Body Mass Index and Acute Ischemic Stroke Outcomes

Background The impact of body mass index on acute ischemic stroke outcomes is unclear. Aims and/or hypothesis We sought to determine the effect of body mass index on short-term (90 days) acute ischemic stroke outcomes. Methods Data were extracted for patients with acute ischemic stroke and records of body mass index at baseline from the Virtual International Stroke Trials Archive database. Multivariate logistic regression and Cox proportional hazard analysis were used to analyze effect of body mass index on poor functional outcome (modified Rankin Scale >2) and mortality, respectively, within 90 days of stroke's onset. Results Of the 4811 patients (mean age 68·8 ± 12·2 years) included in the study, 2002 (41·6%) were overweight, and 1095 (22·8%) were obese. Overweight (body mass index 25-29·9 kg/m2) was associated with decreased mortality (hazard ratios 0·59; 95% confidence interval 0·51-0·68; P < 0·01) and decrease in poor functional outcome (odds ratio 0·74; 95% confidence interval 0·64-0·85; P < 0·01) following acute ischemic stroke. The association of body mass index with stroke outcomes was dependent on age, gender, and use of thrombolytic therapy. Conclusions Being overweight or obese is associated with a better functional outcome and reduced mortality in patients of acute ischemic stroke. However, the definition of an 'optimal' body mass index, in relation to stroke outcomes, may be affected by age, gender, and use of thrombolytic therapy.