Celiac Disease with Type 1 Diabetes
A 7 year old boy with type 1 diabetes has fallen from the 50th to the 10th weight percentile over 6 months, with his height velocity slowing. His HbA1c is 6.0% and his insulin requirement has decreased. He has loose stools, a distended abdomen and wasted buttocks. Haemoglobin is 10.2 g/dL, ferritin 6 µg/L and TSH 2.1 mIU/L. What is the most likely cause of his growth failure?
- A.Growth hormone deficiency
- B.Autoimmune hypothyroidism
- C.Persistently poor glycemic control
- D.Celiac diseaseCorrect
Explanation
Falling weight and height together with loose stools, abdominal distension, wasted buttocks and iron deficiency anaemia in a child with type 1 diabetes is the classic presentation of coeliac disease, which affects up to 10% of these children because of shared HLA DQ2 and DQ8 haplotypes. Malabsorption of nutrients and iron explains both the growth failure and the microcytic anaemia with a very low ferritin. The reassuringly low HbA1c and the falling insulin requirement are not signs of good control but a red flag: impaired carbohydrate absorption reduces postprandial glucose excursions and causes unexplained hypoglycaemia. The pattern of decreased weight and decreased height distinguishes coeliac disease from hypothyroidism, which classically causes weight gain with poor linear growth; here the normal TSH excludes that. Poorly controlled diabetes can impair growth, the extreme being Mauriac syndrome with hepatomegaly and cushingoid features, but that requires chronic hyperglycaemia and would give a high, not a normal, HbA1c. Growth hormone deficiency causes proportionate short stature with preserved or increased weight for height and no gastrointestinal symptoms or iron deficiency. The next step is tissue transglutaminase IgA with a total IgA level, followed by referral for confirmatory small bowel biopsy before any gluten free diet is started. A strict gluten free diet restores growth, corrects the anaemia and stabilises insulin requirements.
Why each option
- A.
- Growth hormone deficiency gives proportionate short stature with normal or increased adiposity, without diarrhoea or iron deficiency.
- B.
- Hypothyroidism causes weight gain with poor linear growth, and the normal TSH of 2.1 mIU/L excludes it here.
- C.
- Growth failure from poor control requires sustained hyperglycaemia; this child's HbA1c is 6.0% with falling insulin requirements.
- D.
- Correct. Weight and height both falling, diarrhoea, abdominal distension, iron deficiency and reduced insulin needs point to coeliac disease.
Reference: Nelson Textbook of Pediatrics, 22nd ed., 2024, Celiac Disease
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