Renal size and renal tubuler functions in children with protein-energy malnutrition

SUMMARY Ayfer Gözü MD, Dicle Universty Medical Faculty, Department of Pediatrics Diyarbakır 2004. Renal size and renal tubular functions in children with protein-energy malnutrition (PEM). In this study, 80 children who were diagnosed as protein-energy malnutrition (PEM) at Pediatrics Department of Dicle University Hospital were enrolled. The mean age of patients was 29.2+19.7 months (3-66 months). Of all patients, 35 of them (43.7 %) were girls and 45 (56.3 %) were boys. According to Waterlow malnutrition classification, 54 patients had severe PEM, 20 had moderate and six had mild PEM. Of patients with severe PEM, 51 had marasmus and three had marasmic kwashiorkor according to Wellcome-Thrust classification. Remaining 26 patients were mild or moderately malnourished. Renal tubular functions in those patients with malnutrition were compared with age and sex matched 32 control subjects. Correlation analysis was performed in 80 patients with PEM and 84 control subjects (a total of 164 subjects). The malnourished patients had significantly lower levels of serum sodium, potassium, phosphorus, creatinine and total cholesterol. Urine potassium, phosphorus, magnesium and creatinine levels were also significantly low. In patient group glomerular filtration rate (GFR) was lower while urinary calcium/creatinine (Ca/Cr) ratio was significantly higher. Among renal tubular index parameters, fractional excretion of sodium (FENa) showed no difference, whereas decrease infractional potassium excretion (FEK) value and increase in tubular reabsorption of phosphorus (TRP) was significant in patient group compared with controls. The correlation between blood pressure and GFR was significant. Renal size was significantly lower in malnourished children. Renal size was found to be significantly correlated with age, body surface area, triceps skin fold thickness and upper mid arm circumference. A positive correlation of FEK and a negative correlation of TRP was present with bilateral renal size and right renal width and parenchymal thickness whereas no correlation was present for FENa. In conclusion in patients with PEM, the nutritional defect cause a tendency in impairment of renal tubular functions. Ultrasonographically determined renal size was found to be correlated with somatic parameters such as body weight, body surface area, triceps skin fold thickness and upper mid arm circumference. There was no difference in renal size and tubular functions of boys and girls. Furthermore changing in mineral excretions such as hipercalciuria may cause in trigger formation of nephrolithiasis. Key words: Protein-energy malnutrition, renal tubuler functions, renal size IV