The Effects of Body Mass Index on In-hospital mortality following first ischemic or hemorrhagic stroke events: Does the obesity paradox apply?

Background: While it is widely held that obesity is a risk factor for stroke, its role in mortality after stroke is less understood. We aim to examine effects of Body Mass Index (BMI) on in-hospital mortality after non-subarachnoid, subarachnoid, and ischemic stroke. Methods: Retrospective cohort study. Patients aged >= 18 years, who were hospitalized in Florida hospitals between 2008 and 2012 with a diagnosis of first-time stroke as reported by the Agency for Health Care Administration (AHCA). The main independent variable was BMI category, which was divided into non-overweight/non-obese, obese, and morbidly obese. The primary outcome was the adjusted odds ratio (aOR) for in-hospital mortality for subarachnoid and non-subarachnoid hemorrhagic stroke, and ischemic stroke. Logistic regression modeling was utilized to examine the association between each BMI category and in-hospital mortality, while controlling for several potential confounders. This study was reported in line with the STROCSS criteria. Results: Of the 333,367 patients included in the database, 150,153 (45.0%) patients met inclusion criteria. After adjusting for age, gender, ethnicity and other possible confounders, obese patients were 21% less likely to die during their hospitalization following a first ischemic stroke (0.79 aOR, 0.69-0.92, 95% CI, p = 0.002), and 32% less likely following a first non-subarachnoid hemorrhage (0.68 aOR, 0.57-0.82, 95% CI, p = 0.0001) compared to non-overweight/non-obese counterparts. Conclusion: Obese patients are less likely to die during hospitalization following first-time non-subarachnoid hemorrhage and ischemic stroke than non-overweight/non-obese patients. These findings support the obesity paradox concept, though more research is needed for recurrent stroke patients.

Automated summary

This study found that obese patients are less likely to die during hospitalization following first-time non-subarachnoid hemorrhage and ischemic stroke compared to non-overweight/non-obese patients.