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

Dialysis, Nutrition, Quality of Life

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.

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.