Coexistence of low body mass index and poor oral health negatively affects activities of daily living, swallowing, and cognition after stroke

Aim Low body mass index (BMI) and poor oral health are prevalent among older stroke patients and associated with adverse outcomes. However, their combined impact on functional recovery after stroke remains unclear. This study investigated the synergistic effects of low BMI and poor oral health on activities of daily living (ADL) independence, swallowing function, and cognitive status in post‐stroke older patients. Methods A retrospective cohort study was conducted on 708 hospitalized post‐stroke patients aged ≥70 years. Low BMI was defined as 78) at discharge. Secondary outcomes included swallowing level (Food Intake Level Scale) and cognitive status (Functional Independence Measure‐cognition score). Multiple regression analyses were performed to examine the associations of low BMI, poor oral health, and their combination with outcomes of interest. Results The coexistence of low BMI and poor oral health was independently associated with lower odds of achieving ADL independence (odds ratio 0.130, 95% confidence interval CI 0.023–0.718), worse swallowing level (B = −0.878, 95% CI −1.280 to −0.476), and poorer cognitive status (B = −1.872, 95% CI −2.960 to −0.784) at discharge, after adjusting for confounders. The combined impact was stronger than either condition alone. Conclusions The coexistence of low BMI and poor oral health exerts a synergistic negative impact on functional recovery in older stroke inpatients. Comprehensive interventions integrating nutritional support, oral management, and rehabilitation are crucial to optimizing outcomes in this vulnerable population. Geriatr Gerontol Int 2024; 00: 000–000. Geriatr Gerontol Int 2024; ••: ••–•• .