The investigators will perform a randomized, double-blind placebo controlled study to determine if co-administration of the selective 11β-HSD1 inhibitor, AZD4017, limits the adverse effects of short-course exogenous glucocorticoid administration. 32 healthy male volunteers will have detailed metabolic investigations including 2-step hyperinsulinaemic euglycaemic clamps (with stable isotope measurements of lipid and carbohydrate metabolism), as well as assessment of skeletal muscle forearm glucose uptake. All volunteers will then be treated with Prednisolone (20mg daily) and randomized to the co-administration of placebo or AZD4017. After 1 week of therapy, all investigations will be repeated. Our hypothesis is that the adverse metabolic effects of Prednisolone will be reduced by co-administration of AZD4017.