Prevalence of Diabetes-related Autoantibodies Among Individuals With Type 2 Diabetes From Primary Care and Endocrinology Community Practice Settings.

Objective: The full implications of diabetes-related autoantibodies for classification and management of type 2 diabetes remain undetermined. To date, there are limited data on autoantibody positivity in community-based samples in the United States. This study assessed and compared the prevalence of diabetes-related autoantibodies in a community-based population of individuals with type 2 diabetes managed by endocrinology or primary care providers (PCPs).

Methods: This single-center cross-sectional study enrolled 202 adults (102 in endocrinology and 100 in PCPs) with type 2 diabetes without a history of latent autoimmune diabetes of adulthood. Glutamic acid decarboyxlase-65, anti-islet cell, insulinoma-associated-2, zinc transporter 8, and anti-insulin antibodies were determined.

Results: Among 199 participants with full antibody panel testing results, 13.6% tested positive for at least one diabetes-related autoantibody; prevalence trended higher, but nonsignificantly, among individuals managed by endocrinologists (16.0%) vs PCPs (11.1%). GAD-65 positivity was 4.5%. No participants displayed anti-islet cell autoantibodies. After excluding an additional 12 individuals positive for only anti-insulin antibodies, 8.0% of the remaining participants were autoantibody-positive (median age, 71 years; median body mass index, 31.8 kg/m²).

Conclusions: The prevalence of diabetes-related autoantibodies in individuals with type 2 diabetes in a U.S. community-based care setting, most of whom did not display LADA phenotype characteristics, was notable and similar regardless of management by endocrinology or PCP practices. Although further studies are needed to assess the clinical implications of these findings, it is possible that proactive awareness of autoantibody status in individuals with type 2 diabetes could provide additional context to help guide treatment decisions.