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BACKGROUND: Obesity is a risk factor for loss of kidney function in the general population, but it is unknown whether it proceeds to affect residual kidney function when patients require dialysis. Our aim was to study the effects of body mass index (BMI) on decline in kidney function and risk to develop anuria after initiation of dialysis therapy. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 1,271 incident dialysis patients from 38 centers in The Netherlands participating in the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD) between 1997 and 2006. PREDICTOR: BMI assessed at 3 months after the initiation of dialysis therapy (baseline) and categorized into 4 groups: less than 20, 20 or greater to 25, 25 or greater to 30, and 30 or greater kg/m(2). OUTCOMES & MEASUREMENTS: The decrease in measured glomerular filtration rate (mGFR) was determined by means of linear mixed models and adjusted for age, sex, primary kidney disease, dialysis modality, smoking, cardiovascular disease, and normalized protein nitrogen appearance and additionally for proteinuria, blood pressure, and baseline mGFR. Cox regression analysis was used to calculate hazard ratios for the development of anuria. RESULTS: Patients had a mean age of 59 +/- 15 years, BMI of 24.8 +/- 4.1 kg/m(2), and mGFR of 4.7 +/- 3.3 mL/min. During 18 months of follow-up, the decrease in mGFR in patients with normal weight was 1.2 mL/min/y (95% confidence interval [CI], 0.7 to 1.6). Compared with those values, adjusted losses of mGFR were 0.4 mL/min/y (95% CI, 0.02 to 0.8) greater for overweight and 1.2 mL/min/y (95% CI, 0.5 to 1.8) greater for obese patients. In contrast, the decrease in underweight patients was 0.6 mL/min/y (-0.1 to 1.3) less. Anuria occurred in 297 patients; the risk was similar among BMI groups after adjustment for confounders and baseline diuresis. LIMITATIONS: Patients with missing BMI or mGFR values at baseline were excluded. CONCLUSION: Obesity is a strong risk factor for the decline in kidney function after initiation of dialysis therapy. Whether obese dialysis patients might benefit from a healthy weight reduction needs to be studied further. Copyright © 2009 National Kidney Foundation, Inc. [ABSTRACT FROM AUTHOR]

The present study explored illness perceptions of end stage renal disease (ESRD) patients on both haemodialysis (HD) and peritoneal dialysis (PD) treatment, and their associations with quality of life. Leventhal's self-regulation model (SRM) was used as a theoretical framework. Illness perceptions and quality of life were assessed with the IPQ-R and the SF-36 in 91 HD and 42 PD patients participating in the NECOSAD-study. Compared to HD patients, PD patients experienced more personal control and had a better understanding of the illness. Illness perceptions explained from 17 to 51% of the variance in quality of life scores. Perception of more symptoms, more consequences and lower personal control were associated with lower well-being. The concept of illness perceptions is useful in understanding the impact of ESRD and of dialysis treatment on quality of life. Interventions aimed at providing more knowledge about ESRD and dialysis, and provision of skills to coping with the illness and its consequences may improve quality of life in dialysis patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Self-rated health (SRH) has been shown to predict mortality in large community-based studies; however, large clinical-based studies of this topic are rare. We assessed whether an SRH item predicts mortality in a large sample of incident dialysis patients beyond sociodemographic, disease, and clinical measures and possible age interaction. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 1,443 predominantly white patients from 38 dialysis centers in The Netherlands participating in the Netherlands Cooperative Study on the Adequacy of Dialysis-2 between 1997 and 2004. PREDICTOR: SRH score completed at 3 months after the start of dialysis therapy (baseline). OUTCOMES & MEASUREMENTS: Cox proportional hazards model estimated the association between SRH and all-cause mortality. Interaction of SRH with age (<65 and >/=65 years) was examined in an additive model. RESULTS: Mean age of patients was 59.6 +/- 14.8 years, with 61% men and 69% married/living together. Mean follow-up was 2.7 +/- 1.8 years. Deaths per SRH group in the multivariate analyses sample: excellent/very good (9 of 63 patients; 14.3%), good (148 of 473 patients; 31.3%), fair (194 of 508 patients; 38.2%), and poor (45 of 71 patients; 63.4%). Patients with poor, fair, or good health ratings had a greater mortality risk than those with excellent/very good health ratings (adjusted hazard ratio [HR(adj)], 3.56; 95% confidence interval [CI], 1.71 to 7.42; HR(adj), 2.09; 95% CI, 1.06 to 4.12; HR(adj), 1.87; 95% CI, 0.95 to 3.70, respectively) independent of a range of risk factors. No age interaction with SRH was found. LIMITATIONS: Although the SRH-mortality association remained strong despite extensive adjustments, unknown residual confounding could still exist. CONCLUSION: SRH is an independent predictor of mortality in incident dialysis patients. Patients with poor SRH in both age strata had a significantly increased risk of mortality even after controlling for demographic and clinical confounders. Patient self-assessment of health can be an invaluable and economical complement to clinical measures in risk assessment. Copyright © 2008 National Kidney Foundation, Inc. [ABSTRACT FROM AUTHOR]

