Latent Autoimmune Diabetes in Adults

LADA is slowly progressive autoimmune diabetes in adults, with islet autoantibodies and delayed need for insulin.

• Accounts for 2 to 12% of adult onset diabetes.
• Criteria: age over 30, positive islet antibody (GAD65 usually), no insulin requirement for the first 6 months.
• Lies between type 1 and type 2: high GAD titre predicts faster beta cell failure.
• Shares autoimmune associations with type 1 diabetes.

• Adult onset, often lean or only mildly overweight, with less insulin resistance.
• Initial response to oral agents, then failure in months to a few years.
• Weight loss, osmotic symptoms, occasional ketosis.
• Personal or family history of autoimmune disease.

• GAD65 antibodies (add IA-2, ZnT8 if negative).
• C peptide falling over time (below 0.3 nmol/L suggests need for insulin).
• Exclude MODY, pancreatic disease, steroid or drug diabetes.
• Screen for thyroid and coeliac disease, as for type 1.

• Start insulin early when HbA1c is not at target or C peptide is low; basal insulin 0.2 to 0.3 unit/kg then basal bolus.
• Metformin 500 to 2000 mg daily while insulin sparing is possible.
• DPP-4 inhibitors (sitagliptin 100 mg) may preserve beta cell function.
• Avoid sulfonylureas (accelerate beta cell loss). SGLT2 inhibitors carry ketoacidosis risk and are generally avoided.
• GLP 1 agonists can be used with insulin in overweight patients.
• Monitor HbA1c every 3 months, C peptide yearly. Treat complications as in type 1.