[1] Hokkaido Univ, Fac Med, Dept Cardiovasc Med, Kita Ku, Kita 15 Nishi 7, Sapporo, Hokkaido 0608638, Japan
[2] Hokkaido Univ, Grad Sch Med, Kita Ku, Kita 15 Nishi 7, Sapporo, Hokkaido 0608638, Japan
[3] Hokkaido Univ, Fac Med, Dept Biostat, Sapporo, Hokkaido, Japan
[4] Hokkaido Univ, Grad Sch Med, Sapporo, Hokkaido, Japan
[5] Hokusho Univ, Grad Sch Lifelong Sport, Ebetsu, Hokkaido, Japan