Prevalence of Positivity for Diabetes-Associated Autoantibodies in Individuals with Type 2 Diabetes and Their Further Characterisation: Cross-sectional Study from Slovakia

Mariana Rončáková; Arash Davani; Veronika Mikušová; Ivana Ságová; Peter Novodvorský; Emil Martinka

doi:10.1007/s13300-023-01440-2

Prevalence of Positivity for Diabetes-Associated Autoantibodies in Individuals with Type 2 Diabetes and Their Further Characterisation: Cross-sectional Study from Slovakia

Diabetes Ther. 2023 Sep;14(9):1537-1548. doi: 10.1007/s13300-023-01440-2. Epub 2023 Jul 8.

Authors

Mariana Rončáková^{1

2}, Arash Davani¹, Veronika Mikušová^{1

3}, Ivana Ságová^{1

2}, Peter Novodvorský^#^{4

5}, Emil Martinka^#⁶

Affiliations

¹ National Institute of Endocrinology and Diabetology, Ľubochňa, Slovakia.
² Jessenius Faculty of Medicine in Martin, Comenius University, Bratislava, Slovakia.
³ First Department of Medicine, University Hospital Martin, Martin, Slovakia.
⁴ Diabetes Centre, Institute for Clinical and Experimental Medicine (IKEM), Prague, Czech Republic.
⁵ Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK.
⁶ National Institute of Endocrinology and Diabetology, Ľubochňa, Slovakia. martinka@nedu.sk.

^# Contributed equally.

Abstract

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.

Keywords: Antibody against glutamic acid decarboxylase (anti-GAD65); Antibody against insulin (IAA); Antibody against insulinoma-associated antigen IA-2 (IA-2A); Diabetes-associated autoantibodies (DAA); Latent autoimmune diabetes of adults (LADA); Type 2 diabetes mellitus (T2D).