Metformin was significantly superior to placebo with regards to decrease in body weight, body mass index, glycated hemoglobin A1c, fasting insulin, and homeostasis model assessment-insulin resistance (P = 0.002–0.01), but not regarding changes in waist circumference, waist-to-hip rate, leptin, fasting glucose, and blood pressure (P = 0.07–0.33). This evidence concerns the gene LEP and Insulin resistance.