Abstract
We compared the glycemic efficacy of treatment intensification between quadruple oral antidiabetic drug therapy and once-weekly glucagon-like peptide-1 receptor agonist (GLP-1RA)-based triple therapy in patients with poorly controlled type 2 diabetes mellitus refractory to triple oral therapy. For 24 weeks, changes in glycosylated hemoglobin (HbA1c) from baseline were compared between the two treatment groups. Of all 96 patients, 50 patients were treated with quadruple therapy, and 46 were treated with GLP-1RA therapy. Reductions in HbA1c for 24 weeks were comparable (in both, 1.1% reduction from baseline; P=0.59). Meanwhile, lower C-peptide level was associated with a lower glucose-lowering response of GLP-1RA therapy (R=0.3, P=0.04) but not with quadruple therapy (R=-0.13, P=0.40). HbA1c reduction by GLP-1RA therapy was inferior to that by quadruple therapy in the low C-peptide subgroup (mean, -0.1% vs. -1.3%; P=0.04). Treatment intensification by switching to quadruple oral therapy showed similar glucose-lowering efficacy to weekly GLP-1RA-based triple therapy. Meanwhile, the therapeutic response was affected by C-peptide levels in the GLP-1RA therapy group but not in the quadruple therapy group.