Background

Peritoneal dialysis (PD) provides outcomes similar to hemodialysis, but its use has decreased in the United States despite its potential for substantial taxpayer savings. We undertook this study to determine the relationship between dialysis unit ownership with PD use and outcomes.

Study design

Observational study.

Setting & participants

All incident dialysis patients (1996 to 2004) from the US Renal Data System.

Predictor

Large dialysis organization (LDO), defined as corporations owning 20 or more freestanding dialysis units located in more than 1 state.

Outcomes & measurements

Odds for an incident dialysis patient undergoing PD and hazards for death on follow-up in incident PD patients for each of the 5 LDOs (non-LDO as reference).

Results

During the 9-year period, 785,531 patients started maintenance dialysis therapy; the proportion receiving care in LDOs increased from 39% to 63%. There were consistent differences in PD use. It was significantly lower in LDO 2 (adjusted odds ratio [OR], 0.66; 95% confidence interval [CI], 0.64 to 0.68), LDO 3 (OR, 0.82; 95% CI, 0.80 to 0.85), and LDO 4 (OR, 0.96; 95% CI, 0.92 to 0.995) and higher in LDO 1 (adjusted OR, 1.06; 95% CI, 1.02 to 1.11) and LDO 5 (adjusted OR, 1.09; 95% CI, 1.06 to 1.12). Between 2000 and 2004, LDO 2 had the least use and greatest risk of death (hazard ratio, 1.08; 95% CI, 1.02 to 1.14); LDO 1 had greater use and the lowest death risk (hazard ratio, 0.87; 95% CI, 0.78 to 0.96).

Limitations

Only cross-sectional associations can be described.

Conclusions

Three of the 5 LDOs had consistently lower PD use. Patients treated in the LDO with the lowest use of PD had the greatest risk of death. Understanding relationships among providers, physicians, and dialysis modality use may help devise strategies for increasing PD use in appropriate patients. This has the potential to reduce the cost of renal replacement therapy and further improve outcomes.

In the United States, chronic peritoneal dialysis take-on has declined among incident ESRD patients. Although increasing age, co-morbidity, and body size may explain part of this decline, other factors likely contribute. Among incident ESRD patients in the United States, we found that peritoneal dialysis take-on significantly decreased from 11% in 1996 to 1997 to 7% in 2002 to 2003 (P < 0.001 for the trend). This decrease remained after adjusting for patient demographics, case-mix, and laboratory data, suggesting the involvement of other factors. This decline in utilization occurred during a time of improving outcomes for incident peritoneal dialysis patients, measured as reduced hazards for death or for the need to transfer to hemodialysis. In contrast, among patients initially treated with hemodialysis, the 12-month adjusted hazards for death or transfer to peritoneal dialysis slightly worsened or were unchanged over this same period. Therefore, the decline in peritoneal dialysis take-on cannot be entirely explained by increasing age, co-morbidity and body size of incident ESRD patients. The decline in utilization has occurred at a time when the early outcomes of CPD patients have improved.

Background

Dietary sodium may influence cognitive function through its effects on cerebrovascular function and cerebral blood flow.

Methods

The aim of this study was to evaluate the association of dietary sodium intake with cognitive decline in community-dwelling older adults. We also evaluated the associations of dietary potassium and sodium:potassium intake with cognitive decline, and associations of these nutrients with micro- and macro-structural brain magnetic resonance imaging (MRI) indices. In all, 1,194 participants in the Health Aging and Body Composition study with measurements of dietary sodium intake (food frequency questionnaire [FFQ]) and change in the modified Mini Mental State Exam (3MS) were included.

Results

The age of participants was 74 ± 3 years with a mean dietary sodium intake of 2,677 ± 1,060 mg/day. During follow-up (6.9 ± 0.1 years), 340 (28%) had a clinically significant decline in 3MS score (≥1.5 SD of mean decline). After adjustment, dietary sodium intake was not associated with odds of cognitive decline (OR 0.96, 95% CI 0.50-1.84 per doubling of sodium). Similarly, potassium was not associated with cognitive decline; however, higher sodium:potassium intake was associated with increased odds of cognitive decline (OR 2.02 [95% CI 1.01-4.03] per unit increase). Neither sodium or potassium alone nor sodium:potassium were associated with micro- or macro-structural brain MRI indices. These results are limited by the use of FFQ.

