The How and Why of Celiac Disease
Celiac expert Stefano Guandalini tells why you may need another celiac disease test, and more.
This month I had the pleasure of interviewing world-renowned celiac disease expert Stefano Guandalini, M.D. Guandalini is founder and medical director of the University of Chicago Celiac Disease Center (http://www.celiacdisease.net/). His work resulted in the revision of 20-year-old guidelines for diagnosing celiac disease. These new guidelines are used worldwide both for pediatric and adult celiac patients. Guandalini joined the University of Chicago Department of Pediatrics in 1996, where he serves as section chief of the Department of Pediatrics Gastroenterology, Hepatology and Nutrition.
What is your recommendation for giving patients with type 1 diabetes a celiac disease test?
Every patient diagnosed with type 1 diabetes should be screened for celiac disease immediately after their diagnosis. The prevalence of celiac disease is higher among people with type 1 diabetes -- approximately 8 to 10 percent of have celiac disease.
I also recommend that, if a patient was given a celiac disease test immediately after diagnosis and tested negative, they should be retested for celiac disease periodically. Although a time frame for retesting is not formally recommended, in my opinion they should be retested for celiac disease every two to three years. The reason for this is that it has been found that approximately 7 to 8 percent of people with type 1 diabetes are diagnosed with celiac disease at the time of their first screening, but the prevalence of celiac disease in patients with type 1 diabetes progressively rises to 8 to10 percent 10 years after the initial testing.
Do we know the reason for the high prevalence of celiac disease among people with type 1 diabetes?
There are two likely reasons for the higher prevalence. First, certain autoimmune conditions share the same genetic predisposition. We know that both type 1 diabetes and celiac disease are autoimmune diseases, and they share genetic similarities. The second hypothesis is that celiac disease may "open the way" to other autoimmune conditions, such as Addison's disease or thyroid disease. This hypothesis, which has some evidence supporting it, is that the disturbed intestinal permeability (which occurs from intestinal damage when people with celiac disease consume gluten) may trigger other antigens to enter the bloodstream and lead to other autoimmune conditions. For instance, research has shown that among children newly diagnosed with celiac disease, approximately 50 percent had elevated auto-antibodies (which are produced in response to foreign substances entering the bloodstream). When these same children were treated with a gluten-free diet and examined one year later, most of the auto-antibodies returned to normal.
Do people with type 1 diabetes present with any unique symptoms of celiac disease?
No, and actually gastrointestinal symptoms may be minimal or absent in some people. We cannot rely on gastrointestinal symptoms for diagnosis of celiac disease. The next question people usually ask is: Do these people need to be on a gluten-free diet if they do not have symptoms of celiac disease? The answer is yes. This is not specific for those with type 1 diabetes, but there have been studies showing that if people continue to eat gluten after being diagnosed with celiac disease, they are at risk for developing other complications such as osteopenia, osteoporosis, iron deficiency anemia, fatigue, and more serious complications such as intestinal cancers.
Have you seen improved blood glucose control among patients with type 1 diabetes after being diagnosed and treated for celiac disease?
The gluten-free diet does not improve or worsen control of their diabetes.
Have you seen patients with type 1 diabetes presenting with more frequent hypoglycemia due to malabsorption of food when taking insulin?
No. Data obtained by looking at intestinal biopsies in patients with type 1 diabetes and celiac have shown that the vast majority of them do not have severe changes to their intestines. Since the intestinal damage is minimal, malabsorption is also typically minimal. However, some physicians have reported the occasional patient with more severe intestinal damage and malabsorption, leading to occasional hypoglycemia, before the institution of a gluten-free diet.
Many people say that depression is a side effect or complication of diabetes. Without discounting the association of the psychological condition with the physical one, I'm not convinced that our high and/or unstable glucose levels are directly responsible for that change in our mental state. My belief is that the unrelenting need for self-care, for following the sort of care schedules that can drive licensed, professional caregivers crazy, is what overwhelms us...