[1] Catholic Univ Korea, Seoul St Marys Hosp, Dept Internal Med, Coll Med,Div Endocrinol & Metab, Seoul, South Korea
[2] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Internal Med, Seoul, South Korea
[3] Korea Univ, Coll Med, Dept Internal Med, Div Endocrinol & Metab, Seoul, South Korea
[4] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Div Endocrinol & Metab,Dept Med, Seoul, South Korea
[5] Yonsei Univ, Coll Med, Dept Internal Med, Div Endocrinol & Metab, Seoul, South Korea
[6] Yonsei Univ, Coll Med, Dept Internal Med, Div Endocrinol & Metab, 50-1 Yonsei Ro, Seoul 03722, South Korea