[1] Fukuoka Univ, Sch Med, Dept Internal Med, Jonan Ku, Fukuoka 81401, Japan
[2] Fukuoka Univ, Sch Med, Dept Biochem, Jonan Ku, Fukuoka 81401, Japan
[3] Miyazaki Prefectural Nichinan Hosp, Dept Internal Med, Miyazaki, Japan
[4] Amami Cent Hosp, Kagoshima, Japan
[5] Kagoshima Seikyo Hosp, Dept Internal Med, Kagoshima, Japan
[6] Miyazaki Med Coll, Dept Internal Med, Miyazaki 88916, Japan
[7] Tokyo Teichin Hosp, Dept Endocrinol & Metab, Tokyo, Japan
[8] Teikyo Univ, Sch Med, Dept Internal Med, Tokyo 173, Japan