Prevalence of positivity for diabetes-associated autoantibodies in individuals with type 2 diabetes and their further characterisation: cross-sectional study from Slovakia

Background Individuals initially diagnosed with type 2 diabetes (T2D) might exhibit positivity for diabetes-associated autoantibodies (DAA +). We investigated the prevalence of DAA positivity in a group of individuals with T2D who were referred to a tertiary diabetes centre within a pre-specified period of time. We aimed to identify characteristics linked with DAA positivity by comparing DAA + individuals with their DAA-negative counterparts.

Methods This was a cross-sectional study into which all T2D patients referred to the National Institute of Endocrinology and Diabetology, Ľubochňa, Slovakia, between 1 January and 30 June 2016 were included. Data on > 70 participants’ characteristics, including antibodies against glutamic acid decarboxylase (anti-GAD65), insulinoma-associated antigen IA-2 (IA-2A) and insulin (IAA), were collected.

Results Six hundred and ninety-two individuals (387, 55.6% female) with a median (range) age of 62 (24–83) years, HbA1c of 8.9 (5.0–15.7)% [74 (31–148 mmol/mol)] and diabetes duration of 13.0 (0–42) years were analysed. One hundred and forty-five (145/692, 21.0%) tested positive for at least one DAA; 136/692 (19.7%) were positive for anti-GAD65, 21/692 (3.0%) were positive for IA-2A and 9/692 (1.3%) were positive for IAA. Only 84.9% of the DAA + individuals aged > 30 years at the time of diabetes diagnosis met the current diagnostic criteria for latent autoimmune diabetes of adults (LADA). DAA + differed from DAA − individuals in multiple characteristics, including the incidence of hypoglycaemia.

Conclusion Several pathological processes linked with distinct types of diabetes can develop in parallel, including insulin resistance and autoimmune insulitis. In this single-centre cross-sectional study from Slovakia, we report a higher than previously published prevalence of DAA positivity in a group of individuals with a formal diagnosis of T2D.