Canaglifozin and sitagliptin are both anti-diabetic medications with different mechanisms of action. Canaglifozin is an SGLT2 inhibitor, which works by lowering glucose levels by increasing glucose secretion in the urine. Sitagliptin is a DPP4-inhibitor, which increases the hormone levels of GLP-1 and GIP.
In a clinical phase 3 trial led by Schernthaneret al, a comparison is made between the effects of canagliflozin and sitagliptin add-on therapy among type 2 diabetic patients who were experiencing inadequate control of their glucose while on metformin and a sulfonylurea. Subjects in the study either received canagliflozin 300 mg or sitagliptin 100 mg in addition to their metformin +sulfonylurea and data was collected for a 52-week period. A portion of the subjects in the study took a 3-hr frequently sampled mixed-meal tolerance test at baseline and at week 52. During this test, several labs were measured at different times, the labs included: plasma glucose levels, insulin, and c-peptide.
Results indicated that both canagliflozin and sitagliptin decreased fasting blood glucose and post-prandial glucose levels when compared to baseline. However, patients on canagliflozin add-on therapy exhibited a significantly lower fasting plasma glucose reading than those on sitagliptin therapy. Furthermore, both add on therapies produced similar increases in insulin secretion rate (~9 mM) and in mean B-cell glucose sensitivity.
In conclusion, researchers concluded that after one year of treatment with canagliflozin or sitagliptin in diabetic patients with insufficient response from metformin and sulfonylurea, both medications displayed improvements in beta-cell functioning, but canagliflozin was better at lowering fasting blood glucose.
Presented at EASD Barcelona, September 2013. Schernthaner G, et al. Effects of one-year treatment with canagliflozin or sitagliptin on glycaemic control and beta cell function measures in subjects with type 2 diabetes on metformin + sulfonylurea.