Effects of the addition of acarbose to insulin and non-insulin regimens in veterans with type 2 diabetes mellitus

OBJECTIVES The primary objective of the study was to assess the mean change in hemoglobin A1c (HbA1c) when acarbose was added to insulin and non-insulin regimens in patients with type 2 diabetes mellitus (T2DM). Secondary objectives were to evaluate the discontinuation rate of acarbose, and to assess the number of patients who were placed on insulin despite the addition of acarbose. METHODS A retrospective chart review was conducted on veterans with T2DM initiated on acarbose between October 1, 2013 and December 31, 2013. To be included, patients must have had a refill history indicating at least 3 months of acarbose use and HbA1c readings within 6 months prior to initiation and after at least 3 months of use. Excluded patients were those with type 1 diabetes mellitus, serum creatinine ≥2 mg/dL at acarbose initiation, or a diagnosis based on ICD-9 codes for an existing gastrointestinal condition or liver cirrhosis. The two-tailed, paired t-test was used for analysis of the primary objective and descriptive statistics were used for all other outcomes. RESULTS Of the 146 patients screened, 102 patients were included in the study. Exclusions were primarily due to patients not being on acarbose for at least 3 months (n=43). The average HbA1c before and after acarbose initiation was 9.08% (SD=1.74) and 8.43% (SD=1.74) respectively, with an average HbA1c reduction of 0.65% (n=102, p=0.0005). Forty patients (39.2%) discontinued acarbose after at least 3 months of use. Of the 73 patients not on insulin at the time of acarbose initiation, 19 (26%) were started on insulin therapy despite addition of acarbose. CONCLUSION Acarbose can be considered in patients who may reach their HbA1c goal with minimal HbA1c reduction. However, adverse effects are a limitation to use. Potential risks and benefits should be assessed and discussed with the patient prior to prescribing acarbose.