Background: In evaluations of dialysis therapy, an assessment of health-related quality of life (HRQOL) is often important. The aim of this study was to determine the basic psychometric properties, reliability and validity of the short form of the KDQOL i.e. the KDQOL-SF, a dialysis-targeted instrument, and to assess its ability to detect changes over time.Methods: In a prospective cohort study (Netherlands Cooperative Study on the Adequacy of Dialysis, NECOSAD), all new adult ESRD patients in 32 different Dutch centers were consecutively enrolled. Demographic, clinical and HRQOL data were obtained 3 and 12 months after the start of chronic dialysis therapy.Results: The reliability of the KDQOL-SF was supported by test results that were above the recommended minimal values. Validity of KDQOL-SF was confirmed by the hypothesized positive correlations of the overall health rating and renal function, and by the negative correlations between the number of comorbidities and dialysis dose. Moreover, dialysis-targeted dimensions were more sensitive in detecting relevant differences pertaining to kidney diseases than generic dimensions. The KDQOL-SF was able to detect clinical changes over time.Conclusions: The psychometric properties of the KDQOL-SF were good, and the different dialysis-targeted dimensions were informative with a high reliability and validity. These results support the application of the KDQOL-SF in studies evaluating dialysis therapy. [ABSTRACT FROM AUTHOR]

Background: On dialysis, survival among patients with diabetes mellitus is inferior to survival of non-diabetic patients. We hypothesized that patients with diabetes as primary renal disease have worse survival compared to patients with diabetes as a co-morbid condition and aimed to compare all-cause mortality between these patient groups.Methods: Data were collected from the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD), a multicenter, prospective cohort study in which new patients with end stage renal disease (ESRD) were monitored until transplantation or death. Patients with diabetes as primary cause of ESRD were compared with patients with diabetes as co-morbid condition and both of these patient groups were compared to patients without diabetes. Analysis was performed using Kaplan-Meier and Cox regression.Results: Fifteen % of the patients had diabetic nephropathy as primary renal disease (N = 281); 6% had diabetes as co-morbid condition (N = 107) and 79% had no diabetes (N = 1465). During follow-up 42% of patients (N = 787) died. Compared to non-diabetic patients, mortality risk was increased for both patients with diabetes as primary renal disease HR: 1.9 (95% CI 1.6, 2.3) and for patients with diabetes as co-morbid condition HR: 1.7 (95% CI 1.3, 2.2). Mortality was not significantly higher in patients with diabetes as primary renal disease compared to patients with diabetes as co-morbid condition (HR 1.06; 95% CI 0.79, 1.43).Conclusions: This study in patients with ESRD showed no survival difference between patients with diabetes as primary renal disease and patients with diabetes as a co-morbid condition. Both conditions were associated with increased mortality risk compared to non-diabetic patients. [ABSTRACT FROM AUTHOR]

Background. Recent studies showed that mineral meta- bolism disorders are associated with renal function loss in pre-dialysis patients, but their effects in dialysis patients are less well established. We examined associations between parameters of mineral metabolism and loss of residual renal function (RRF) in dialysis patients. Methods. We included 1468 incident haemodialysis (HD) and peritoneal dialysis (PD) patients who were not anuric at dialysis initiation from NECOSAD, a prospective multicentre cohort study. We studied the effects of plasma calcium, phosphorus, calcium–phosphorus product and intact PTH concentrations on loss of RRF. Cox regression models were applied to calculate relative risks of total loss of RRF, defined as anuria during the first 3 years of dialysis. The rate of decline of RRF over time was calculated using general linear mixed models. Results. The mean (SD) age was 59 (15), 62% were men and 59% were treated with HD. We found that both HD and PD patients with the highest phosphorus (P P Conclusion. Disordered mineral metabolism was neither associated with the risk of becoming anuric, nor with the rate of decline in RRF in dialysis patients. Differences in decline were mainly attributable to the baseline rGFR value. [ABSTRACT FROM AUTHOR]

