OBJECTIVES: FDA-approved sodium-glucose co-transporter-2 inhibitors (SGLT2s) were compared to the most-prescribed US dipeptidyl-peptidase-4 (DPP-4) inhibitor, sitagliptin (SITA) to determine whether SGLT2s yielded equal or better hemoglobin A(HbA), body-weight and blood-pressure (BP) outcomes as add-on therapy when MET monotherapy no longer controlled blood glucose. This research is based on a systematic review and meta-analysis of RCTs as add-on therapy to MET through 9/30/2014. METHODS: The Cochrane Register, ClinicalTrials.gov, MEDLINE and manufacturer websites were searched for RCTs of canagliflozin, dapagliflozin, empagliflozin or SITA to extract outcomes. Subjects were T2D patients with baseline HbA>7% and ≤10.5%, age 18-80 years, on stable MET monotherapy ≥1500 mg for ≥8 weeks. Trials tested single-agent add-on therapy, with MET monotherapy control. Trial means and standard deviations were pooled, using random-effects models for two FDA-approved doses (SGLT2s) and the single, 100-mg SITA dose tested.  RESULTS: Nine RCTs (12-26 weeks) met criteria for inclusion (pooled n for SGLT2 vs. SITA = 2370 and 2293, respectively). Control-adjusted effects showed .57%, .68% and .66% reductions in HbA