews approaches to data linkage and novel prelude analyses along with clinical applications of these studies.

Race, Serum Potassium, and Associations With ESRD and Mortality

BACKGROUND

Recent studies suggest that potassium levels may differ by race. The basis for these differences and whether associations between potassium levels and adverse outcomes differ by race are unknown.

STUDY DESIGN

Observational study.

SETTING & PARTICIPANTS

Associations between race and potassium level and the interaction of race and potassium level with outcomes were investigated in the Racial and Cardiovascular Risk Anomalies in Chronic Kidney Disease (RCAV) Study, a cohort of US veterans (N=2,662,462). Associations between African ancestry and potassium level were investigated in African Americans in the Atherosclerosis Risk in Communities (ARIC) Study (N=3,450).

PREDICTORS

Race (African American vs non-African American and percent African ancestry) for cross-sectional analysis; serum potassium level for longitudinal analysis.

OUTCOMES

Potassium level for cross-sectional analysis; mortality and end-stage renal disease for longitudinal analysis.

RESULTS

The RCAV cohort was 18% African American (N=470,985). Potassium levels on average were 0.162mmol/L lower in African Americans compared with non-African Americans, with differences persisting after adjustment for demographics, comorbid conditions, and potassium-altering medication use. In the ARIC Study, higher African ancestry was related to lower potassium levels (-0.027mmol/L per each 10% African ancestry). In both race groups, higher and lower potassium levels were associated with mortality. Compared to potassium level of 4.2mmol/L, mortality risk associated with lower potassium levels was lower in African Americans versus non-African Americans, whereas mortality risk associated with higher levels was slightly greater. Risk relationships between potassium and end-stage renal disease were weaker, with no difference by race.

LIMITATIONS

No data for potassium intake.

CONCLUSIONS

African Americans had slightly lower serum potassium levels than non-African Americans. Consistent associations between potassium levels and percent African ancestry may suggest a genetic component to these differences. Higher and lower serum potassium levels were associated with mortality in both racial groups.

Pre-ESRD Dementia and Post-ESRD Mortality in a Large Cohort of Incident Dialysis Patients

BACKGROUND

Conservative management may be a desirable option for elderly, fragile, or demented patients who reach end-stage renal disease (ESRD), yet some patients with dementia are placed on renal replacement therapy nonetheless.

METHODS

From a nationwide cohort of 45,076 US veterans who transitioned to ESRD over 4 contemporary years (October 1, 2007 to September 30, 2011), we identified 1,336 (3.0%) patients with International Classification of Diseases, Ninth Revision, Clinical Modification code-based dementia diagnosis during the prelude (predialysis) period. We examined the association of prelude dementia with all-cause mortality within the first 6 months following transition to dialysis, using a propensity-matched cohort and Cox proportional hazards models.

RESULTS

In the entire cohort, the overall mean ± standard deviation age at baseline was 72 ± 11 years, 95% were male, 23% were African-American, and 66% were diabetic. There were 8,080 (18.5%) deaths (mortality rate, 412; 95% confidence interval [CI], 403-421/1,000 patient-years) in the dementia-negative group, and 396 (29.6%) deaths (mortality rate, 708; 95% CI, 642-782/1,000 patient-years) in the dementia-positive group in the entire cohort in the first 6 months after dialysis initiation. Presence of dementia was associated with higher risk of all-cause mortality (adjusted hazard ratio, 1.25; 95% CI, 1.12-1.38) compared to dementia-free patients in the first 6 months after dialysis initiation.

CONCLUSION

Pre-ESRD dementia is associated with increased risk of early post-ESRD mortality in veterans transitioning to dialysis.