1. The Division of Nephrology, Faculty of Medicine, Department of Internal Medicine, Saga University, Nabeshima 5-1-1, Saga-city, Saga 849-8501, Japan
2. The Division of Nephrology, Department of Internal Medicine, Fukumitsu Hospital, Kashiihama 4-10-1, Higashi-ku, Fukuoka-city, Fukuoka 813-0016, Japan
3. The Department of Nephrology, Abe Clinic, Taharashinmachi 2-3-8, Kokuraminani-ku, Kitakyushu-city, Fukuoka 800-0226, Japan
4. The Department of Medicine and Clinical Science (Second Department of Internal Medicine), Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka-city, Fukuoka 812-8582, Japan