DPP4 and metabolic syndrome: Subgroup analysis found lower MACCEs risk in the pioglitazone users without insulin therapy (6.44% vs. 10.04% (HR): 0.59, 95% (CI): 0.42–0.82) and lower MACCEs related death (2.76% vs. 3.84% (HR): 0.61, 95% (CI): 0.40–0.95) in the pioglitazone group with dyslipidemia, when comparing with DPP4-inhibitors users.