In his response to a reader's query about the connection between celiac disease and type 1 diabetes (CONSULTANT, September 1, 2004, page 1312), Dr David Wyatt recommends that all children with type 1 diabetes be screened for celiac disease. This recommendation raises a few questions. First, if a patient tests positive for celiac disease but has no symptoms and is developing normally, do any studies show a benefit from following a gluten-free diet? Second, do patients with asymptomatic celiac disease also have an increased risk of lymphoma?
—— Karol Davis, MD
Kansas City, Kan
I do not advocate a gluten-free diet for asymptomatic patients who have a positive blood screening test. They must also have a positive result on a bowel biopsy. If the results of biopsy are negative, I repeat the biopsy in 2 to 3 years (or when symptoms occur, if sooner). If the results of a second biopsy are negative, I repeat the biopsy only if symptoms develop.
Many patients with type 1 diabetes who have positive biopsy results exhibit improved glucose control on a gluten-free diet. This effect may occur because:
•A stricter diet enhances compliance with diabetic dietary restrictions.
•Recovery of the bowel facilitates smoother glucose absorption.
•Interaction (via gut hormones) between the bowel and glucose metabolism elsewhere in the body is improved.
Some patients report that they feel better on the diet, even though they did not initially have any significant GI symptoms. However, some patients do not seem to benefit clinically from a gluten-free diet, even though the bowel mucosa heals (based on biopsy results).
The gastroenterologists at my institution consider all patients with celiac diseaserelated bowel changes at risk for future bowel cancer or lymphoma because of the chronic irritant nature of the disease. However, there have not been any long-term controlled trials in patients with type 1 diabetes, and there likely never will be.
Unfortunately, the gluten-free diet is not appealing to some patients and is more expensive than a normal diet. Thus, patients who do not perceive an immediate clinical benefit often discontinue the diet. Their future risk is unknown.
—— David Wyatt, MD
Professor of Pediatrics
Director of Pediatric Endocrinology and Diabetes
Medical College of Wisconsin