Effect of Acarbose on Glycemic Variability in Patients with Poorly Controlled Type 2 Diabetes Mellitus Receiving Stable Background Therapy: A Placebo-Controlled Trial.
STUDY OBJECTIVE
To evaluate the effect of acarbose on glycemic control and glycemic variability, using a continuous glucose-monitoring system, in patients with type 2 diabetes mellitus who were not well controlled on metformin and vildagliptin therapy.


DESIGN
Multicenter, randomized, double-blind, placebo-controlled study.


SETTING
Clinical research units at three hospitals in Italy.


PATIENTS
Fifty-three patients with type 2 diabetes who were taking stable dosages of metformin 850 mg 3 times/day and vildagliptin 50 mg twice/day for at least 3 months and who were not adequately controlled with these therapies.


INTERVENTION
Patients were randomized to either placebo or acarbose 100 mg 3 times/day to be added to their metformin-vildagliptin regimen.


MEASUREMENTS AND MAIN RESULTS
Glycemic excursions were assessed by using a continuous glucose-monitoring system for 1 week. Glycemic control was estimated as the mean blood glucose (MBG) level, the area under the glucose concentration-time curve for a glucose level above 70 mg/dl (AUC above 70) or 180 mg/dl (AUC above 180), and the percentage of time that the glucose level was above 70 mg/dl (T above 70) or 180 mg/dl (T above 180). Intraday glycemic variability was assessed by the standard deviation of the blood glucose level, the mean amplitude of glycemic excursions (MAGE), the M value, and continuous overlapping net glycemic action. Day-to-day glycemic variability was assessed as the mean of daily difference (MODD). The MBG level was ~20 mg/dl lower in the acarbose group than in the placebo group (p<0.05), particularly during the postprandial period. The AUC above 70 did not significantly differ between the two groups, whereas the AUC above 180 was ~40% lower in the acarbose group than in the placebo group during the daytime (p<0.01). The T above 180 was significantly higher in the placebo group than in the acarbose group (31% vs 8%, p<0.01. Moreover, the standard deviation and MAGE values were significantly lower in the acarbose group. The MODD value was not significantly changed in either group, and no significant differences were recorded between groups. All adverse events were mild in both groups, with only a significantly greater frequency of flatulence noted in the acarbose group (5% with acarbose vs 0.5% with placebo, p<0.05).


CONCLUSION
The addition of acarbose to metformin and vildagliptin background therapy in patients with inadequately controlled type 2 diabetes decreased intraday glycemic variability, especially postprandial variability, but it was not associated with a significant change in interday glycemic variability.