Celiac disease in type 1 diabetes mellitus: What are the implications of early diagnosis?

Sir,

I read with interest the article by Bhadada et al1 on celiac disease in patients with type 1 diabetes mellitus (T1DM). In this retrospective study, the authors have compared children having celiac disease (CD) with T1DM and those with CD alone, and found that patients with CD alone are likely to be older and have more advanced disease when compared to the former group. All these findings are attributable to the fact that patients with T1DM are routinely screened for CD and hence are diagnosed even at asymptomatic stage, while those who present with symptoms of CD are likely to be older with overt manifestations of CD.

Association of CD with T1DM is a well-known phenomenon. Importance of this association is highlighted in view of the data suggesting that the patients with T1DM who have CD are more likely to have microvascular complications as compared to those without CD2. However, the effect of gluten-free diet (GFD) is not yet clear in this group of patients.

Importantly, up to two-thirds of individuals diagnosed with CD by screening patients with T1DM may be asymptomatic3. Elevated tissue transglutaminase IgA antibodies have been known to be spontaneously normalized in some patients with T1DM4. On the other hand, initially negative antibodies may become detectable at a later stage, hence there is a need for repeated testing in these individuals at least till the age of 10 yr from diagnosis of T1DM5.

While diagnosing asymptomatic patients with T1DM with CD one should take into consideration the added burden of two diseases at an early age, which remain with the patient for life and entail significant dietary and lifestyle changes. This is important since there is lack of clarity related to the impact of GFD on patients with T1DM with asymptomatic CD. A study which is likely to clarify these issues is an ongoing randomized controlled trial in patients with T1DM with asymptomatic CD to look for the effect of GFD on glycaemic control, bone density and general well-being6. A recent review article on the basis of available data has suggested that a small bowel biopsy must be done in patients with T1DM with persistently detectable antibodies and should lead to advice of GFD even in those asymptomatic for CD7.