Exploring the Obesity Paradox in All Subtypes of Intracranial Hemorrhage: A Retrospective Cohort Analysis of 13,000 Patients
Authors: Ng Helen , Huhulea Ellen N. , Jain Ankita , Fortunato Michael , Subah Galadu , Sacknovitz Ariel , Spirollari Eris , Rosenberg Jon B. , Bauerschmidt Andrew , Mayer Stephan A. , Gandhi Chirag D. , Al-Mufti Fawaz 
Published: November 2024

Background/Objectives: Recent studies reveal an “obesity paradox”, suggesting better clinical outcomes after intracranial hemorrhage for obese patients compared to patients with a healthy BMI. While this paradox indicates improved survival rates for obese individuals in stroke cases, it is unknown whether this trend remains true across all forms of intracranial hemorrhage. Therefore, the objective of our study was to investigate the incidence, characteristics, and outcomes of hospitalized obese patients with intracranial hemorrhage. Methods: The National Inpatient Sample (NIS) database was queried for data from 2015 to 2019 to identify adult patients aged 18 years and older with a primary diagnosis of non-traumatic intracranial hemorrhage. Using International Classification of Disease 10th Edition codes, patients were stratified by BMI categories: healthy weight, overweight, class I–II obesity, and class III obesity. The cohorts were examined for demographic characteristics, comorbidities, stroke severity, inpatient complications, interventions, and clinical outcomes, including length of stay (LOS), discharge disposition, and inpatient mortality. Results: Of 41,960 intracranial hemorrhage patients identified, 13,380 (33.0%) also had an obese BMI. Class I–II obese intracranial hemorrhage patients were more likely to be of white race (OR: 1.101, 95% CI: 1.052, 1.152, p < 0.001), less likely to be female (OR: 0.773, 95% CI: 0.740, 0.808, p < 0.001), and more likely to have diabetes mellitus (OR: 1.545, 95% CI: 1.477, 1.616, p < 0.001) and hypertension (OR: 1.828, 95% CI: 1.721, 1.943, p < 0.001) in comparison to healthy-weight patients. In a matched cohort analysis adjusting for demographics and severity, intracranial hemorrhage patients with class I–II obesity had a shorter length of stay (LOS) (OR 0.402, 95% CI: 0.118, 0.705, p < 0.001), reduced inpatient mortality (OR 0.847, 95% CI: 0.798, 0.898, p < 0.001), and more favorable discharge disposition (OR 1.395, 95% CI: 1.321, 1.474, p < 0.001) compared to their healthy-weight counterparts. Furthermore, these patients were less likely to require decompressive hemicraniectomy (OR 0.697, 95% CI: 0.593, 0.820, p < 0.001). Following an analysis of individual ICH subtypes, obese subarachnoid hemorrhage (SAH) patients demonstrated reduced mortality (OR: 0.692, 95% CI: 0.577–0.831, p < 0.001) and LOS (OR: 0.070, 95% CI: 0.466–0.660, p = 0.039), with no differences in discharge disposition. Similarly, intracerebral hemorrhage patients demonstrated reduced mortality (OR: 0.891, 95% CI: 0.827–0.959, p = 0.002) and LOS (OR: 0.480, 95% CI: 0.216–0.743, p < 0.001). Other ICH subtypes showed improved discharge outcomes (OR: 1.504, 95% CI: 1.368–1.654, p < 0.001), along with decreased mortality (OR: 0.805, 95% CI: 0.715–0.907, p < 0.001) and LOS (OR: −10.313, 95% CI: −3.599 to −2.449, p < 0.001). Conclusions: Intracranial hemorrhage patients with class I–II obesity exhibited more favorable clinical outcomes than those who were of a healthy weight or overweight. Despite its association with risk factors contributing to intracranial hemorrhage, class I–II obesity was associated with improved outcomes, lending support to the existence of the obesity paradox in stroke.