Abstract WP305: Impact Of Metformin on Survival Following Ischemic Stroke in Patients With Diabetes: The Greater Cincinnati Northern/Kentucky Stroke Study (GCNKSS)

Abstract

Introduction: Metformin, an oral antidiabetic drug, is associated with reduced risk of diabetic related endpoints, including stroke. Evidence from animal studies show neuroprotective properties of metformin via the AMP-activated protein kinase pathway. We examined if these neuroprotective effects of metformin may extend into improved survival among stroke patients. Methods: All stroke patients within the Greater Cincinnati/Northern Kentucky catchment area of ∼ 1.3 million were identified using ICD-9 discharge codes (430-436) in 2005 and 2010. Cases were abstracted by study nurses and verified by physician review. Patients surviving to hospital discharge with a history of diabetes or diagnosed with diabetes during hospitalization (DM) were categorized into four groups based on recorded medication use: metformin monotherapy, metformin combotherapy, other antidiabetic drug therapy, and no antidiabetic medications. The primary outcome was all cause case fatality at 3 years following stroke. Covariates considered were age at onset, sex, race, BMI, baseline NIHSS and mRS, smoking status, history of comorbidities, and glucose level on admission. Cox proportional hazard models were used to estimate the risk of case fatality. Results: Overall, 37% (1,471) of the 4,015 ischemic stroke patients (>= 20 years of age) met criteria for DM. Patients with DM (vs non DM) were 65 (vs 66) years of age, 55% (vs 56%) female, and 27% (vs 18%) black. Of patients with DM, 10% were on metformin monotherapy, 28% metformin combotherapy, 50% other antidiabetic drugs, and 13% no antidiabetic drugs. In adjusted analysis, at 3 years post stroke, patients on metformin monotherapy or combotherapy had similar risk of case fatality compared with non-DM and had lower risk of case fatality compared with DM on no drug therapy (Table). Conclusions: Use of metformin, either alone or in combination with other antidiabetic drugs may provide a long term survival benefit among stroke patients with diabetes.