To the Editor: Dr Whitmer and colleagues1 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%.
Graveling AJ, Frier BM. Dementia and Hypoglycemic Episodes in Patients With Type 2 Diabetes Mellitus. JAMA. 2009;302(8):843-844. doi:10.1001/jama.2009.1205