The primary purpose of this study is to evaluate the efficacy, durability, and mechanism of HbA1c reduction produced by the combination of pioglitazone plus tirzepatide compared to metformin plus sitagliptin in patients with recently diagnosed type 2 diabetes mellitus.

This is a randomized open label controlled 2 arm study (with one of the arms containing 3 sub-groups) which aims to examine the effectiveness and long term effects on HbA1c reduction produced by the combination of pioglitazone plus tirzepatide versus metformin plus sitagliptin in recently diagnosed type 2 diabetes mellitus (T2DM) patients. A subgroup of patients from group 1 will be invited to participate in a sub-study which lasts for 6 months and aims at exploring the metabolic/molecular mechanisms responsible for the study results. The selection of subjects to each subgroup will be done randomly and the end of sub-study, subjects will continue therapy and follow-up from month 6 on in the main study.