Huizhen Lu, Chuanliu Wang, Ming Yang, Yuanshao Lin, Weifeng Jiang
Background The monocyte-to-albumin ratio (MAR) integrates systemic inflammation and nutritional status derived from routine laboratory data. We assessed whether the admission MAR is associated with 3-month functional outcomes following acute ischemic stroke (AIS). Methods We conducted a single-center, retrospective cohort study of consecutive adults with AIS admitted within 3 days of symptom onset (October 2023–March 2024). MAR was calculated from the admission monocyte counts and serum albumin levels. The primary outcome was poor 3-month functional status, defined as a modified Rankin Scale (mRS) score ≥3. Associations between MAR and outcomes were examined using multivariable logistic regression (with and without adjustment), smooth curve fitting, and prespecified subgroup analyses (sex, age, smoking status, drinking status, hypertension, diabetes status, eGFR, and TOAST subtype). Results Among 395 patients (mean age 66.2 years; 34.7% female), 59 (14.9%) had poor outcomes. A higher admission MAR independently predicted poor outcomes: per 1-unit increase, the adjusted odds ratio (OR) was 1.13 (95% CI 1.07–1.20; p < 0.001). Compared with the low tertile, patients with the high tertile had significantly greater odds (OR 3.21; 95% CI 1.25–8.20) with a linear trend ( P for trend = 0.006). Smooth curve fitting demonstrated a largely monotonic increase in risk across the observed MAR range. Associations were consistent across subgroups with no significant interactions (all interactions p > 0.05). With respect to the TOAST subtype, the MAR remained significant for large-artery atherosclerosis (OR 1.10; 95% CI 1.02–1.20) and small-artery occlusion (OR 1.23; 95% CI 1.07–1.42), but not for cardioembolism. Conclusion The admission MAR is independently and positively associated with poor 3-month functional outcomes after AIS. MAR is a promising tool for early risk assessment when it is integrated with established predictors.