[1] Tohoku Univ, Coll Med Sci, Dept Nursing, Aoba Ku, Sendai, Miyagi 9807585, Japan
[2] Tohoku Univ, Grad Sch Med, Dept Med & Sci Sports & Exercise, Sendai, Miyagi 980, Japan
[3] Tohoku Univ, Sch Med, Dept Internal Med, Div Gastroenterol, Sendai, Miyagi 980, Japan
[4] Mizusawa Gen Hosp, Dept Med, Mizusawa, Japan