Effect of Short Course of Glucocorticoid in Patients With Diabetes Mellitus(DM) Type 2

On their scheduled day, participants will be instructed to come to the clinic after an overnight fast of a minimum of 8 hours (subjects can drink water). The participants will be asked to refrain from drinking alcohol for a period of 24 hours before the study days and to not perform strenuous exercise for a period of 48 hours before the study days. The participants will be directed to avoid alcohol and strenuous exercise for the duration of the study. On days 1 and 3 of the study period, participants will be checked into the clinic. A physical examination, including height, weight and waist circumference, and finger-stick glucose will be performed. A 75-g OGTT will be performed with venous samples for measurement of glucose, insulin and C-peptide levels obtained at 0, 30 and 60 minutes starting immediately after the ingestion of the 75 g glucose solution. After samples are collected on day 1, participants will be administered their first dose of steroid, prednisone 40 mg, and be given a packet of two additional doses for the rest of the study period. The investigators may only give 1 additional dose to them and have the participants take the last dose in clinic on day 3 two hours before the OGTT. Subjects will take prednisone 40 mg once daily for three days to be consumed around 8:00am on days 2 and 3. This dose was chosen as a typical high-dose glucocorticoid regimen. On the third day, the participants will again visit the clinic after an overnight fast of a minimum 8 hours and undergo a physical examination and OGTT just as on day 1. Participants will be instructed to check pre-prandial (before breakfast, lunch and dinner), and bed time (around 10:00 pm) blood glucose (BG) levels and to record all values for a total of five days (three days while on prednisone and for two days after the second study visit). A member of the study staff will call each participant daily around 7:00 pm to obtain BG values. Compliance with the study protocol will be assessed at this time as well. Any subject not compliant with study medications will be excluded from the study.