Sitagliptin Prophylaxis for Glucocorticoid-Induced Impairment of Glucose Metabolism in Males With the Metabolic Syndrome

Inclusion Criteria: * Caucasian males * Modified from IDF criteria for the metabolic syndrome: * Waist circumference ≥ 94 cm * And at least 2 or more of the following criteria: * TG ≥ 1.7 mmol/L * HDL cholesterol \< 1.03 mmol/L * Blood pressure \>130/85 mmHg (average of three measurements) or treatment of previously diagnosed hypertension * Fasting plasma glucose level (FPG) ≥ 5.6 mmol/L (but no diabetes) Exclusion Criteria: * An allergic or anaphylactic reaction to prednisolone treatment in the past * Clinically relevant history or presence of any medical disorder, which are mentioned in the Summary of Product Characteristics (SPC) as contraindication for the use of prednisolone * Glucocorticosteroid use during the last three months prior to the first dose * Participation in an investigational drug trial within 90 days prior to the first dose * Donation of blood ( \> 100 mL) within 90 days prior to the first dose * History of or current abuse of drugs or alcohol (\>14 U/week) * Use of grapefruit products during the study period * Recent changes in weight and/or physical activity * Serious mental impairment or language problems i.e. preventing to understand the study protocol/aim * Diabetes mellitus (defined as FPG ≥ 7.0 mmol/l and/or 2hPG ≥ 11.1 mmol/l) * Serious pulmonary, cardiovascular, hepatic (ALT, AST more than 3x ULN) or renal disease (serum creatinine \> 135 micromol/L) * History of cardiovascular disease, such as myocardial infarction, cerebrovascular…