Dementia and Hypoglycemic Episodes in Patients With Type 2 Diabetes Mellitus

To the Editor: Dr Whitmer and colleagues reported a relationship between severe hypoglycemia and incident dementia in a large cohort of older people with type 2 diabetes. Although severe hypoglycemia may cause permanent cognitive impairment, the results of this study should be viewed with caution. It seems unlikely that a single episode of severe neuroglycopenia could increase the risk of dementia by 50%. Premorbid cognitive ability was assessed...