A 43-year-old man with a strong family history of diabetes mellitus presented to his primary care physician requesting interventions to decrease his cardiovascular risk. He was actively working on intensive lifestyle modifications, such as diet and exercise, with minimal success. The patient was overweight, with a body mass index (BMI) of 29 kg/m² and a waist circumference of 108 cm. His blood pressure was mildly elevated, at 140/86 mm Hg. His lipid values were as follows: total cholesterol, 175 mg/dL; triglycerides, 281 mg/dL; high-density lipoprotein (HDL) cholesterol, 35 mg/dL; and calculated low-density lipoprotein (LDL) cholesterol, 135 mg/dL. His fasting plasma glucose level on 2 occasions was 101 mg/dL and 109 mg/dL.

The physician explained to the patient that he met the criteria for metabolic syndrome and was at significant risk for developing type 2 diabetes. Treatment with 850 mg of metformin (Fortamet, Glucophage, Riomet) twice daily was recommended, in addition to continuing intensive lifestyle interventions. After 6 months of treatment, the patient had lost weight, reduced his BMI to 26 kg/m², and decreased his waist circumference to 99 cm. Laboratory evaluation showed an HDL cholesterol level of 37 mg/dL, a calculated LDL cholesterol level of 128 mg/dL, and a fasting glucose level of 95 mg/dL. The patient chose to continue with this treatment plan, demonstrating similar weight and laboratory values 1 year later.