Prognostic Determinants of Survival and Quality of Life in Prevalent End-stage Kidney Disease Patients

Study Overview
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Brief Summary
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Patients with end-stage kidney disease are treated with dialysis to increase their life expectancy as well as their quality of life (QoL). Scientific researchers are currently still looking for markers to evaluate dialysis in an objective way. It has been proven before that the currently clinically used parameters (like the dialysis adequacy parameter Kt/V) are not appropriate enough to estimate dialysis dose. The current project aims at identifying potential (predicting) biomarkers based on functional capacity, nutritional status and/or QoL.

Detailed Description
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This multisite study is an observational study during which prevalent dialysis patients are followed during maximum 3 years, and they undergo different tests. Once a year (max 3 times), blood is sampled, stool is collected, and finger nails are taken all before a midweek session. Demographic data are registered and Davies-Stokes scores are calculated. Blood is analysed for different solutes: e.g. total and free fractions of protein-bound toxins, sedimentation, erythrocytes, hematocrit, leukocytes, thrombocytes, Ferritin, VitB12, Fasting glucose, c-reactive protein, urea, creatinine, albumin, total protein, cholesterol, triglycerides, bilirubin,... At the same occasion, patients are questioned about different items (QoL, nutrition) by a (study) nurse or coordinator, using different questionnaires: Euroqol 5 dimension scale (EQ-5D), Patient-Reported Outcomes Measurement Information System (Promis-29), and Mini Nutritional Assessment (MNA). A subgroup of patients were asked to perform some functional tests: Tinetti-Test, Sit to Stand (5 times), Frailty and Injuries: Cooperative Studies on Intervention Techniques (Ficsit) test, 2 or 6 minutes walking test, handgrip strength and quadriceps power measurement, back scratch test, compensatory stepping correction-backward test and skin fold measurement. All tests are non-invasive and are validated for routine measurements in the elderly. In order to quantify sleep, patients were asked to wear a Motionwatch (Actigraphy) to register their arm movements during 2 or 3 nights as well as to fill out 2 questionnaires related to sleep: Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI). To compare sleep in dialysis patients with healthy persons, age and gender matched healthy volunteers were also included in the study and were asked to sleep 2 or 3 nights with the Motionwatch and to complete the ISI and PSQI. Patients who were transplanted got an extra blood sampling just before transplantation as well as 4 months after transplantation.

Official Title
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Prognostic Determinants (Nutritional Versus Functional Versus Biochemical) of Survival and Quality of Life in Prevalent End-stage Kidney Disease Patients Treated With Dialysis

Conditions
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Dialysis, Quality of Life, Nutrition

Intervention / Treatment
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* Other: Blood sampling
* Other: Nails collection
* Other: Stool collection
* Other: Physical Functioning
* Other: Sleep


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - end-stage kidney disease patients treated with dialysis (peritoneal dialysis or hemodialysis) Exclusion Criteria: active inflammation malignancy cognitive disorder not understanding the dutch language

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Blood sampling|Blood is sampled before a midweek dialysis session once every year with a maximum of 3 samples in total.|
|Other: Nails collection|At the occasion of the blood sampling, finger nails are cut and collected.|
|Other: Stool collection|At the occasion of the blood sampling, patients are asked to bring a stool sample.|
|Other: Physical Functioning|A subgroup of patients are asked to perform some physical tests.|
|Other: Sleep|A subgroup of patients are asked to sleep 2-3 nights with a Motionwatch (Actigraphy) to recording their arm movements.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between protein-bound uremic toxin concentrations and physical parameter 6 minute walking test (6MWT) | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. As physical parameters, the 6MWT (m) is performed. | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and physical parameter sit-to-stand test | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. As physical parameters, the sit-to-stand test is performed (sec). | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and muscle strength | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. Muscles strength is measured with handgrip test (N) and quadriceps test (N). | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and risk of fall | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. An adaptation of the Dialysis Fall Risk Index is used as parameter for risk of fall (maximum score 12 - higher risk for higher score). | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and nutritional status | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. Nutritional status is scored using the Mini Nutritional Assessment (MNA) questionnaire (score 24-30: normal nutritional status; 17-23.5: risk for malnutrition; 0-17: malnutrition) | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and quality of life (EQ-5D) | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. Quality of life (QoL) is scored using the EQ-5D questionnaire (score 5-15 - lower QoL for higher score). | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and quality of life (Promis) | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. Quality of life (QoL) is scored using the Promis questionnaire (standard deviation score - 40-60: normal score). | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and objective sleep parameter (sleep efficiency) | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. The objective parameter 'sleep efficiency' (%) is derived from actigraphy measurement (better sleep for higher %). | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and objective sleep parameter (fragmentation index) | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. The objective parameter 'fragmentation index' (higher score is worse) is derived from actigraphy measurement. | 10/2015 - 12/2018 | 
| Correlation between protein-bound uremic toxin concentrations and patient survival | Blood samples are analysed for protein-bound toxins (mg/dL) in one High Performance Liquid Chromatography run. Survival is measured (in months). | 10/2015 - 12/2018 |