1. Department of Cardiology, The Heart Institute of Japan, Tokyo Women’s Medical University, 8-1, Kawada-cho, Shinjyuku, Tokyo 162-8666, Japan
2. Division of Comprehensive Sleep Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
3. Institute of General Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
4. National Hospital Organization Yokohama Medical Center, Kanagawa 245-8575, Japan
5. National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan