China Alzheimer's Disease and Neurodegenerative Disorder Research (CANDOR) -A Prospective Cohort Study for Alzheimer's Disease and Vascular Cognitive Impairment.

Background: Alzheimer's disease (AD) and vascular cognitive impairment (VCI) are the two main causes of dementia. AD and VCI share similar symptoms of cognitive decline and may be attributable to similar risk factors. Establishing a prospective cohort to compare VCI and AD would help to understand vascular risk factors related to dementia.

Objectives: China Alzheimer's disease and Neurodegenerative Disorder Research (CANDOR) study is a prospective multicenter cohort study. It aims to study the similarities and differences between AD and post stroke cognitive impairment (PSCI) in neuroimaging changes, disease progression, and multiple omics studies.

Design: This is an ongoing study. From July 31, 2019, to August 1, 2022, we recruited 1449 participants with ages between 40 and 100 years. The cohort included three groups: AD group, PSCI group, and normal cognitive (NC) group. Data were collected in face-to-face interviews at baseline, and will be followed up every year for 4 years. The PSCI group had additional follow-ups at 3-month and 6-month after enrollment. Brain Magnetic Resonance Imaging (MRI) included high-resolution sequences for intracranial arteries. Cognitive assessments and follow-up information will be prospectively collected. Biological specimens including blood and urine at baseline were collected and tested.

Participants: The targeted sample size of PSCI group was 500, AD group with 600 and NC group with 2000. There were 1449 participants enrolled. Include 508 participants were in NC group, 387 in AD group and 554 in PSCI group.

Measurements: Demographics, clinical parameters, and medical examinations were collected and performed. Cognitive assessment was performed to assess all cognitive domains including memory, language, executive function, and orientation function.

Conclusions: The CANDOR study is a prospective cohort study. Data from this cohort provide us an opportunity to investigate the contribution of vascular factors to dementia pathogenesis.