Conclusions

In community-dwelling older adults, higher sodium:potassium, but not sodium or potassium intake alone, was associated with decline in cognitive function, with no associations observed with micro- and macro-structural brain MRI indices. These findings do not support reduction dietary sodium/increased potassium intake to prevent cognitive decline with aging.

Abstract Background Defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2, chronic kidney disease (CKD) is strongly and independently associated with cardiovascular and overall mortality. We hypothesized that reduced kidney function would be characterized by abnormalities of hemostasis. Methods We tested cross-sectional associations between (eGFR) and multiple hemostatic markers among 6751 participants representing a broad spectrum of kidney function in the Multi-Ethnic Study of Atherosclerosis (MESA). Kidney function was measured using cystatin C (eGFRcys) or creatinine, using CKD Epidemiology Collaboration (eGFRcr). Hemostatic markers included soluble thrombomodulin (sTM), soluble tissue factor (sTF), D-Dimer, von Willebrand factor (vWF), factor VIII, plasmin-antiplasmin complex (PAP), tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1), and fibrinogen. Associations were tested using multivariable linear regression with adjustment for demographics and comorbidities. Results In comparison to persons with eGFRcys >90 ml/min/1.73 m2, subjects with eGFRcys < 60 ml/min/1.73 m2 had adjusted levels of sTM, sTF, D-Dimer, PAP, Factor VIII, TFPI, vWF and fibrinogen that were respectively 86%, 68%, 44%, 22%, 17%, 15%, 12% and 6% higher. Subjects with eGFRcys 60-90 ml/min/1.73 m2 had adjusted levels that were respectively 16%, 14%, 12%, 6%, 6%, 6%, 11% and 4% higher (p < 0.05 for all). Percent differences were not significantly different when groups were categorized by eGFRcr. Conclusions Throughout a broad spectrum of kidney function, lower eGFR was associated with higher levels of hemostatic markers. Dysregulation of hemostasis may be a mechanism by which reduced kidney function promotes higher cardiovascular risk.

BACKGROUND: Chronic kidney disease (CKD) is associated with poor mobility. Peripheral nerve function alterations play a significant role in low mobility. We tested the hypothesis that early CKD is associated with altered sensory, motor and autonomic nerve function. METHODS: Participants in the Health, Aging and Body Composition cohort who had kidney function measures in Year 3 (1999-2000) and nerve function measurements at Year 4 (2000-01) were analyzed (n = 2290). Sensory (vibration threshold, monofilament insensitivity to light and standard touch), motor [compound motor action potentials (CMAPs), nerve conduction velocities (NCVs)] and autonomic (heart rate response and recovery after a 400-m walk test) nerve function as well as participant characteristics were compared across cystatin C- and creatinine-based estimated glomerular filtration rate categorized as ≤60 (CKD) or >60 mL/min/1.73 m2 (non-CKD). The association between CKD and nerve function was examined with logistic regression adjusted for covariates. RESULTS: Participants with CKD (n = 476) were older (77 ± 3 versus 75 ± 3 years; P < 0.05) and had a higher prevalence of diabetes (20.6% versus 13.1%; P < 0.001). CKD was associated with higher odds for vibration detection threshold {odds ratio [OR] 1.7 [95% confidence interval (CI) 1.1-2.7]} and light touch insensitivity [OR 1.4 (95% CI 1.1-1.7)]. CMAPs and NCVs were not significantly different between CKD and non-CKD patients. In adjusted analyses, participants with CKD had higher odds of an abnormal heart rate response [OR 1.6 (95% CI 1.1-2.2)] and poor heart rate recovery [OR 1.5 (95% CI 1.1-2.0)]. CONCLUSIONS: CKD is associated with changes in sensory and autonomic nerve function, even after adjustment for demographics and comorbidities, including diabetes. Longitudinal studies in CKD are needed to determine the contribution of nerve impairments to clinically important outcomes.

