Funding for this research was provided by:
Grants-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan (Nos. 14570355, 18590572, 23500859, and 26350908)
Received: 21 May 2019
Accepted: 27 August 2019
First Online: 5 September 2019
Ethics approval and consent to participate
: All participants gave written informed consent before participating in this study. This study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of Kyorin University School of Medicine.
: Not applicable.
: The authors declare that they have no competing interests.