Acute ischemic stroke in young adults: comparative analysis of outcomes and mortality in metabolically healthy obese or overweight vs. non-obese or overweight hospitalizations, 2016-2019 cohort.

Introduction: Rising obesity rates and the increasing prevalence of stroke in the metabolically healthy obese and overweight (MHOO) necessitate examining its association in younger (18-44 year) populations and analyzing acute ischemic stroke (AIS) trends and outcomes in MHOO vs. metabolically healthy non-obese or overweight (MHnOO).

Methods: Data from the United States National Inpatient Sample (2016-2019) was analyzed to identify young MHOO and MHnOO AIS patients using ICD-10-CM codes. Metabolically healthy status was defined by excluding hospitalization records with diagnostic codes for hypertension, diabetes, and dyslipidemia. Demographics, trends, and outcomes were compared using appropriate statistical approaches.

Results: Of 26,949,310 young metabolically healthy hospitalizations between 2016 and 2019, 47,795 had AIS, of which 4,985 were MHOO and 42,810 were MHnOO. The median age of AIS hospitalization was 35 years, and primarily female and white. From 2016 to 2019, AIS incidence rose slightly, which was significant only for the MHnOO cohort. The in-hospital mortality rate was significantly lower in the MHOO cohort (6.0 % vs. 8.6 %, p < 0.001). Hospitalization length and cost did not differ substantially between groups. Adjusted multivariable analysis revealed no significant difference in AIS hospitalization risk between MHOO and MHnOO (aOR: 1.02, p=0.701), with subgroup analysis in males (aOR: 0.88, p=0.161) or females (aOR: 1.06, p=0.363). However, all-cause in-hospital mortality (ACIHM) in AIS had lower odds in the MHOO vs. MHnOO cohorts (aOR: 0.60, p=0.021).

Conclusion: Our study finds a rising trend of AIS hospitalizations in young metabolically healthy adults, with obesity or overweight status not being associated with AIS hospitalization. We identify an "obesity paradox" of lower odds for ACIHM for AIS hospitalizations in the MHOO cohort.