A 58-year-old man is newly diagnosed with type 2 diabetes mellitus after a fasting plasma glucose of 8.0 mmol/L and HbA1c of 7.8%. He has no established cardiovascular disease, eGFR is 70 mL/min/1.73 m², and BMI is 31 kg/m². According to Diabetes Canada pharmacologic guidelines, what is the most appropriate initial pharmacologic management?