[1] Dong A Univ, Coll Med, Dept Prevent Med, Seo Gu, Pusan 602714, South Korea
[2] Nagoya City Univ, Sch Med, Dept Internal Med 2, Nagoya, Aichi 467, Japan
[3] Yale Univ, Sch Med, Dept Epidemiol & Publ Hlth, New Haven, CT 06510 USA
[4] Kobe Asahi Hosp, Kobe, Hyogo, Japan