Background. To date, the pathophysiology underlying symptoms in renal patients is still unclear. Symptom management research suggests that identification of related clusters of symptoms could provide insight into underlying determinants associated with multiple symptom experience. Theoretically, symptoms within a cluster could have a synergistic relationship. We aimed to identify symptom clusters in incident dialysis patients, and investigated associations between symptom clusters, clinical variables, functional status as measured by the Karnofsky Index and quality of life. Methods. 1553 haemodialysis (HD) and peritoneal dialysis (PD) patients completed the Kidney Disease Quality of Life Short Form symptom/problem list at 3 months after the start of dialysis. Principal component analysis using varimax rotation was used to identify symptom clusters. Results. Patients were bothered by an average of 2.8 (±2.4) symptoms of ‘moderate bother’ or more. Three clusters were identified, explaining 49% of the total variance. All clusters showed strong negative associations with the SF-36 quality of life dimensions (−0.142 to −0.593) and with functional status (−0.130 to −0.332) in HD and PD patients. In contrast, only the clinical variables serum albumin (−0.084 to −0.232) and haemoglobin (−0.068 to −0.126) were associated with all clusters in HD patients, and Kt/Vurea (−0.089 to −0.125) in PD patients. Conclusions. Symptom clustering does not explain the lack of meaningful associations between symptoms and clinical variables. Strong associations of symptom clusters with quality of life dimensions suggest that psychological factors could better explain symptom burden. Patients’ perceptions of symptoms should be routinely assessed as part of clinical care to improve self-management strategies. [ABSTRACT FROM AUTHOR]

Background. Protein-energy wasting (PEW), inflammation and cardiovascular diseases (CVD) clearly contribute to the high mortality in chronic dialysis. Our aim was to examine the presence of additive interaction between these three risk factors in their association with long-term mortality in dialysis patients. Methods. Patients from a prospective multi-centre cohort study among ESRD patients starting with their first dialysis treatment [the Netherlands Co-operative Study on the Adequacy of Dialysis-2 (NECOSAD-II)] with complete data on these risk factors were included (n = 815, age: 59 ± 15 years, 60% men, 65% HD). Hazard ratios (HR) were calculated for all-cause mortality in 7 years of follow-up. The presence of interaction between the three risk factors was examined, based on additivity of effects. Results. Of all patients, 10% only suffered from PEW (1–5 on the 7-point subjective global assessment), 11% from inflammation (CRP ≥10 mg/L), 14% from CVD and 22% had any combination of two components. Only 6% of the patients had all three risk factors. Patients with either PEW (HR: 1.6, 95% CI: 1.3–2.0), inflammation (1.6, 1.3–2.0) or CVD (1.7, 1.4–2.1) had an increased mortality risk. In patients with all three risk factors, the crude mortality rate of 45/100 person-years was 16 deaths/100 person-years higher than expected from the addition of the solo effects of PEW, inflammation and CVD. The relative excess risk due to interaction was 2.9 (95% CI: 0.3–5.4), implying additive interaction. After adjustment for age, sex, treatment modality, primary kidney diseases, diabetes and malignancy the HR for patients with all three risk factors was 4.8 (95% CI: 3.2–7.2). Conclusions. The concurrent presence of PEW, inflammation and CVD increased the mortality risk strikingly more than expected, implying that PEW interacts with inflammation and CVD in dialysis patients. [ABSTRACT FROM AUTHOR]

