Malnutrition and Renal Functions

BACKGROUND: Malnutrition is the most common cause of mortality in the world. Previous studies have confirmed significant alterations in renal functions in malnutrition. There is no data about urinary excretion of N-acetyl-β-D-glucosaminidase (NAG) and alanin aminopeptidase (AAP) in malnutrition.

OBJECTIVE: We investigated renal functions and renal tubular damage in children with malnutrition.

METHODS: Patients with malnutrition (n=20) and healthy controls (n=10) were included into the study. Blood and urine creatinine, Na, K, Cl, Ca, P, Mg and uric acid levels were studied. Urine N-acetyl-β--D-glucosaminidase (NAG) and alanin aminopeptidase (AAP) levels were measured. Endogen creatinine clearance, tubular P reabsorbtion (TRP), fractional Na and K excretion (FENa, FEK), renal failure index were calculated. Na/Cr, K/Cr, Ca/Cr, P/Cr, Mg/Cr, uric acid/Cr ratios were calculated.

RESULTS: Serum total protein, albumin, calcium and P levels were significantly lower in children with PEM (p<0.05). Urine P levels and endogen creatinine clearance were significantly lower in children with PEM (p<0.05). Calcium excretions, calcium/creatinine and sodium/potassium ratios were significantly higher in children with PEM (p<0.05). Urine NAG and AAP levels in children with PEM were low but there was no statistically significant difference (p>0.05).

DISCUSSION: We demonstrated that children with malnutrition had a decreased glomerular filtration rate and increased urinary excretion of Na, K, Ca. We consider that there is no tubular damage in malnutrition but there are functional changes in kidney.