Baseline characteristics in Japan‐multimodal intervention trial for prevention of dementia (J‐MINT) Tamba study

Abstract Background To prevent Alzheimer’s disease, a multimodal intervention has been tried in world wide. J‐MINT is a trial in Japan and is studied in three different areas. J‐MINT Tamba, one of substudies of J‐MINT, has begun in September, 2020 in a Japanese rural area (UMIN000041938). The aim of this study is to report the characteristics of participants at the baseline, especially focusing on APOE subtypes and their cognitive functions. Method This study was cross‐sectional design. The inclusion criteria in this study were as follows; 1) Tamba citizen aged 65‐85 at the time of enrollment, 2) 24 or higher in the Mini‐Mental State Examination, and 3) having at least 1 of the following vascular risks (Treating hypertension or having systolic BP >=140 mm Hg or diastolic BP >= 85 mm Hg and treating diabetes or HbA1c >=6.0%). Cognitive functions were evaluated by following tests; the Trail Making Test (TMT) part A and part B, forward digit span, backward digit span, the Digit Symbol Substitution Test (DSST), the logical memory test from WMS‐R (immediate and delayed recall), and the Free and Cued Selective Reminding Test (FCSRT). The APOE epsilon 4 carrier or noncarrier were identified by serum blood test. Additionally, life‐related factors and number of drug use and type were assessed by self‐reported questionnaire. We performed statistical analyses using multiple regression, with each cognitive function as the dependent variables, the APOE epsilon 4 carrier and the other factors (and interaction) as the independent variable, and age and sex as confounding variables. Result Total 203 elderly were registered (mean age: 73.9 ± 4.8 years, females: 71.4%). The number of participants of APOE epsilon 4 carrier were 18.6% and that of participants with polypharmacy were 35.8%. Although the cognitive functions were not related with the APOE epsilon 4 carrier, TMT part A and DSST were observed the interaction between the APOE epsilon 4 carrier and polypharmacy (coefficient: 16.2, p values < 0.01; ‐10.1, 0.03). Conclusion Coexistence of APOE epsilon 4 and polypharmacy showed lower cognitive functions in spite of the community‐dwelling elderly with normal cognition. These elderlies might develop cognitive decline in early phase.