Text and Data Mining valid from 2018-03-16
Received: 22 December 2017
Accepted: 9 March 2018
First Online: 16 March 2018
Compliance with ethical standards
: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
: The Korea National Health and Nutrition Examination Survey was approved by the Institutional Review Board of the Korea Centers for Disease Control and Prevention (approval numbers: 2007-02CON-04-P, 2008-04EXP-01-C, 2009-01CON-03-2C, and 2010-02CON-21-C). In addition, this study was performed in accordance with the ethical principles of the Declaration of Helsinki.
: Written informed consent was obtained from all participants.