Received: 28 December 2020
Accepted: 28 May 2021
First Online: 21 June 2021
: This study was approved by the Institutional Review Board of the University of Tokyo (2018030NI). As the data we obtained were anonymised, no consent was required.
: Not applicable.
: This study was conducted at the Department of Prevention of Diabetes and Lifestyle-Related Diseases, which is engaged in a cooperative program between the University of Tokyo and Asahi Mutual Life Insurance Company, which is the funding organisation for the present study. AM, SY, AO, KIK, DN, HK and TK were members of the department when the study was conducted. AM, KIK and DN are employees of Asahi Mutual Life Insurance Company.