This study is aimed at exploring the effects of glucocorticoids on glucose metabolism in patients with interstitial lung disease. Patients with interstitial lung disease who is on the medication of 15mg prednisolone and 7.5mg prednisolone conduct the continuous glucose monitoring (CGM). The data attained from the CGM are used to define the glycemic characteristics in patients using glucocorticoids and the difference of glucose features due to different doses.