2.1. Study Design and Statement of Ethics
MAY
We performed a randomized, double-blind, placebo-controlled, parallel-group trial in Yamaguchi Prefecture from December 2021 to May 2022. This study was registered in the UMIN-CTR (UMIN00004585) after we obtained approval from the Ethics Review Committee of the Japan Conference for Clinical Research, a nonprofit organization (approval code: 428, approval date: 10 September 2021). Before the study, its purpose, its procedures and the rights of the participants were fully explained to the participants, and written consent was obtained from all of them. The study was conducted in compliance with the Declaration of Helsinki (Fortaleza, revised in 2013) and the Ethical Guidelines for Life Sciences and Medical Research Involving Human Subjects (Ministry of Education, Culture, Sports, Science and Technology; Ministry of Health, Labor and Welfare; and Ministry of Economy, Trade and Industry Notification No. 1, 2021).