Urinary stone disease in adults with celiac disease: prevalence, incidence and urinary determinants.

PURPOSE: Intestinal diseases may cause urinary stone disease via hyperoxaluria or diarrhea induced hyperconcentrated acidic urine. Data are missing on urinary stone disease in celiac disease, a common malabsorptive disorder. In this study we analyzed urinary stone disease and urine composition in adults with celiac disease.
MATERIALS AND METHODS: Study patients were 18 years or older, untreated, and newly diagnosed with celiac disease by serum markers and jejunal biopsy. Clinical presentation of celiac disease was assessed focusing on 5 disorders of diarrhea, and deficiency of calorie (low body mass index or weight loss), lipid (low prothrombin time or low serum lipids), iron (low hemoglobin or low serum ferritin) and calcium (low serum calcium or low bone densitometry). Urinary stone disease history was assessed by questionnaire (imaging, stone excretion, stone disruption/removal). Urinary variables were measured in a 24-hour collection in a subgroup of patients.
RESULTS: Under untreated conditions (baseline) urinary stone disease was independent of celiac disease presentation and more prevalent in patients with celiac disease than in a population sample used as a control (608 and 3,540, 7.9% and 5.0%, sex and age adjusted odds ratio 4.0, 95% CI 2.7-5.9). Excluding from analysis individuals with baseline urinary stone disease, the incidence of urinary stone disease history was not significantly different between the treated celiac disease (gluten-free diet) and control population (458 and 3,003, 2.4% vs 3.9%). The urine of untreated patients with celiac disease differed from that of healthy volunteers with 120% higher oxalate and 43% lower calcium (in 45 and 45, p <0.001). A gluten-free diet corrected urinary abnormalities (p <0.01).
CONCLUSIONS: Urinary stone disease risk is high in untreated patients with celiac disease independent of overt malabsorption. Hyperoxaluria is likely the underlying disorder. A gluten-free diet reduces urinary stone disease risk and oxaluria.