Background

Although hypertension contributes to kidney dysfunction in the general population, the contributions of elevated systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP) to kidney function decline in community-dwelling older adults are unknown.

Methods

We used linear and logistic regression to examine the separate and combined associations of SBP, DBP, and PP at baseline with kidney function decline among 4,365 older adults in the Cardiovascular Health Study. We used cystatin C to estimate glomerular filtration rate on 3 occasions over 7 years of follow-up. We defined rapid decline ≥ 3ml/min/year.

Results

Average age was 72.2 and mean (standard deviation) SBP, DBP, and PP were 135 (21), 71 (11), and 65 (18) mm Hg, respectively. SBP and PP, rather than DBP, were most significantly associated with kidney function decline. In adjusted linear models, each 10-mm Hg increment in SBP and PP was associated with 0.13ml/min/year (-0.19, -0.08, P < 0.001) and 0.15-ml/min/year faster decline (-0.21, -0.09, P < 0.001), respectively. Each 10-mm Hg increment in DBP was associated with a nonsignificant 0.10-ml/min/year faster decline (95% confidence interval, -0.20, 0.01). In adjusted logistic models, SBP had the strongest associations with rapid decline, with 14% increased hazard of rapid decline (95% confidence interval, 10% to 17%, P < 0.01) per 10mm Hg. In models combining BP components, only SBP consistently had independent associations with rapid decline.

Conclusions

Our findings suggest that elevated BP, particularly SBP, contributes to declining kidney function in older adults.

Objectives

To examine the association between kidney function and all-cause mortality in octogenarians.

Design

Retrospective analysis of prospectively collected data.

Setting

Community.

Participants

Serum creatinine and cystatin C were measured in 1,053 Cardiovascular Health Study (CHS) All Stars participants.

Measurements

Estimated glomerular filtration rate (eGFR) was determined using the Chronic Kidney Disease Epidemiology Collaboration creatinine (eGFR(CR) ) and cystatin C one-variable (eGFR(CYS) ) equations. The association between quintiles of kidney function and all-cause mortality was analyzed using unadjusted and adjusted Cox proportional hazards models.

Results

Mean age of the participants was 85, 64% were female, 66% had hypertension, 14% had diabetes mellitus, and 39% had prevalent cardiovascular disease. There were 154 deaths over a median follow-up of 2.6 years. The association between eGFR(CR) and all-cause mortality was U-shaped. In comparison with the reference quintile (64-75 mL/min per 1.73 m(2) ), the highest (≥ 75 mL/min per 1.73 m(2) ) and lowest (≤ 43 mL/min per 1.73 m(2) ) quintiles of eGFR(CR) were independently associated with mortality (hazard ratio (HR) = 2.49, 95% confidence interval (CI) = 1.36-4.55; HR = 2.28, 95% CI = 1.26-4.10, respectively). The association between eGFR(CYS) and all-cause mortality was linear in those with eGFR(CYS) of less than 60 mL/min per 1.73 m(2) , and in the multivariate analyses, the lowest quintile of eGFR(CYS) (<52 mL/min per 1.73 m(2) ) was significantly associated with mortality (HR = 2.04, 95% CI = 1.12-3.71) compared with the highest quintile (>0.88 mL/min per 1.73 m(2) ).

Conclusion

Moderate reduction in kidney function is a risk factor for all-cause mortality in octogenarians. The association between eGFR(CR) and all-cause mortality differed from that observed with eGFR(CYS) ; the relationship was U-shaped for eGFR(CR) , whereas the risk was primarily present in the lowest quintile for eGFR(CYS) .

Background

Given the increasing costs and poor outcomes of end-stage renal disease (ESRD), we sought to identify risk factors for ESRD in people with preserved estimated glomerular filtration rate (eGFR), with or without albuminuria, who were at high risk of ESRD.

