T2DM: dementia risk lower with first-line metformin vs sulfonylureas

  • Scherrer JF & al.
  • Mayo Clin Proc
  • 1 Aug 2019

  • International Clinical Digest
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Takeaway

  • Metformin (Glucophage, others) is associated with a lower risk for dementia than sulfonylureas among patients receiving first-line treatment for type 2 diabetes mellitus (T2DM).

Why this matters

Key results

  • Respective median follow-up times to dementia in Veterans Health Affairs and Kaiser Permanente Washington cohorts:
    • 4.6 and 7.6 years in metformin users.
    • 4.7 and 7.1 years in sulfonylurea users.
  • Compared with sulfonylurea initiation, metformin initiation netted lower risk of dementia in both cohorts:
    • Veterans Health Affairs cohort (adjusted HR, 0.93; 95% CI, 0.87-0.99).
    • Kaiser Permanente Washington cohort (adjusted HR, 0.89; 95% CI, 0.74-1.07).
  • Findings were similar in:
    • Moderator analyses further adjusted for average monthly glycemic burden or hypoglycemic events.
    • Sensitivity analyses allowing mild cognitive impairment to contribute to the dementia outcome.
  • Among patients ≥75 years, dementia risk did not differ significantly between drugs.

Study design

  • Retrospective cohort study with 2 cohorts of patients ≥50 years who were dementia-free at baseline and had not received diabetes medication for 2 years prior to study entry.
  • Participants initiated monotherapy with metformin or a sulfonylurea:
    • 75,187 Veterans Health Affairs patients.
    • 10,866 Kaiser Permanente Washington patients.
  • Main outcome: dementia.
  • Funding: National Institute on Aging.

Limitations

  • Unmeasured, residual confounding.
  • Uncertain generalizability.
  • Dementia ascertained from diagnosis codes.