Mariko Tsuchiya, Ryoichi Misaka, Institute of Geriatrics, Tokyo Women’s Medical University, Tokyo 150-0002, Japan
Kosaku Nitta, Ken Tsuchiya, Department of Medicine IV, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
Author contributions: Tsuchiya M was the principle investigator; Misaka R and Nitta K revised the article; Tsuchiya K was organizing the maf relating project, analyzing data and drafting the article.
Supported by A Grant-in-Aid for Scientific Research of Japan (C; 17591443: Tsuchiya M, C; 26461243: Tsuchiya K).
Conflict-of-interest: The authors have no conflict of interest directly relevant to the content of this article.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Ken Tsuchiya, MD, PhD, Clinical Professor, Department of Medicine IV, Tokyo Women’s Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan. email@example.com
Telephone: +81-3-33538111 Fax: +81-3-33560293
Received: July 18, 2014
Peer-review started: July 19, 2014
First decision: September 4, 2014
Revised: November 17, 2014
Accepted: December 3, 2014
Article in press: December 10, 2014
Published online: February 15, 2015