Autoimmunity plays a role in the onset of diabetes after 40 years of age
Creators: name: Rolandsson, Olov
name: Hampe, Christiane S.
name: Sharp, Stephen J.
name: Ardanaz, Eva
name: Boeing, Heiner
name: Fagherazzi, Guy
name: Mancini, Francesca Romana
name: Nilsson, Peter M.
name: Overvad, Kim
name: Chirlaque, Maria-Dolores
name: Dorronsoro, Miren
name: Gunter, Marc J.
name: Kaaks, Rudolf
name: Key, Timothy J.
name: Khaw, Kay-Tee
name: Krogh, Vittorio
name: Kühn, Tilman
name: Palli, Domenico
name: Panico, Salvatore
name: Sacerdote, Carlotta
name: Sánchez, Maria-José
name: Severi, Gianluca
name: Spijkerman, Annemieke M. W.
name: Tumino, Rosario
name: Van Der Schouw, Yvonne T.
name: Riboli, Elio
name: Forouhi, Nita G.
name: Langenberg, Claudia
name: Wareham, Nicholas J.
Publisher: name: Apollo - University of Cambridge Repository
Year: 2019
Subjects: Article
Autoantibody
Autoimmunity
Genetic risk score
Incident diabetes
Type 1 diabetes
Type 2 diabetes

description: Funder: Umea University
description: Abstract: Aims/hypothesis: Type 1 and type 2 diabetes differ with respect to pathophysiological factors such as beta cell function, insulin resistance and phenotypic appearance, but there may be overlap between the two forms of diabetes. However, there are relatively few prospective studies that have characterised the relationship between autoimmunity and incident diabetes. We investigated associations of antibodies against the 65 kDa isoform of GAD (GAD65) with type 1 diabetes and type 2 diabetes genetic risk scores and incident diabetes in adults in European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct, a case-cohort study nested in the EPIC cohort. Methods: GAD65 antibodies were analysed in EPIC participants (over 40 years of age and free of known diabetes at baseline) by radioligand binding assay in a random subcohort (n = 15,802) and in incident diabetes cases (n = 11,981). Type 1 diabetes and type 2 diabetes genetic risk scores were calculated. Associations between GAD65 antibodies and incident diabetes were estimated using Prentice-weighted Cox regression. Results: GAD65 antibody positivity at baseline was associated with development of diabetes during a median follow-up time of 10.9 years (HR for GAD65 antibody positive vs negative 1.78; 95% CI 1.43, 2.20) after adjustment for sex, centre, physical activity, smoking status and education. The genetic risk score for type 1 diabetes but not type 2 diabetes was associated with GAD65 antibody positivity in both the subcohort (OR per SD genetic risk 1.24; 95% CI 1.03, 1.50) and incident cases (OR 1.97; 95% CI 1.72, 2.26) after adjusting for age and sex. The risk of incident diabetes in those in the top tertile of the type 1 diabetes genetic risk score who were also GAD65 antibody positive was 3.23 (95% CI 2.10, 4.97) compared with all other individuals, suggesting that 1.8% of incident diabetes in adults was attributable to this combination of risk factors. Conclusions/interpretation: Our study indicates that incident diabetes in adults has an element of autoimmune aetiology. Thus, there might be a reason to re-evaluate the present subclassification of diabetes in adulthood.