Frailty in early Alzheimer's disease: Complementary clinical value and prognostic significance in biomarker-defined mild cognitive impairment due to Alzheimer's disease.

Frailty, reflecting diminished physiological reserve, may influence how Alzheimer's disease (AD) pathology manifests. This study evaluated the prognostic relevance of frailty in mild cognitive impairment due to AD (MCI-AD). 50 patients underwent frailty assessment using the Clinical Frailty Scale (CFS), with multimorbidity, polypharmacy, and cognition (Mini-Mental State Examination, MMSE) recorded. Participants (median age 74 years; 76% women) exhibited low frailty (median CFS 3). Higher CFS scores correlated with lower baseline MMSE and faster annual decline. In adjusted analyses, CFS independently predicted both poorer cognition and steeper decline, whereas CSF P-tau did not. Frailty thus provides complementary prognostic information to biomarkers in the early stages of AD.