Dietary gluten induces endogenous NO production in children with coeliac disease • 514

Abstract

Introduction: Increased intestinal NO production has been reported in inflammatory bowel disease. NO is oxidized to nitrite and nitrate(NOx) which is excreted in the urine. The urinary NOx/ creatinine-ratio can be used as an indicator for endogenous NO production. Aims: To evaluate whether in coeliac disease the urinary NOx/creatinine-ratio is dependent on gluten intake. Results of healthy controls are given for comparison. Patients: The following patient groups were evaluated: I. Active coeliac disease (n=22), mean age 3.6 years (range 1.0-12.8). II. Healthy controls (n=11), mean age 13.2 years (range 9.6-16.2). III. Patients with unconfirmed coeliac disease on a gluten-free diet for at least one year(n=8), mean age 3.2 years (range 2.1-4.7), were subjected to a gluten-challenge. Urine samples were taken before, 1, 3, 7 and 21 days after starting gluten-challenge. The diagnosis was biopsy confirmed in 5 patients and excluded in 3. Methods: The Griess reagent method was used for the measurement of urinary NOx. The NOx/creatinine- ratio was expressed in mmol/mmol. Results: Mean (SEM) urinary NOx/creatinine-ratios were 1.78(0.33) in coeliac disease patients and 0.11(0.02) in healthy controls(p<0.0001). All patients with confirmed coeliac disease showed urinary NOx/creatinine-ratios above our normal reference value (0.3 mmol/mmol) within 3 days of gluten challenge (table).Conclusion: The high urinary NOx/creatinine-ratios in children with coeliac disease are dependent on gluten intake.