[1] Univ Ulsan, Dept Family Med, Asan Med Ctr, Coll Med, Seoul 138736, South Korea
[2] Korea Univ, Guro Hosp, Coll Med, Dept Family Med, Seoul 152050, South Korea
[3] Korea Univ, Guro Hosp, Coll Med, Div Endocrinol & Metab,Dept Internal Med, Seoul 152050, South Korea