Metabolic Evaluation in Paediatric Urolithiasis: A 4-Year Open Prospective Study

Abstract

Introduction: Children with urolithiasis are associated with considerable morbidity and commonly associated with metabolic abnormalities. By treating these abnormalities stone formation is prevented.

Objectives: To study the metabolic risk factors of urolithiasis in children and compare them with literature.

Materials and methods: In open, prospective and observational study, 75 children were evaluated from August 2010 to June 2014. In all patients' dietary history, water intake and results of laboratory findings were recorded. All urine samples obtained from patients were without dietary restrictions. Reference paediatric 24 hour urinary parameter was used according to western literature.

Results: We investigated 75 patients with urolithiasis. Low urine volume was found in 49 patients which is comparable with previous studies indicating simple intervention as to increase water intake. Low calcium intake was found in 44 patients suggesting that low calcium intake is associated with higher incidence of urolithiasis due to increased intestinal oxalate absorption. Hypocalcaemia was found in 32 patients and 24 hour urinary abnormality was found in only 16 patients'. Both these finding does not support previous literature. Stone analysis finding does not correlate with urinary finding.

Conclusions: Low urine volume secondary to low water intake is predominant finding. Hypocalcaemia is major metabolic abnormality in contradiction to western literature. There are no nomograms for urinary excretion of Calcium, uric acid, oxalate and citrate in Indian children. Keeping the optimum blood calcium level & increased fluid intake can prevent stone formation in children.

Keywords: Hypercalciuria; Hypocalcaemia; Urinary tract infections; Urine volume.