Biomarkers of basic activities of daily living in Alzheimer's disease.

Functional impairment is common in Alzheimer's disease (AD) and related to increased caregiver burden and institutionalization. There is a dearth of research investigating the relationship between specific biomarkers and basic activities of daily living (BADLs) such as toileting, feeding, dressing, grooming, bathing, and ambulating. The present study examined the relationship between serum based biomarkers and specific ADLs in a sample of AD patients. Data were collected from 196 participants enrolled in the Texas Alzheimer's Research and Care Consortium Project and diagnosed with AD. BADLs were measured using the Lawton-Brody Physical Self-Maintenance Scale. A panel of 22 biomarkers previously found to be related to AD pathology was used for the analysis. Stepwise regression modeling was used to assess the link between the biomarkers and BADLs. Results were also examined by gender. Nine of the 22 biomarkers were significantly related to BADLs. When stratified by gender, the biomarkers accounted for 32% of the variance in the males and 27% in females. The pattern of significant biomarkers differed by gender with IL 7 and Tenascin C significantly related to BADLs for females and IL 15 significantly related to BADLs for males. The results of this study indicated that a small number of serum based biomarkers are related to BADLs, and these biomarkers differed by gender.