Protein energy wasting and mortality in patients with chronic kidney disease on maintenance hemodialysis

Abstract

Protein energy wasting (PEW) is the depletion of protein/energy stores observed in the most advanced stages of chronic kidney disease (CKD). PEW is highly prevalent among patients on chronic dialysis, and is associated with adverse clinical outcomes, high morbidity and mortality rates. The pathogenesis of PEW is multifactorial. Loss of appetite, reduced intake of nutrients and altered lean body mass anabolism/catabolism play a key role. Nutritional approach to PEW should be based on a careful and periodic assessment of nutritional status and on timely dietary counseling. When protein and energy intakes are reduced, nutritional supplementation by means of specific oral formulations administered during the hemodialysis session may be the first-step intervention, and represents a valid nutritional approach to PEW prevention and treatment since it is easy, effective and safe. When oral supplementation fails, intradialytic parenteral nutrition can be implemented in selected patients. Different nutritional approaches are currently available to prevent and treat PEW, and they should be carefully individualized. Thus, this retrospective observational study investigated the relationship between mortality and parameters for malnutrition such as body composition, malnutrition inflammation score (MIS), dietary intake, and biochemical data in the end stage renal disease patients on maintenance hemodialysis (MHD). One hundred thirty three patients were enrolled, and followed up for 10 years. Body composition was measure by bio-impedance analysis, dietary intake was estimated using 24 h recall on non-dialysis day. The MIS was used to evaluate the malnutrition inflammation complex syndrome. We used the Kaplan-Meier curves, log-rank, and Cox’s proportional hazards model were used to analyze survival in relation to MIS, BMI, normalized protein catabolic rate (nPCR), energy intake, protein intake, albumin and prealbumin. During 10 year follow-up, 52 patients were died. Survivor had significantly higher level of nPCR, energy intake and protein intake, while lower level of MIS. Energy intake < 25 kcal/kg and MIS ≥5.5 were independent variables associated with to all-cause mortality after adjusted age, sex, kt/V and Charlson comorbidity index. In conclusion, optimal dietary energy intake would be more important than anthropometric, body composition or laboratory indices for the survival of MHD patients.