Iwasaki, Masanori
Motokawa, K.
Watanabe, Y.
Shirobe, M.
Inagaki, H.
Edahiro, A.
Ohara, Y.
Hirano, H.
Shinkai, S.
Awata, S.
Article History
Received: 6 May 2020
Accepted: 28 May 2020
First Online: 3 July 2020
Ethical standards
: The current study was conducted in accordance with the ethical principles of the Declaration of Helsinki and was approved by the ethics committee of the Tokyo Metropolitan Institute of Gerontology (approval number 9 and 31 in 2016). All participants provided a written informed consent prior to participating in the current study.