Objective: To determine risk of dementia in both patients with type 1 or type 2 diabetes and in individuals without a diagnosis of dementia but with glycosylated hemoglobin, type A1C (HbA1c) of ≥ 6,5% (48 mmol/mol).
Method: In this register- and cohort-based study, we included all incident diabetes cases registered in the National Diabetes Registry in Denmark from January 2000 through December 2012 (n=151,413) and a reference population, adult participants from the Glostrup cohort (n=16,801), the ADDITION Study (n=26,586) and Copenhagen Aging and Midlife Biobank (n=5,408). Using these cohorts, we analyzed if a diagnosis of type 1 or type 2 diabetes in the National Diabetes Registry or HbA1c level of ≥ 6,5% in the cohorts increased risk of dementia in the Danish National Patient Registry or cognitive performance assessed by the Intelligenz-Struktur-Test 2000R.
Results: Both type 1 and type 2 diabetes were associated with increased risk of dementia with the highest risk estimates for dementia diagnosed before age 65. Self-reported diabetes or high HbA1c levels were associated with lower cognitive performance (p=0.004), while high HbA1c was associated with increased risk of dementia in the Glostrup cohort but not in the ADDITION study.
Conclusions: Both type 1 and type 2 diabetes are associated with increased risk of dementia, however results for screening detected high HbA1c were equivocal.
I. Wium-Andersen: None. J. Rungby: None. M. Jørgensen: None. M. Osler: None. M. Wium-Andersen: None.
Jaschafonden; Lundbeck Foundation; Danish Medical Association; Danish Diabetes Association; M.D. Gerhard Linds Grant; Lundbeck Foundation/Novo Nordisk Foundation; Family Hede Nielsen Foundation; Holger Rabitz and Wife Doris Mary, born Phillip’s Memorial Foundation
