The investigators propose to study the effects of Canagliflozin 100 mg vs Sitagliptin 100 mg (both administered once daily for 12 weeks) on parameters of aerobic exercise capacity and ventilator efficiency by CPET after 12 weeks of active treatment. BP, body water content (Bioelectrical Impedance Analysis [BIA]), body composition (Dual-energy X-ray absorptiometry [DEXA]), cardiac function, diet and biomarkers will be also measured. Subjects with evidence of left ventricular hypertrophy will undergo cardiac magnetic resonance (CMR) imaging.