There is lack of information on the risk factors of accelerated cognitive decline in older people with Alzheimer disease (AD). The extent of neurodegeneration and white matter disease has been reported to be important factors. In addition there may be biomarkers e.g. inflammatory cytokines that can contribute to cognitive decline. The impact of care arrangement and physical activity may also be important. Insulin signaling is impaired in Alzheimer disease (AD).

We therefore propose to perform a cohort study of older people with AD. This will be based on an on-going AD registry which was designed to identify genetic biomarkers for AD. Detailed neurocognitive tests and lifestyle information are available. In addition, volumetric MRI brain scans were performed in all AD subjects. The hypothesis is that MRI brain volumes, serum biomarkers, physical activity, physical functioning are independently associated with cognitive decline in older people with AD. The objective is to identify risk factors of accelerated cognitive decline so that preventive measures can be designed to delay dependency in AD.

Inclusion Criteria:

• Sufficient Cantonese competency for cognitive test
• Clinical diagnosis of AD
• FAST test staging 3-5

Exclusion Criteria:

• Subjects who refuse blood taking procedure
• No reliable family caregiver informant (person contact at least once a month)

Subjects are recruited from the geriatric outpatient clinics or memory clinic.