Phase angle and mid arm circumference as predictors of protein energy wasting in renal replacement therapy patients

Abstract

Objective: to analyze the association between phase angle (PA) and mid arm circumference (MAC) with protein energy wasting (PEW) in renal replacement therapy (RRT) patients. Methods: cross-sectional study. Hemodiafiltration (HDF) and automated peritoneal dialysis (PD) patients were enrolled in the study. MAC and body composition were measured using impedance bioelectric (BIA); PA, fat free mass (FFM), fat mass (FM) and ECW/TBW were obtained. Biochemical (serum albumin and cholesterol) and dietary data (energy and protein intake) were collected. Body mass index (BMI) was calculated. Patients were classified with PEW according to ISRNM criteria (low BMI, low albumin or cholesterol concentrations, low muscle mass and overhydration). Cut-off point of PA and MAC was obtained by ROC analysis. Logistic regression analysis was applied to evaluate the ability of both indicators to predict PEW. Results: sixty-nine patients were included in the study. Fifty-two (52%) were female. Thirty-nine (39%) patients had PEW. The ROC curve reveals that the optimal PA cut-off value for malnutrition risk was 4.64° with 77.8% sensitivity and 76.2% specificity. For MAC, a cut-off value of 29.6 cm shows a sensitivity of 66.6% and specificity of 69.0%. Both indicators showed significant association to PEW after multivariate adjustment. Conclusion: PEW is present almost in 39% of the RRT patients. PA and MAC are useful, simple and independents indicators for predicting PEW in chronic kidney disease patients on RRT.