Abstract
INTRODUCTION: Acute ischemic stroke is a major cause of global mortality and disability. This study aimed to investigate the association between mean corpuscular volume (MCV) and 3-month outcomes in acute ischemic stroke patients. METHODS: This study is a secondary analysis based on a prospective cohort study conducted at a single center in Korea from January 2010 to December 2016. The study included 1,906 acute ischemic stroke patients. The exposure variable was MCV measured within 24 hours of admission, and the outcome variable was the modified Rankin Scale (mRS) score at 3 months post-admission. Covariates included age, gender, body mass index, hemoglobin, hematocrit, liver function indicators, diabetes history, and stroke etiology. RESULTS: Piecewise linear regression analysis revealed a non-linear U‑shaped association of MCV on adverse outcomes, with a critical turning point at 92.1 fl. After full adjustment (Model 3), when MCV was below 92.1 fL, each 1 fL increase was associated with an 8% lower odds of poor 3-month outcome (OR = 0.92, 95% CI: 0.88-0.96, p = 0.0003). Conversely, when MCV exceeded 92.1 fL, each 1 fL increase was associated with a 4% higher odds of poor outcome (OR = 1.04, 95% CI: 1.00-1.08, p = 0.0391). CONCLUSION: There was a U‑shaped association between MCV and three-month outcome in patients with acute ischemic stroke.