Effect of gluten-free diet and adherence on growth and diabetic control in diabetics with coeliac disease

Aims: To study the effect of gluten-free diet on growth and diabetic control of children with type 1 diabetes mellitus and coeliac disease. Methods: Twenty one children ( mean age 7.5 years, range 1.6 - 12.9) with type 1 diabetes, primarily initially identified on the basis of symptoms and consecutively diagnosed with coeliac disease by biopsy over a 10 year period, were matched by sex, age at onset, and duration of diabetes with two diabetic controls without coeliac disease. Weight, height, haemoglobin A1c, and insulin requirements were measured before and for 12 months after the diagnosis and treatment of coeliac disease. Dietary awareness and adherence were assessed by structured questionnaire. Results: A gluten-free diet resulted in a significant increase in weight-for-age z scores at 12 months after diagnosis ( mean increase in z score 0.33) and in BMI ( mean increase in z score 0.32). Increases in height did not achieve statistical significance. Controls showed no significant changes in weight, height, or BMI over the same period. Insulin dosage at diagnosis was less in coeliacs than in controls ( mean difference 0.16 units/kg/day), but was similar to controls once a gluten-free diet had been established. Questionnaires were obtained in 20 patients. There appeared to be a relation between dietary awareness/adherence and growth parameters, but the small number of patients with "poor/fair'' dietary adherence prevented meaningful analysis of this group. Conclusion: Identification and dietary treatment of coeliac disease in children with diabetes improved growth and influenced diabetic control. Evaluation of the outcome of treatment of coeliac disease in diabetics should include assessments of gluten intake.