- Patients with type 1 diabetes (T1D) onset after age 30 years are often diagnosed and treated as having type 2 diabetes (T2D).
- Clinical characteristics do not always predict type.
Why this matters
- Misdiagnosis may delay appropriate insulin therapy.
- UK diabetes research population characteristics assessed for those requiring insulin within 3 years of diagnosis and severe endogenous insulin deficiency (nonfasting C-peptide 30 years.
- Comparison with those with retained endogenous insulin secretion (>600 pmol/L) and 220 with severe insulin deficiency diagnosed at age
- Funding: Wellcome Trust; Exeter.
- Severe insulin deficiency found in 21% of 583 diagnosed with diabetes after age 30 years.
- Participants with late-onset T1D more likely to have been diagnosed and treated as having T2D (15% vs 5% oral glucose-lowering drug use; 62% vs 96% insulin at diagnosis; 20% vs 0% self-reported T2D).
- 41% with late-onset T1D had BMI 2, and 28% of those with BMI 2 had T2D.
- Insulin not given at diagnosis in 38% with late-onset T1D; average was 12 months until receiving it.
- Relatively homogeneous, geographically restricted population.
- Self-reported time to insulin, age at diagnosis.