Methods

This cohort study included participants in the National Kidney Foundation's Kidney Early Evaluation Program (KEEP) with eGFR ≥ 60 mL/min/1.73 m(2) at baseline stratified by the presence or absence of albuminuria. The Chronic Kidney Disease Epidemiology Collaboration equation was used to calculate eGFR. Urine was tested for albuminuria by semiquantitative dipstick. The outcome was the development of treated chronic kidney failure, defined as initiation of maintenance dialysis therapy or kidney transplantation, determined by linkage to the US Renal Data System. We used a Cox model with the Fine-Gray method to assess risk factors for treated chronic kidney failure while accounting for the competing risk of death.

Results

During a median follow-up of 4.8 years, 126 of 13,923 participants with albuminuria (16/10,000 patient-years) and 56 of 109,135 participants without albuminuria (1.1/10,000 patient-years) developed treated chronic kidney failure. Diabetes was a strong risk factor for developing treated chronic kidney failure in participants with and without albuminuria (adjusted HRs of 9.3 [95% CI, 5.7-15.3] and 7.8 [95% CI, 4.1-14.8], respectively). Black race, lower eGFR, and higher systolic blood pressure also were associated with higher adjusted risks of developing treated chronic kidney failure.

Conclusions

In a diverse high-risk cohort of KEEP participants with preserved eGFR, we showed that diabetes, higher systolic blood pressure, lower eGFR, and black race were risk factors for developing treated chronic kidney failure irrespective of albuminuria status, although the absolute risk of kidney failure in participants without albuminuria was very low. Our findings support testing for kidney disease in high-risk populations, which often have otherwise unrecognized kidney disease.

BACKGROUND/OBJECTIVES: Non-steroidal anti-inflammatory drugs (NSAIDs) can cause kidney injury, especially in older adults. However, previously reported associations between NSAID use and kidney health outcomes are inconsistent and limited by reliance on serum creatinine-based GFR estimates. This analysis investigated the association of NSAID use with kidney damage in older adults using multiple kidney health measures. DESIGN: Cross-sectional and longitudinal analyses. SETTING: Multicenter, community-based cohort. PARTICIPANTS: Two thousand nine hundred and ninty nine older adults in the Health ABC Study. A subcohort (n = 500) was randomly selected for additional biomarker measurements. EXPOSURE: Prescription and over-the-counter NSAID use ascertained by self-report. MEASUREMENTS: Baseline estimated glomerular filtration rate (eGFR) by cystatin C (cysC), urine albumin-to-creatinine ratio (ACR), kidney injury molecule-1 (KIM-1), and interleukin-18 (IL-18) were measured in 2,999 participants; alpha-1 microglobulin (α1m), neutrophil gelatinase-associated lipocalin (NGAL), propeptide type III procollagen (PIIINP), and uromodulin (UMOD) were measured in 500 participants. GFR was estimated three times over 10 years and expressed as percent change per year. RESULTS: Participants had a mean age of 74 years, 51% were female, and 41% African-American. No eGFR differences were detected between NSAID users (n = 655) and non-users (n = 2,344) at baseline (72 ml/min/1.73 m2 in both groups). Compared to non-users, NSAID users had lower adjusted odds of having ACR greater than 30 mg/g (0.67; 95% confidence interval (CI) = 0.51-0.89) and lower mean urine IL-18 concentration at baseline (-11%; 95% CI = -4% to -18%), but similar mean KIM-1 (5%; 95% CI = -5% to 14%). No significant differences in baseline concentrations of the remaining urine biomarkers were detected. NSAID users and non-users did not differ significantly in the rate of eGFR decline (-2.2% vs -2.3% per year). CONCLUSION: Self-reported NSAID use was not associated with kidney dysfunction or injury based on multiple measures, raising the possibility of NSAID use without kidney harm in ambulatory older adults. More research is needed to define safe patterns of NSAID consumption.