RecruitingPhase 4Drug trialThe Effects of Mirabegron and Tadalafil on Glucose Tolerance in PrediabeticsThe investigator hypothesizes that treatment with the ß3 agonist mirabegron results in improved glucose metabolism, including a reversal of prediabetes in obese, insulin-resistant human research participants, and this is further improved by combination therapy with tadalafil. The investigator will comprehensively analyze glucose homeostasis in prediabetic patients treated for 14 weeks with mirabegron, tadalafil or both drugs as compared to a placebo.