- Among patients aged ≥65 years with insulin-treated type 2 diabetes (T2D), the relationship between HbA1c and mortality is U-shaped.
Why this matters
- Recent guidelines call for individualized HbA1c targets for patients with T2D.
- Data analyzed for 4589 insulin-treated adults aged ≥65 years from 532 UK General Practices via the Health Improvement Network database.
- Funding: None disclosed.
- Over median follow-up of 3.6 years:
- 1445 deaths from all causes (56/1000 person-years), and
- 982 composite events of nonfatal myocardial infarction and stroke.
- In adjusted model, all-cause mortality was highest in (HRs):
- Lowest HbA1c category (
- Highest HbA1c category (≥11.5%): 1.40 (P=.039).
- The U-shaped relationship was not seen for the 2-point composite cardiovascular endpoint, with increased risk vs 6.5%-7.4% group seen only in the
- Compared with the 6.5%-7.4% HbA1c group, risk for composite cardiovascular events was higher by:
- 4% with HbA1c 7.5%-8.4%;
- 2% with 9.5%-10.4%;
- 12% with 10.5%-11.4%; and
- 13% with ≥11.5%.
- Observational study, missing data.
- Data from prescriptions, not adherence.
- Factors other than HbA1c may influence insulin intensification decisions.
- Potential unmeasured confounding, e.g., relationship of risk factors and outcomes.