Ebetsu Active Future Study (EAFS): cognitive function and physical and mental health in elderly residents of Ebetsu City, Japan - cohort profile.

PURPOSE: Ebetsu Active Future Study (EAFS) conducts comprehensive annual surveys of individuals who are independent in activities of daily living (ADLs) to track age-related physical and mental changes. These surveys include a variety of assessments such as cognitive function tests, physical function tests, blood tests, self-administered questionnaires about lifestyle and health, and interviews regarding medical and family history. In addition, serum, plasma and DNA samples from these assessments are stored at -80°C to facilitate future analyses and accommodate the potential addition of new measurement items. The purposes of this study are: (1) to identify potential blood-based biomarkers applicable to the detection of various types of mild cognitive impairment (MCI), (2) to explore diet-based strategies for preventing MCI and the progression of dementia, (3) to examine the relationship between urban characteristics, individual attributes and healthy life expectancy in Ebetsu City and (4) to return the research findings to the city.

PARTICIPANTS

From August to October 2023, EAFS invited Ebetsu residents to participate in the study. As a result, 1340 individuals applied and 1189 residents aged between 55 and 75 years who were independent in ADLs participated in the baseline survey for the first year.

FINDINGS TO DATE: EAFS initiated a follow-up of 1189 participants (38.9% male; 64.5±5.6 years) in the baseline year of 2023 and maintained a high follow-up rate of 98.5% by wave 3 (2025). The Montreal Cognitive Assessment-Japanese demonstrated that 53.6% of the participants had operational MCI. The proportion of participants with operational MCI increased with ageing. Regarding the APOE4 gene, which is associated with an increased risk of Alzheimer's disease, 1.2% of the total population were homozygous carriers and 22.1% were heterozygous carriers.

FUTURE PLANS: EAFS will conduct annual follow-up surveys until 2032. In addition to analysing data for each objective, we also plan to perform further analysis of the stored specimens.