MON-LB102 Metformin-Induced Weight Loss in Patients With or Without Type 2 Diabetes/Prediabetes

Background: Metformin is the first-line pharmacologic treatment for type 2 diabetes (T2DM). Its use has been associated with significant weight loss in patients with obesity with or without T2DM. However, it is unknown whether weight loss outcomes differ with metformin monotherapy in patients with excess weight and euglycemia compared to patients with T2DM/prediabetes (PreDM).

Methods: This is a retrospective study of new patients with overweight/obesity seen at an academic weight management center between 4/1/14-4/1/16. Patients who received metformin as a sole pharmacotherapy were identified, and data pertaining to demographics, medications, comorbidities, and weight changes during 1-year follow-up were obtained from their electronic medical records. Mean and categorical weight losses were compared between patients with and without T2DM/PreDM. We also assessed the rate of metformin discontinuation due to side effects, lack of efficacy or other reasons in the entire cohort.

Results:

Of 1056 patients who were prescribed metformin for weight loss over the 2-year study period and had at least 2 office visits, 99 (9.38%) discontinued the medication due to the following reasons: side effects 59 (60%), lack of efficacy 15(15%) or other reasons 25(25%). A total of 254 patients received metformin as a sole pharmacotherapy for weight loss and had 6 and/or 12-month follow-up visits. In this cohort, the mean age was 53 ± 14 years, 66% were women. The mean BMI was 35 ± 7 kg/m². The average percent weight loss at 6 and 12 months were similar in patients with euglycemia compared to patients with T2DM/PreDM (6.12% ± 5.68 vs 6.36% ± 6.52 p=0.73 at 6 months; 7.13% ± 6.42 vs 7.23% ± 7.74 p=0.93 at 12 months). The proportion of patients who experienced ≥5% weight loss was similar in both groups at 6-month (54.04 vs 54.55%, p=0.94) and 12-month follow-up visits (63.95 vs 55.42%, p=0.26). The proportion of patients who experienced ≥10% weight loss was also similar in both groups at 6-month (25.81 vs 27.72%, p=0.81) and 12-month follow-up visits (33.72 vs 30.12%, p=0.62).

Discussion: Among patients with obesity, metformin as a sole pharmacotherapy for weight loss achieved significant and comparable weight reduction in patients with or without T2DM/PreDM. Further studies are needed to evaluate the long-term weight loss in patients with euglycemia.