Canadian Practice Assessment in Type 2 Diabetes

Abstract

Background: There is increasing evidence linking diabetes and dementia; however, large population-based studies in this area are lacking. Methods: We used administrative health databases to identify a matched cohort of Ontario seniors (age 66 years) with (n¼225 045) and without newly diagnosed diabetes (n¼668 070) between April 1995 and March 2007. Individuals were followed until March 2012 for a new diagnosis of dementia based on a validated algorithm using hospitalization records and physician services claims. Cox proportional hazards modelling was used to compare the incidence of dementia between groups after adjusting for a number of baseline risk factors. Results: From baseline until March 31, 2012, there were 169 114 new cases of dementia diagnosed among members of our cohort. Individuals with diabetes experienced a significantly higher incidence of dementia (156.5 vs. 150.4 per 1000 person years) than those without diabetes; even after adjusting for baseline cardiovascular disease, chronic kidney disease (CKD) and hypertension (adjusted HR 1.20 [1.17 to 1.22] and 1.14 [1.12 to 1.16] among men and women, respectively). Individuals with diabetes who had prior cerebrovascular disease (HR 2.04 [1.89 to 2.21]), peripheral vascular disease (HR 1.46 [1.18 to 1.81]), CKD (HR 1.41 [1.35 to 1.48]) or hospitalizations/emergency department visits for hypoglycemia (HR 1.53 [1.41 to 1.67]) were at greatest risk for dementia (Table 1). Conclusions: Seniors with newly diagnosed diabetes experience an approximately 20% higher risk of developing dementia. Preexisting vascular disease and other comorbidities increase the risk of dementia in the setting of diabetes.