Low Body Mass Index Increases Frailty Risk in Old–Old Adults: Findings From a 3‐Year Longitudinal Study

OBJECTIVES: Frailty risk increases with age. It is important to understand how body mass index (BMI) relates to changes in frailty risk among adults aged 75 years and older (old-old adults). We examined the longitudinal association between baseline BMI and changes in frailty risk over 3 years. METHODS: . Frailty risk was assessed using the Old-Old Questionnaire for Medical Checkups, a validated tool for assessing multidimensional frailty. Thirteen items were analyzed, excluding smoking and social support domains, to better examine the association between BMI and frailty risk. Higher scores indicate a greater frailty risk. We used linear mixed-effects models to analyze the associations between BMI categories at baseline and changes in frailty risk. RESULTS: group (β = -0.01, Standard error = 0.06, p = 0.821). CONCLUSION: experienced a more pronounced increase in frailty risk over the 3-year follow-up period.