Nutrition and Growth in Relation to Severity of Renal Disease in Children

Practical joint medical/dietetic guidelines are required for children with chronic renal insufficiency (CRI). Nutritional status and growth were compared in 95 children (59 male) > 2 years age with CRI, grouped following [51Cr]-labelled EDTA glomerular filtration rate (GFR, ml/min/1.73 m2) estimations into 'normal' kidney function [GFR > 75 (mean 104 (SD 18.9), n = 35], mild (GFR 51-75, n = 23), moderate (GFR 25-50, n = 19) and severe CRI (GFR < 25, n = 18). Anthropometry [weight (wt.), height (ht.), and body mass index (BMI)], laboratory investigations and a 3-day dietary record were obtained. All anthropometric indices deteriorated with worsening renal function, from mean SD scores for wt., ht. and BMI in 'normal' children of 0.32 (SD 1.2), 0.4 (SD 1.0) and 0.1 (SD 1.3), respectively, to values of -1.28 (SD 1.1; P < 0.001), -1.52 (SD 1.1; P < 0.001) and -0.42 (SD 1.1; NS) in severe CRI. Mean total energy intake decreased from 103% (SD 17) estimated average requirement (EAR) in 'normal' children to 85% EAR (SD 27; P = 0.004) in severe CRI. Mean serum PTH concentrations (normal laboratory range 12-72 ng/l) were higher in moderate [67 ng/l (SD 58), P < 0.001] and severe CRI [164 ng/l (SD 164), P < 0.001] and mean serum phosphate concentrations were higher in severe CRI (1.54 mmol/l (SD 0.17), P = 0.009) compared to 'normal'. Disturbances in nutritional intakes, bone biochemistry and growth occur early in CRI and suggest the need for joint medical/dietetic intervention in children with mild and moderate CRI, in addition to those with more severe CRI.