1. Department of Internal Medicine, Shikoku Central Hospital, 2233 Kawanoe-cho, Shikoku-chuo, Ehime 799-0193, Japan
2. Department of Cardiovascular Medicine, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
3. Department of Community Medicine and Human Resource Development, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan