1. Tenyokai Chuo Hospital, 6-7 Izumi-cho, Kagoshima 892-0822, Japan
2. Tanegashima Medical Center, 7463 Nishinoomote, Kagoshima 891-3198, Japan
3. Department of Cardiovascular Medicine and Hypertension, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-0075, Japan