14th September 2024

Diagnosis

T1DM is diagnosed when persistent hyperglycaemia (random plasma glucose > 11 mmol/L) is observed, caused by absolute insulin deficiency, a family history, and other symptoms traditionally associated with diabetes, such as fatigue, polyuria, polydipsia, and rapid weight loss. Older adults may present atypically. Diagnosis is confirmed by measuring C-peptide levels and/or diabetes-specific antibody titres.

Numerous antibodies are associated with a higher risk of developing T1DM, although their presence is not part of the diagnostic criteria. These autoantibodies include islet cell antibodies (ICA), glutamic acid decarboxylase (GAD), islet tyrosine phosphatase (IA-2), and zinc transporter 8 (ZnT8).