People with coeliac disease are more likely to have another autoimmune disease. Coeliac disease is considered to be more prevalent in people with autoimmune conditions such as Type 1 diabetes and autoimmune thyroid disease.
It has been suggested that the chance of developing other autoimmune disorders is increased when diagnosis of coeliac disease is delayed.
Type 1 diabetes
People with Type 1 diabetes are at a higher risk than the general population of having coeliac disease. Between 4 and 9% of people with Type 1 diabetes also have a diagnosis of coeliac disease compared with 1% of the general population. The NICE guideline recommends that anyone with Type 1 diabetes should be screened for coeliac disease.
The association is probably because both diseases have a common genetic predisposition. HLA-DQB1 is the gene present in the majority of people with both conditions. There is no increased risk of coeliac disease in people with Type 2 diabetes.
Joint BSPGHAN and Coeliac UK guidelines 2013 recommended if the DQ2 or DQ8 gene is present but tTG antibody test is negative, children should be retested in three years or if they become symptomatic. However, we would refer to the updated NICE guideline which recommends that healthcare professionals should have a low threshold for retesting people with Type 1 diabetes if they develop any symptoms consistent with coeliac disease.
For patients diagnosed with diabetes and coeliac disease, blood glucose levels should be monitored closely following coeliac disease diagnosis as insulin levels often need to be altered due to the increased absorption of carbohydrate. NICE guidance on Type 1 diabetes in adults recommends ‘Measuring HbA1c levels every 3 to 6 months and to consider measuring HbA1c levels more often in adults with Type 1 diabetes if the person’s blood glucose is suspected to be changing rapidly; for example, if the HbA1c level has risen unexpectedly above a previously sustained target’. Gluten free alternatives to wheat containing bread, pasta, biscuits and flour have approximately the same carbohydrate content as their gluten containing counterparts, and therefore should not necessarily compromise the diet.
Dietary management of the combined diseases requires professional guidance from a dietitian. The aim of dietary management is to improve blood glucose control as well as support people with advice on the gluten free diet. Children with coeliac disease and Type 1 diabetes should have their growth and development carefully monitored.
The NICE guideline on Type 1 diabetes in adults provides a number of recommendations on dietary management, such as;
- Offer nutritional information individually and as part of a diabetes education programme.
- Offer dietary advice to adults with Type 1 diabetes to adults with type 1 diabetes as part of structured education programmes for self management.
- Do not advise adults with Type 1 diabetes to follow a low glycaemic index diet for blood glucose control.
- Discuss the hyperglycaemic effects of different foods an adult with Type 1 diabetes wishes to eat in the context of the insulin preparations chosen to match those food choices.
- Be aware of appropriate nutritional advice on common topics of concern and interest to adults living with Type 1 diabetes, and be prepared to seek advice from colleagues with more specialised knowledge. Suggested topics include coeliac disease
Autoimmune thyroid disease
People with autoimmune thyroid disease have an increased prevalence of coeliac disease (1 - 4% compared with 1% in the general population). Patients often gain weight once they have started a gluten free diet. If your patients have unexplained weight gain following diagnosis with coeliac disease, and this does not level out, it would be beneficial to test for this condition.
Autoimmune liver disease
Abnormal liver biochemistry is common in untreated and undiagnosed coeliac disease. NICE recommends ‘those with persistently raised liver enzymes with unknown cause should be considered for testing for coeliac disease. If concerns are raised in the annual review, the healthcare professional should assess the need for specific blood tests. If liver function tests were high at diagnosis and there are ongoing concerns, further testing may be required.