Obesity is an established cardiovascular risk factor. We studied the association between body mass index (BMI) and all-cause mortality after stroke.
A registry started in 2001 with the aim to register all hospitalized stroke patients in Denmark now includes 21,884 patients in whom BMI was recorded. There are five BMI groups: underweight (BMI or = 35). All patients underwent an evaluation including stroke severity, computed tomography, and cardiovascular risk factors. Survival was followed up to 5 years after stroke (median 1.5 years). Independent predictors of death were identified by means of a survival model based on 13,242 individuals with a complete data set.
Compared to normal-weight patients, mortality was lower in overweight [hazard rate (HR) 0.73, 95% CI 0.66-0.81], obese (HR 0.84, 95% CI 0.73-0.98) and severely obese stroke patients (HR 0.84, 95% CI 0.64-1.10), while mortality was higher in underweight patients (HR 1.63, 95% CI 1.41-1.90).
Poststroke mortality is inversely related to BMI: overweight and obese stroke patients have a lower poststroke mortality rate than normal-weight and underweight patients.