1. Department of Cardiovascular, Renal and Metabolic Medicine (M.F., A.S., M.T., Y.H., K.M., M.K., H.O., S.S.), Sapporo Medical University School of Medicine, Japan.
2. Department of Public Health (M.K., H.O.), Sapporo Medical University School of Medicine, Japan.
3. Division of Medical and Behavioral Subjects, Department of Nursing, Sapporo Medical University School of Health Sciences, Japan (S.S.).
4. Japan Health Care College, Sapporo (K.S.).