Risk factors for developing hyperoxaluria in children with Crohn’s disease

Background For the purpose of a better understanding of enteric hyperoxaluria in Crohn’s disease (CD) in children and adolescents, we investigated the occurrence and risk factors for development of hyperoxaluria in those patients. Methods Forty-five children with CD and another 45 controls were involved in this cross-sectional study. Urine samples were collected for measurement of spot urine calcium/creatinine (Ur Ca/Cr), oxalate/creatinine (Ur Ox/Cr), and citrate/creatinine (Ur Citr/Cr) ratios. Fecal samples were also collected to detect the oxalyl-CoA decarboxylase of Oxalobacter formigenes by PCR. Patients were classified into 2 groups: group A (with hyperoxaluria) and group B (with normal urine oxalate excretion). The disease extent was assessed, and the activity index was calculated. Results According to the activity index, 30 patients (66.7%) had mild disease and 13 patients (28.9%) had moderate disease. There was no significant difference in Ur Ox/Cr ratio regarding the disease activity index. O. formigenes was not detected in 91% of patients in group A while it was detected in all patients in group B ( p < 0.001). By using logistic regression analysis, the overall model was statistically significant when compared to the null model, ( χ 2 (7) = 52.19, p < 0.001), steatorrhea ( p = 0.004), frequent stools ( p = 0.009), and O. formigenes ( p < 0.001). Conclusion Lack of intestinal colonization with O. formigenes , steatorrhea, and frequent stools are the main risk factors for development of enteric hyperoxaluria in CD patients. Identifying risk factors facilitates proper disease management in future studies. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information