Role of Hypercalciuria in Recurrent Urinary Tract Infection in Children

Hypercalciuria has been considered a predisposing factor for recurrent urinary tract infection (UTI) in recent studies. The mechanism may be related to uroepithelial injury by calcium microcrystals. The aim of this study was to evaluate the association of idiopathic hypercalciuria with recurrent UTI in children. In this cross-sectional study, the urine calcium/creatinine ratio of 40 children aged 2-16 years with recurrent urinary tract infection (without urinary tract anomalies and voiding dysfunction) was compared with 40 age- and sex-matched healthy children. Hypercalciuria was defined as a calcium/creatinine ratio more than 0.21 in a spot urine test. Recurrent UTI was defined as at least 3 episodes of UTI during 1 year or 2 episodes in 6 months. The mean age of the patients was 5±2.22 years and mean age of the control group was 5.13±1.98 years. The mean calcium/creatinine ratio in the case group (0.21±0.17) was significantly higher than the control group (0.08±0.08) (p<0.05). Hypercalciuria was detected in 47.5% of the patients in the case group and in 7.5% of the participants in the control group (P<0.001). The history of familial urolithiasis was positive in 21% of the hypercalciuric patients. There was no significant difference in the frequency of urinary symptoms between hypercalciuric and normocalciuric patients with recurrent UTI. The episodes of UTI reduced in 12/19 (63.2%) of the patients after the treatment of hypercalciuria. Children who suffer from recurrent UTI in the absence of urinary tract anomalies should be checked for hypercalciuria. Control of hypercalciuria may decrease UTI episodes.