1. Department of Internal Medicine (K.M.K., S.H.C., S.L., J.H.M., H.C.J.), Seoul National University Bundang Hospital and Seoul National University College of Medicine, Seongnam 137-761, Korea
2. Department of Internal Medicine (J.H.K., C.S.S.), Seoul National University Hospital and Seoul National University College of Medicine, Seoul 110-744, Korea
3. Department of Internal Medicine (S.W.K.), Borame Hospital and Seoul National University College of Medicine, Seoul 156-707, Korea