Exploring the relationship between cognitive function and frailty in middle-aged and older adults Chinese adults: evidence from the CHARLS database

Background Frailty is a complex age-related clinical syndrome characterized by diminished physiological reserve and increased vulnerability to stressors. Cognitive function may be associated with frailty; however, evidence from nationally representative Chinese populations remains limited. Methods This cross-sectional study utilized data from the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative survey of individuals aged 45 and older. Cognitive function was assessed using the Mini-Mental State Examination (MMSE), and frailty was evaluated using the Physical Frailty Phenotype (PFP). Data from 19,307 participants were analyzed using logistic regression, Lasso regression, and overlap weighting methods to control for confounding factors. Subgroup analyses by age and gender were conducted to examine variations in the association between cognitive function and frailty. Results Among the participants, 13.49% were assessed as having cognitive impairment, and 3.53% were identified as frail. Logistic regression showed that cognitive impairment was associated with a 146% increased risk of frailty (OR: 2.46, 95% CI: 2.15–2.83). Subgroup analysis revealed a stronger association in individuals over 60 years old (OR: 3.35, 95% CI: 2.23–5.06) and in women (OR: 3.25, 95% CI: 1.84–5.74) compared to men (OR: 2.56, 95% CI: 2.03–3.26). Sensitivity analyses confirmed the robustness of these findings. Conclusion Cognitive impairment is significantly associated with an increased risk of frailty, particularly in older adults and women. These findings suggest that cognitive decline is associated with higher frailty risk, and this association may be explained by physiological, psychological, and social factors. Future longitudinal and intervention studies are needed to determine whether addressing cognitive impairment can reduce frailty risk and improve health outcomes in aging populations, particularly in vulnerable subgroups.