Molly Wong Vega1, Poyyapakkam R Srivaths2. 1. Department of Pediatrics, Renal Section, Baylor College of Medicine, Houston, Texas. Electronic address: mrvega@texaschildrens.org. 2. Department of Pediatrics, Renal Section, Baylor College of Medicine, Houston, Texas.
Abstract
OBJECTIVE: Protein energy wasting is difficult to assess in pediatric hemodialysis (HD) populations because of fluid shifts. Body composition (BC) analysis aids in monitoring nutrition therapy's effects on fat and lean mass. Air displacement plethysmography (ADP) is a "practical" gold standard for fat mass (FM) measurements. We aim to compare BC measures in a pediatric HD population via anthropometry, ADP, and bioelectrical impedance (BIA). DESIGN: The study was prospective cohort study and the setting was 1 pediatric HD unit in Houston, Texas. SUBJECTS: A total of 15 pediatric and young adult patients receiving maintenance HD. INTERVENTION: ADP, BIA, and anthropometry were obtained mid-week post HD for 3 consecutive months. MAIN OUTCOME MEASURE: The primary outcome was the difference in FM as defined by various assessment methods. Secondary outcomes included correlations with anthropometry. RESULTS: ADP demonstrated a strong positive correlation to body mass index, mid-upper arm circumference, and triceps skin fold (all P < .0001). No differences in FM assessment using ADP or BIA were found except in males with advanced tanner (P = .0004). BIA underestimated FM in obese subjects (P = .005). Analysis of malnutrition status by mid-upper arm circumference revealed an overestimation of FM in BIA measures (P = .02). CONCLUSIONS: This is the first pediatric dialysis study using ADP to assess BC. Estimation of FM in pediatric HD patients via ADP and BIA has significant error rates in 2 populations: (1) males tanner ≥4: BIA underestimates FM and (2) weight extremes: BIA underestimates FM for obese and overestimates FM for malnourished. BIA should be used with caution in these populations when estimating fluid content and leads to false estimates of dry weight. ADP is a useful adjunct in assessment of nutritional status via BC in pediatric HD patients.
OBJECTIVE: Protein energy wasting is difficult to assess in pediatric hemodialysis (HD) populations because of fluid shifts. Body composition (BC) analysis aids in monitoring nutrition therapy's effects on fat and lean mass. Air displacement plethysmography (ADP) is a "practical" gold standard for fat mass (FM) measurements. We aim to compare BC measures in a pediatric HD population via anthropometry, ADP, and bioelectrical impedance (BIA). DESIGN: The study was prospective cohort study and the setting was 1 pediatric HD unit in Houston, Texas. SUBJECTS: A total of 15 pediatric and young adult patients receiving maintenance HD. INTERVENTION: ADP, BIA, and anthropometry were obtained mid-week post HD for 3 consecutive months. MAIN OUTCOME MEASURE: The primary outcome was the difference in FM as defined by various assessment methods. Secondary outcomes included correlations with anthropometry. RESULTS:ADP demonstrated a strong positive correlation to body mass index, mid-upper arm circumference, and triceps skin fold (all P < .0001). No differences in FM assessment using ADP or BIA were found except in males with advanced tanner (P = .0004). BIA underestimated FM in obese subjects (P = .005). Analysis of malnutrition status by mid-upper arm circumference revealed an overestimation of FM in BIA measures (P = .02). CONCLUSIONS: This is the first pediatric dialysis study using ADP to assess BC. Estimation of FM in pediatric HDpatients via ADP and BIA has significant error rates in 2 populations: (1) males tanner ≥4: BIA underestimates FM and (2) weight extremes: BIA underestimates FM for obese and overestimates FM for malnourished. BIA should be used with caution in these populations when estimating fluid content and leads to false estimates of dry weight. ADP is a useful adjunct in assessment of nutritional status via BC in pediatric HDpatients.