Type 1 Diabetes Mellitus (DM)
Coeliac disease and dermatitis herpetiformis is more common in people with certain other autoimmune diseases, such as Type 1 diabetes mellitus (T1DM). This association is probably due to both diseases having a common genetic predisposition. HLA-DQB1 is present in the majority of patients with both conditions (1,2) Autoimmune thyroid disease may also co-exist with both coeliac disease and Type 1 diabetes. It has been shown that when coeliac disease is diagnosed before diabetes the clinical presentation of diabetes is more severe and there is a higher prevalence of multiple autoimmune diseases (3). In patients with coeliac disease and T1DM adherence to a gluten-free diet helps with diabetic control (5,6). It has thus been suggested that all patients with T1DM and their first-degree relatives should be screened for coeliac disease. At present there is no specific policy on screening for coeliac disease in adults with T1DM but Scottish guidelines recommend that young people with T1DM should have coeliac serology checked at diagnosis (4).
There is no increased risk of coeliac disease in patients with Type 2 diabetes mellitus(7).
How common is Type 1 diabetes in coeliac disease?
In the general population T1DM affects approximately 0.75% of people and coeliac disease affects 1%. T1DM occurs in about 5% of patients with coeliac disease, and when patients with type 1 diabetes are screened for coeliac disease 6-10% are antibody positive and/or biopsy positive (8,9,10).
Coeliac disease should therefore be suspected in any patient who has T1DM with gastrointestinal symptoms or unexplained anaemia.
Presentation and symptoms of coeliac disease in diabetes
The symptoms of coeliac disease are very diverse, ranging from severe to vague or mild symptoms. The diagnosis of coeliac disease can precede that of T1DM, but in most cases (about 90%) diabetes is diagnosed first (11). Probably because T1DM generally has an acute onset, which is easily identifiable as early symptoms. The varied and atypical presentation of coeliac disease is very often missed or symptoms of ill health are attributed to the already diagnosed diabetes. Malabsorption commonly occurs in patients with undiagnosed coeliac disease and T1DM. Recurrent hypoglycaemia has been reported as a presenting sign of coeliac disease in individuals with T1DM (12) and unstable diabetes and growth failure in children with diabetes may indicate the presence of coeliac disease (13).
How to diagnose coeliac disease?
Serum anti transglutaminase (TGA) and anti-endomysial antibodies (EMA) are considered to be sensitive diagnostic markers for coeliac disease. However the presence or absence of IgA deficiency has been reported in a group of patients with T1DM and it has therefore been suggested that IgG1 EMA should also be sought whenever a patient with T1DM undergoes screening for coeliac disease (14).
It is possible to have a negative blood test yet still have coeliac disease. Some patients with T1DM may be negative for CD antibodies early in their diagnosis but may later become antibody positive. Some patients with positive antibodies may have negative small-bowel biopsies and may have latent coeliac disease. There is therefore a case for monitoring of the situation: any screening strategy should consider repeat serological testing at intervals (15).
What are the benefits of diagnosis of coeliac disease in diabetes?
A range of short and long term improvements are possible in individuals with T1DM who are diagnosed with coeliac disease and follow a gluten-free diet.
These include:
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Normal haematological findings including, haemoglobin, folate and B12 levels.
Both T1DM and coeliac disease are associated with long-term complications so there is an expectation that when the two diseases co-exist there is the potential for the development of any associated complications.
Dietary management of Type 1 diabetes and coeliac disease
Dietary management of the combined diseases requires professional guidance from a Registered Dietitian. There are British Society of Gastroenterology guidelines on the management of coeliac disease. These recommend dietetic intervention at diagnosis, 3-months, 6-months and annual review (18). The role of the dietitian is well documented in diabetes management and there are nutrition guidelines and recommendations for dietetic intervention in diabetes care (19,20).
Dietary management needs to aim to normalize blood glucose levels as well as support adherence to the gluten-free diet. Particular care needs to be taken in dietetic provision in children with coeliac disease and T1DM diabetes with careful monitoring of growth and development parameters.
Reference:
1 Martin-Villa JM et al. Coeliac- and enteropathy-associated autoantibodies in Spanish insulin-dependent diabetes mellitus patients and their relation to HLA antigens. Journal of Diabetes and its Complications 2001;15:38-43.
2 Hervonen K et al. The occurrence of type 1 diabetes in patients with dermatitis herpetiformis and their first-degree relatives. British Journal of Dermatology 2004;150(1):136-8.
3 Valerio G et al. Severe clinical onset of diabetes and increased prevalence of other autoimmune diseases in children with coeliac diabetes diagnosed before diabetes mellitus. Diabetologia 2002;45(12):1719-22.
4 www.sign.ac.uk/pdf/sign55.pdf
5 Hansen D et al. High prevalence of celiac disease in Danish children with type 1 diabetes mellitus. Acta Paediatrica 2001;90:1238-43.
6 Saadah OI et al. Effect of gluten-free diet and adherence on growth and diabetic control in diabetics with celiac disease. Archives of Disease in Childhood 2004;89(9):871-6.
7Page SR et al. The prevalence of coeliac disease in adult diabetes mellitus. QJM 1994;87:631-37.
8 Gillet PM et al. High prevalence of celiac disease in patients with type 1 diabetes detected by antibodies to endomysium and tissue transglutaminase. Canadian Journal of Gastroenterology 2001;15:297-301.
9 Hansen D et al. High prevalence of coeliac disease in Danish children with type 1 diabetes mellitus. Acta Paediatrica 2001;90:1238-1243.
10 Arato A et al. Frequency of coeliac disease in Hungarian children with type 1 diabetes mellitus. European Journal of Pediatrics 2003;162:1-5.
12 Barera G et al. Screening of diabetic children for coeliac disease with antigliadin antibodies and HLA typing. Archives of Disease in Childhood 1991;66:491-494.
13 Bradbury BL, Scarpello JHB. Recurrent hypoglycaemia as the presenting symptom of coeliac disease in a patient with Type 1 diabetes mellitus. Pract Diab Int 16: 89-90.
14 Holmes GKT. Coeliac disease and Type 1 diabetes - the case for screening. Diabetic Medicine 2001;18:169-77.
15 Picarelli H et al. Anti-endomysial antibody of IgG1 isotype detection strongly increases the prevalence of celiac disease in patients affected by type 1 diabetes mellitus. Clinical and Experimental Immunology 2005;142(1):111-15.
16 Smith CM et al. Prevalence of celiac disease and longitudinal follow-up of antigliadin antibody status in children and adolescents with Type 1 diabetes mellitus. Paediatric Diabetes 2000;1(4):199-204
17 Mora et al 1993 - in osteoporosis ref
18 Sanchez-Albisua I et al. Coeliac disease in children with Type 1 diabetes mellitus: the effect of the gluten-free diet. Diabetic Medicine 2005;22:8
19 BSG guidelines www.bsg.org.uk
20 Nutrition Subcommittee of the Diabetes Care Advisory Committee of Diabetes UK. The implementation of nutritional advice for people with diabetes. Diabetic Medicine 2003;20:786-807.
21 Diabetes and Nutrition Study Group (DNSG) of the European Association for the Study of Diabetes Evidence-based nutritional approaches to the treatment and prevention of diabetes mellitus. Nutrition Metabolism and Cardiovascular Disease 2004;14:373-394.