Background. The conventional method for C-reactive protein (CRP) measurement is an immunoturbidimetric assay (imCRP, detection limit ≥3 mg/l). However, high-sensitivity CRP (hsCRP, detection limit >0.1 mg/l) has been advocated as preferable biomarker for cardiovascular risk assessment. The aim of this study was to determine agreement between imCRP and hsCRP in end-stage renal disease (ESRD) patients, and to examine whether the association between CRP and mortality is comparable when using imCRP or hsCRP. Methods. Patients from a prospective follow-up study among incident ESRD patients (NECOSAD) with serum CRP available at 3 months of follow-up were included [n = 840, 60% male, mean (SD) age 59 (15) years]. Agreement between imCRP and hsCRP was determined by intraclass correlation coefficient (ICC) and by Cohens kappa (κ) for CRP dichotomized to the presence (CRP >10 mg/l) or absence of systemic inflammation. The association between CRP and mortality was determined by Cox regression analysis and c-statistic. Results. ICC between imCRP and hsCRP was 0.78, which improved to 0.86 after correction for systematic differences between measurement methods. Systemic inflammation was present in 28.2% and absent in 67.6% of patients according to both methods (discordant in 4.2%), resulting in good agreement between the two methods (κ = 0.90). Patients with systemic inflammation had a significantly increased mortality risk compared with patients without systemic inflammation [HRim,adj = 1.49 (95%CI 1.14–1.93) and HRhs,adj = 1.53 (1.18–2.0)]. Predictive capacity of mortality was similar for both CRP methods [c-statisticadj 0.83 (0.79–0.86)]. Conclusion. The agreement between imCRP and hsCRP in patients with ESRD is very good. Furthermore, the association between CRP and mortality in ESRD patients is similar when using imCRP and hsCRP. These data suggest that there is no need to use a high-sensitivity method for the determination of inflammatory status in ESRD patients. [ABSTRACT FROM AUTHOR]

Background. Disturbed mineral metabolism is associated with increased morbidity and mortality, however, its influence on physical symptoms is less clear. We explored the effects of disordered plasma calcium, phosphorus, calcium-phosphorus (Ca × P) product and intact parathyroid hormone (iPTH) concentrations according to the K/DOQI guideline for bone metabolism and disease on the risk of muscle and skin complaints in dialysis patients. Methods. As part of NECOSAD, a prospective multicentre study in the Netherlands, we included 1469 consecutive patients who started haemodialysis or peritoneal dialysis between 1997 and 2004. Muscle pain, cramps and itching (pruritus) and dry (xerosis) skin were repeatedly measured using the Kidney Disease Quality of Life-Short Form questionnaire. Odds ratios (OR) for the risk of complaints over time were calculated by generalized estimating equations (GEE) models. Results. Mean age was 59 ± 15 years, 61% of the patients were male and 63% were on haemodialysis. At baseline >65% of the patients had muscle and skin complaints. Compared with patients who met the target, the risk of muscle pain was increased in patients with hyperphosphataemia [OR: 1.2; 95% confidence interval (CI): 1.1–1.5] iPTH concentrations below the target range were associated with lower risk of cramps (OR 0.8, 95%CI: 0.6–0.9). The risk of pruritus was increased in patients with severely elevated plasma calcium (OR 1.4; 95%CI: 1.1–1.7), phosphorus (OR 1.4; 95%CI: 1.1–1.7) and Ca × P product levels (OR 1.6; 95%CI: 1.3–2.0). Finally, increased plasma calcium concentrations were associated with an elevated risk of xerosis (OR 1.4; 95%CI: 1.1–1.9). Conclusions. Disturbed mineral metabolism according to the K/DOQI guideline is associated with more muscle and skin complaints in dialysis patients. These findings emphasize the importance of keeping mineral metabolism in dialysis patients in tight control. [ABSTRACT FROM AUTHOR]

Quality of life over time in dialysis: The Netherlands Cooperative Study on the Adequacy of Dialysis. Background. Information on the longitudinal quality of life (QL) of patients treated by different dialysis modalities is lacking. Therefore, we performed a prospective cohort study on the QL over time in hemodialysis (HD) and peritoneal dialysis (PD) patients. Methods. New chronic dialysis patients from 13 Dutch dialysis centers were consecutively included. The patients' self-assessment of QL was measured with the SF-36™ form at 3, 6, 12, and 18 months after the start of dialysis treatment. Results. Out of 230 patients who completed the QL questionnaire at least once, 139 patients stayed on their initial dialysis modality, 26 patients switched dialysis modality, 35 patients were transplanted, 28 patients died, and two patients had a recovery of renal function. The QL of patients who died during the study period was considerably worse at baseline and worsened at a faster rate than in the other patient groups. In patients who stayed on their initial dialysis modality, the physical QL decreased over time, whereas the mental QL tended to remain stable. After an adjustment for the initial value of QL and comorbidity, a consistently favorable effect of HD on physical QL over time was found compared with PD, whereas mental QL values remained similar. Parameters of adequacy of dialysis were not associated with QL over time. Conclusion. This prospective cohort study shows that physical QL over time in HD patients is better than in PD patients. [ABSTRACT FROM AUTHOR]