Newly diagnosed type 2 diabetes and risk of dementia: A population-based 7-year follow-up study in Taiwan

Background: Diabetes is associated with an increased risk of developing dementia. However, data on the patients with newly diagnosed type 2 diabetes are limited. Objective: To investigate the relationship between newly diagnosed type 2 diabetes and the risk of developing dementia, ischemic stroke and intracranial hemorrhage after disease diagnosis and the interrelationship between dementia and the stroke events. Method: Data were collected from the National Health Insurance Research Database of Taiwan. The study cohort included 3717 patients newly diagnosed with type 2 diabetes and 37,170 age- and sex-matched comparison patients from the same period. All patients were tracked for 7 years following their index visit in 2000-2001. Result: After adjusting for potential confounders, dementia risk was approximately 63% higher (hazard ratio [HR], 1.63; 95% CI, 1.33-1.99) among newly diagnosed type 2 diabetic patients than among comparison subjects. Newly diagnosed type 2 diabetes also increased the risk of developing ischemic stroke but not intracranial hemorrhage. About 43.6% of diabetic patients who developed dementia also had ischemic stroke during the follow-up period, higher than the rate 29.6% in the comparison group. Conclusion: This study shows that newly diagnosed type 2 diabetes is associated with a 63% higher future risk of dementia during the 7-year follow-up period. The high dementia and ischemic stroke overlap rate in the diabetic study group suggests vascular events play an important role in the pathogenesis of developing dementia. (C) 2012 Elsevier Inc. All rights reserved.