1. School of Medicine, Department of Internal Medicine I, Oita Medical University, Hasama, Oita, 879-5593
2. Department of Physiology, School of Medicine, Niigata University, Niigata, 951-8151, Japan
3. School of Nursing, Community Health and Gerontological Nursing, Oita Medical University, Hasama, Oita, 879-5593