Continuous glucose profiles with vildagliptin versus sitagliptin in add-on to metformin: Results from the randomized Optima study

Aim. - To compare continuous glucose monitoring (CGM) profiles on vildagliptin versus sitagliptin in addition to metformin, in patients with inadequately controlled type 2 diabetes mellitus (HbA(1c) 6.5-8.0%). Methods. - A multicenter, prospective, randomised, open-label study with blinded endpoint analysis. CGM data acquired over three days - firstly on metformin alone and then 8 weeks after the addition of either vildagliptin (n=14) or sitagliptin (n=16) -were blinded and analyzed centrally. Results. - Incomparable populations with a mean baseline HbA(1c) of 7.1%, 24-hour glucose variability - measured by mean amplitude of glucose excursions and standard deviation of mean glucose concentration - showed similar improvement on both drugs versus metformin alone. In contrast, a series of predefined parameters reflecting daily glycaemic control - mean 24-hour blood glucose concentration, and the times spent in the optimal glycaemic range (70-140 mg/dL) and above the hyperglycaemic thresholds of 140 and 180 mg/dL together with the corresponding AUC values - were significantly improved from baseline only in the vildagliptin arm. In addition, overall hyperglycaemia (AUC[24 h] >100 mg/dL) significantly dropped from baseline on vildagliptin [-37%] but not on sitagliptin [-9%], while postprandial hyperglycaemia (AUC[0-4 h] x 3) was significantly reduced on both, and basal hyperglycaemia (overall - postprandial hyperglycaemia was reduced only on vildagliptin [-41%; P=0.04]). Conclusions. - The addition of a DPP-4 inhibitor significantly reduced glycaemic variability with no difference between the two drugs. However, vildagliptin induced better circadian glycaemic control than sitagliptin with a significant decrease on overall hyperglycemia, mainly driven by reduction on basal hyperglycaemia. (C) 2012 Elsevier Masson SAS. All rights reserved.