Changes in antihyperglycemic therapy with insulin initiation for type 2 diabetes.
Dotimas, James   (Johns Hopkins University)
Mentor: Clark, Jeanne (Johns Hopkins University School of Medicine)
Due the natural history of type 2 diabetes, many patients will often require insulin; however, the American Diabetes Association has few clear recommendations for adjusting a patient’s noninsulin antihyperglycemic medications during insulin initiation other than to continue metformin use. Several meta-analyses suggest metformin continuation in patients starting insulin has many proven benefits, including improved glycemic control, reduced insulin requirement, and less weight gain. In order to determine the rate of continuation of metformin and clinical factors affecting the decision to continue metformin when starting insulin, we examined medication data and participant characteristics from the Action for Health in Diabetes (Look AHEAD) trial. The Look AHEAD trial compared the effects of an Intensive Lifestyle Intervention aimed at =7% weight loss versus Diabetes Support and Education in overweight and obese individuals. In participants starting insulin during the trial period and has complete, reviewed medication lists (N = 931), we calculated the proportions of patients continuing metformin and determined clinical factors relevant to metformin continuation using a logistic regression model. Most patients (747/931; 80.2%) were using metformin prior to insulin initiation, and of these patients, many of them continued metformin use after starting insulin (600/747; 80.3%). Our logistic regression model using only those participants that indicated usage of metformin prior to insulin initiation (n = 747) found that metformin continuation is less likely with older age, lower income, higher serum creatinine (sCr), and polypharmacy. These data comply with FDA labeling prior to 2016 for metformin and sCr, which was relevant to the study period. The association of socioeconomic status with metformin continuation requires further exploration, while the effect of polypharmacy confirms the complexity of managing type 2 diabetes.