Lipscombe et al1 reported on elderly subjects with preexisting diabetes mellitus (DM) drawn from a Canadian population-derived health database. Their finding that the risk of hospitalization for hyperglycemia was 8 to 15 times higher in subjects recently (only 1 prescription within the period overlapping the index hospitalization) receiving antipsychotic drugs (APDs) than in those not receiving APD during the 6 months before the index date should be interpreted with caution. Starting therapy with APDs in elderly subjects is usually for neuropsychiatric and behavioral problems of dementia rather than schizophrenia or affective psychosis. This most likely was the reason in this sample, given the large number of patients with dementia. The cognitive and/or behavioral deterioration would have adversely effected the individuals' treatment compliance, putting them at risk for hyperglycemia. Hyperglycemia by itself is associated with cognitive deterioration.2 At least in some individuals, hyperglycemia-induced delirium-like presentation might have prompted the initiation of APD therapy, with the patient subsequently being hospitalized for hyperglycemia within a short period.
Hasnain M, Vieweg WVR. Antipsychotic Drug–Associated Acute Hyperglycemia in Elderly Diabetic Patients: Do the Drugs Explain the Hyperglycemia?. Arch Intern Med. 2009;169(22):2162-2166. doi:10.1001/archinternmed.2009.448