Autoimmunity behind the mask: identifying latent autoimmune diabetes among adults diagnosed with type 2 diabetes

Muhammad Zeeshan; Aoife O; Khadija Sharif; Wasif Raza; Nisar A. Khan; Aidah Ilyas; Bellinda Mitchell; Muhammad A Janjua; Lucy Phelan; Farooq Khan; Ihtisham Malik

doi:10.1530/endoabs.115.P16

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Endocrine Abstracts (2026) 115 P16 | DOI: 10.1530/endoabs.115.P16

IES2025 Research, Audit and Quality Improvement Projects Physical Posters (55 abstracts)

Autoimmunity behind the mask: identifying latent autoimmune diabetes among adults diagnosed with type 2 diabetes

Muhammad Zeeshan , Aoife O’Connor , Khadija Sharif , Wasif Raza , Nisar A. Khan , Aidah Ilyas , Bellinda Mitchell , Muhammad A Janjua , Lucy Phelan , Farooq Khan & Ihtisham Malik

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St Luke’s General Hospital, Kilkenny, Ireland

Background: Latent Autoimmune Diabetes in Adults (LADA) is frequently misclassified as type 2 diabetes mellitus (T2DM), leading to delayed insulin initiation and suboptimal outcomes. International guidelines recommend autoantibody and C-peptide testing in adults with atypical diabetes to guide accurate diagnosis and treatment.

Methods: We retrospectively reviewed adults diagnosed with diabetes at St Luke’s General Hospital between January 2022 and December 2024. Using the Cellma electronic health record, we analysed demographics, initial classification, glutamic acid decarboxylase (GAD) antibody status, C-peptide levels, treatment changes, and HbA1c outcomes. Statistical analyses included independent t-tests for C-peptide comparisons and Fisher’s exact test for HbA1c improvement.

Results: Of 200 adults with diabetes, 143 (71.5%) were initially classified as T2DM. GAD antibody testing was performed in 116/143 (81.1%), with 16 (13.8%) positive, confirming LADA. Mean C-peptide was significantly lower in LADA patients (0.39 nmol/l) than in GAD-negative T2DM patients (0.97 nmol/l, P < 0.001). Following reclassification, 14/16 LADA patients commenced insulin therapy; all demonstrated significant HbA1c improvement (P = 0.003). Two patients were awaiting clinical review.

Conclusion: Over one in eight adults initially diagnosed with T2DM in our cohort had LADA. Routine C-peptide and antibody testing in atypical diabetes presentations facilitates early reclassification and targeted therapy, improving glycemic control and potentially preventing complications. Incorporating this diagnostic approach into standard clinical pathways is essential for optimizing diabetes care.