Funding for this research was provided by:
Ministry of Education, Culture, Sports, Science and Technology (MEXT; 15K04106, MEXT; 16H03264)
Research Funding for Longevity Sciences from the National Center for Geriatrics and Gerontology, Japan (29-42, 28-40)
Text and Data Mining valid from 2019-07-05
Received: 12 February 2019
Accepted: 26 June 2019
First Online: 5 July 2019
Ethics approval and consent to participate
: The study protocol was approved by the Committee of Ethics of Human Research of the National Center for Geriatrics and Gerontology. Written informed consent was obtained from all participants. All methods were performed in accordance with relevant guidelines and regulations.
: Not applicable.
: The authors declare that Liang-Kung Chen is a member of the editorial board as Associated Editor of BMC Geriatrics.