Physical performance and protein-energy wasting in patients treated with nocturnal haemodialysis compared to conventional haemodialysis: protocol of the DiapriFIT study

Abstract

BackgroundPoor physical performance and protein-energy wasting (PEW) are health issues of major concern in haemodialysis patients. The conventional haemodialysis (CHD) regime, three times per week 3–5 h, is subject of discussion because of high morbidity and mortality rates. When patients switch from CHD to longer dialysis sessions, i.e. nocturnal haemodialysis (NHD), improvement in protein intake and increase in body weight is seen. However, it is unclear whether physical performance and more important aspects of PEW, such as body composition, improve as well. Therefore, the aim of this study is to investigate whether physical performance improves and PEW decreases, when patients switch from CHD to NHD. A second aim is to assess the influence of NHD on the biomarkers fibroblast growth factor-23 and sclerostin which are thought to be associated with malnutrition and mortality in patients on haemodialysis.MethodsThis study is a prospective multicentre cohort study with an inclusion aim of 50 patients: 25 patients in a control group (three times per week, 3–5 h CHD) and 25 patients in a nocturnal group (three times per week, 7–9 h NHD). Primary outcome is change in physical performance, measured by the Short Physical Performance Battery. Additional measurements are a 6-min walk test, handgrip strength, a physical activity questionnaire and physical activity monitoring. The secondary outcome of the study is PEW, which will be evaluated by body weight, dual-energy X-ray absorptiometry, bio-electrical impedance spectroscopy, mid-upper arm muscle circumference, subjective global assessment, visual analogue scale for appetite and dietary records. Laboratory measurements including fibroblast growth factor-23 and sclerostin, and quality of life assessed with the Kidney Disease Quality of Life-Short Form are also studied. In every patient, four repeated measurements will be performed during one year of follow-up.DiscussionThis study will investigate whether physical performance improves and PEW decreases when patients switch from CHD to NHD, compared to a control group who continue treatment with CHD. Strengths of this study are the comparison with a conventional haemodialysis cohort, and the broad variety of objective measurements combined with patient-reported outcomes of physical performance and PEW.Trial registration NTR4715, Netherlands Trial Register. Registered 30 July 2014.

Calculation of protein requirements; a comparison of calculations based on bodyweight and fat free mass

“…FFM was measured by air displacement plethysmography technology (BODPOD, Canada) in the ANAC population [11e14] and by bioelectrical impedance analysis (BIA) in the Amsterdam UMC population. Different impedance analyzers were used: BIS Xitron 400b (Xitron Technologies, USA) [16,17], Bodystat 1500 MDD (Bodystat, UK) [15,19], Bodystat 500 (Bodystat, UK) [19], BIA RJL Systems 101 (Clinton Township, USA) [18], Body Composition Monitor (Fresenius Medical Care, Bad Homburg, Germany) [20]. To calculate FFM in a similar way, the crude values (resistance and reactance) of the measurements were used to calculate FFM using the Geneva equation [21].…”

Are we overfeeding hemodialysis patients with protein? Exploring an alternative method to estimate protein needs

“…Measurements were mostly performed about 30 min after HD treatment, with the intention to measure the most optimal stability in a patient's body fluid compartments. More details regarding body composition and anthropometric measurements were previously described [18].…”

Dietary Protein Intake, Protein Energy Wasting, and the Progression of Chronic Kidney Disease: Analysis from the KNOW-CKD Study

“…However, the current study provided evidence that our working definition of PEW was valid at least in predicting CKD progression. Moreover, previous studies also did not strictly follow the recommendations because of the uncertainty in the diagnostic criteria [15,41,42]. Second, other nutritional data including daily calorie intake and body composition data including fat distribution and lean mass were not available because KNOW-CKD was not originally designed to identify the effect of DPI and PEW on renal outcomes.…”