Coexisting conditions of coeliac disease

• Addison’s Disease

• Autoimmune liver conditions

• Autoimmune myocarditis

• Chronic thrombocytopenia purpura

• Depression/bipolar disorder

• Downs Syndrome

• Epilepsy

• Lymphoid malignancy

• Polyneuropathy

• Sjögren’s Syndrome

• Sarcoidosis

• Turner Syndrome

• Unexplained subfertility

Coeliac disease and type 1 diabetes often occur together. The prevalence of coeliac disease in persons with Type 1 diabeties is between 2% and 10%, depending on the age of the patient [1]. Coeliac disease also regularly occurs in first-degree relatives of type 1 diabetics.

Genetic similarities
The joint occurrence of the two diseases seems to be caused by a common genetic predisposition, namely, the occurrence of HLA-DQ2 and HLA-DQ8, known as histocompatibility genes.

Screening for coeliac disease amongst type 1 diabetics
Similarly to coeliac disease, the incidence of type 1 diabetes is rising, with a reported increase of 3% annually [2]. Less than 10% of patients with type 1 diabetes and coeliac disease report gastrointestinal symptoms [3], hence the recommendation to routinely screen for coeliac disease amongst this patient group. There is conflicting recommendations on how often repeat screening should be conducted. Current ESPGHAN guidelines recommend offering repeat screening every 2-3 years [4], whereas NICE suggest that the evidence is insufficient to recommend specific intervals for repeat screening following initial testing at diabetes diagnosis. In the vast majority of patients, coeliac diagnosis follows the diagnosis of type 1 diabetes.

Impact of a dual diagnosis
Evidence suggests that children with both type 1 diabetes and coeliac disease have lower weight and height standard deviation scores [5]. Furthermore, good adherence to a gluten free diet appears to result in steady improvement in height and weight whilst poor adherence is likely to result in continued growth impairment [6]. Among adults newly diagnosed with coeliac disease, glycaemic control has been shown to be significantly worse than amongst those with type 1 diabetes alone [7], although this effect may be reduced over time as the gluten free diet becomes well established [5,8]. Malabsorption of carbohydrates secondary to mucosal damage may explain the observation that episodes of hypoglycaemia are more common amongst patients with type 1 diabetes and coeliac disease in the six months before and after coeliac diagnosis. Once again, this finding is not repeated upon longer term follow up of patients, indicating gut recovery on a gluten free diet [9].

Long term risk
Unfortunately the prevalence of longer term complications associated with diabetes appear to be significantly greater for patients with both conditions, compared to those with diabetes/coeliac disease alone. Both risk of retinopathy [10] and subclinical atherosclerosis [11] is increased for those with a dual diagnosis in the longer term. Overall mortality risk after the first 5 years post coeliac diagnosis also appears to increase over time for those with both type 1 diabetes and coeliac disease [12].

Dietary therapy for diabetes and coeliac disease
A strict gluten free diet is required in order to maintain glycaemic control and reduce the short and long term complications of both diseases. The dietary management of both conditions is based on general healthy eating principles that apply to the population as a whole for the purpose of disease risk reduction and promotion of optimal health. Weight control and exercise are also paramount to glycaemic control.

Dermatitis herpetiformis is the cutaneous manifestation of coeliac disease triggered by the ingestion of dietary gluten. It is characterised by the appearance of a patchy, itchy rash and small blisters, most commonly found on the elbows, knees, buttocks and scalp. Unlike coeliac disease, it is more common in men than in women with an overall population prevalence of 1:3,300. Less than 10% of patients with dermatitis herpetiformis have gut symptoms, but most have total or subtotal villous atrophy upon histological examination [13]. As in coeliac disease, virtually all patients with Dermatitis Herpetiformis carry the HLA DQ2/DQ8 alleles.

Treatment of Dermatitis Herpetiformis
A strict, life-long gluten free diet is the mainstay of treatment for this condition. In the first month after the diagnosis or in the inflammatory phases of the disease, in which a gluten-free diet alone may not be enough to control the symptoms, several drugs can be used for variable periods of time, including Dapsone, sulfones or steroids. More than 70% of patients following a strict gluten free diet are able to slowly reduce their drug dose over a period of 2 years [14].

1. NICE Guideline NG20: Recognition, Assessment & Management of Coeliac Disease. National Institute of Clinical Excellence 2015.
2. Dabelea D, Mayer-Davis EJ, Saydah S et al. Prevalence of type 1 and type 2 diabetes among children and adolescents from 2001 to 2009. JAMA 2014; 311:1778-1786
3. Scaramuzza AE, Mantegazza C, Bosetti A, Zuccotti GV. Type 1 diabetes and celiac disease: The effects of gluten free diet on metabolic control. World J Diabetes 2013; 4: 130-134
4. Husby S, Koletzko S, Korponay-Szabó IR et al. European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the diagnosis of coeliac disease. J Pediatr Gastroenterol Nutr 2012; 54: 136-160
5. Fröhlich-Reiterer EE, Kaspers S, Hofer S, et al. Anthropometry, metabolic control, and follow-up in children and adolescents with type 1 diabetes mellitus and biopsy-proven celiac disease. J Pediatr 2011; 158: 589-593.
6. Akirov A, Hirsch G, Boyko V, et al. Celiac in type 1 diabetes children and youth–prevalence, metabolic control and growth parameters. Tel Aviv: Israel Society of Clinical Pediatrics, 2010
7. Leeds JS, Hopper AD, Hadjivassiliou M, Tesfaye S, Sanders DS. High prevalence of microvascular complications in adults with type 1 diabetes and newly diagnosed celiac disease. Diabetes Care 2011; 34: 2158-2163
8. Hansen D, Brock-Jacobsen B, Lund E, et al. Clinical benefit of a gluten-free diet in type 1 diabetic children with screening-detected celiac disease: a population-based screening study with 2 years’ follow-up. Diabetes Care 2006; 29: 2452-2456
9. Mohn A, Cerruto M, Iafusco D, et al. Celiac disease in children and adolescents with type I diabetes: importance of hypoglycemia. J Pediatr Gastroenterol Nutr 2001; 32: 37-4
10. Mollazadegan K, Kugelberg M, Montgomery SM, et al. population-based study of the risk of diabetic retinopathy in patients with type 1 diabetes and celiac disease. Diabetes Care 2013; 36: 316-321
11. Pitocco D, Giubilato S, Martini F, et al. Combined atherogenic effects of celiac disease and type 1 diabetes mellitus. Atherosclerosis 2011; 217: 531-535
12. Mollazadegan K, Sanders DS, Ludvigsson J, Ludvigsson JF. Long-term coeliac disease influences risk of death in patients with type 1 diabetes. J Intern Med 2013; 274: 273-280
13. Fry L, Seah PP, Harper PG et al.The small intestine in dermatitis herpetiformis. J Clin Pathol 1974; 27:817-24
14. Fry L. Leonard JN, Swain F et al. Long term follow up of dermatitis herpetiformis with and without dietary gluten withdrawal. Br J Dermatol 1982; 107:631-40
15. Fry L, Seah PP, Harper PG et al.The small intestine in dermatitis herpetiformis. J Clin Pathol 1974; 27:817-24
16. Fry L. Leonard JN, Swain F et al. Long term follow up of dermatitis herpetiformis with and without dietary gluten withdrawal. Br J Dermatol 1982; 107:631-40