This study aims to screen and diagnose coeliac disease in patients with type 2 diabetes and monitor the effect of gluten-free diet on the metabolic status

Coeliac Disease (CD) is a chronic disease with long-term consequences if untreated . CD has been traditionally associated with autoimmune disorders as type 1 Diabetes . However, recent data suggest association with insulin resistance, metabolic syndrome and type 2 diabetes . In a recent study comparing prevalence of autoimmune markers in type 1 diabetes versus type 2, coeliac disease serologic markers were 5% versus 8.7% respectively . In a study published at Nature communication, a genetic link between Ig A levels, type 2 diabetes, and coeliac disease was found . Gluten, among other factors, is thought to play a proinflammatory role exaggerating the damage to β-cells in both type 1 and type 2 diabetes . Presentation of coeliac disease is very variable, ranging from asymptomatic, gastrointestinal symptoms, atypical symptoms, to malabsorption syndrome. Our interest of the very wide atypical presentations is poorly controlled type 2 diabetes . Moreover, it has been recently suggested that gluten-free diet improves glucose metabolism . Screening and diagnosing coeliac disease remain a highly controversial topic, especially in individuals with atypical or no symptoms. A lifelong gluten avoidance can be only justified by a solid diagnosis, achieved by histopathological diagnosis. Intestinal biopsy is invasive test with not that-accurate results. The new guidelines confirmed the accuracy of the no-biopsy approach, only in case of high-titre positive two antibody tests, as published by the European Society Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHN) . However, guidelines intended for adults still insist on biopsy for confirming final diagnosis . The only exception is the interim guidance during Corona Virus -19 ( COVID-19 ) allowing non-biopsy diagnosis with two separate serology tests . However, recent retrospective study confirmed that high titre tTG had more than 95% diagnostic rate, and duodenal biopsy was not needed . For screening, many approaches have been studied, with measuring total immunoglobulin A (IgA) and IgA tissue transglutaminase (tTG) is the obvious first choice. However, for resource-deficient economies, rapid easy cheap point-of-care tests for deamidated gliadin antibodies (DGP) have been suggested .

Inclusion Criteria:

1. adult patients ≥18 years old
2. diagnosed with type 2 diabetes mellitus

Exclusion Criteria:

1. Patients already diagnosed with co-morbid autoimmune disorder
2. patient diagnosed as systemic lupus
3. diagnosed as rheumatoid arthritis
4. already diagnosed with coeliac disease

All Diabetic type 2 willing participants, after obtaining informed consent, will be subjected to full history taking, thorough clinical examination and total immunoglobulin A (IgA) and IgA tissue transglutaminase antibody (tTG-Ab). -Those with IgA deficiency or positive tTG-Ab are offered upper endoscopy for confirmation by duodenal biopsy. -Those with confirmed Coeliac Disease will be given detailed dietary advice and promoted to strictly adhere to gluten-free diet