U.S. Department of Health and Human Services

Metformin is Shown to Be Effective in Treating HIV Patients at Risk for Cardiovascular Disease (CVD)

In a recent clinical trial, scientists studying the effects of the drug metformin and lifestyle modification (LSM) on HIV-infected patients with metabolic syndrome found that metformin significantly reduced the progression of coronary artery calcification (CAC), a risk for CVD. 

Lifestyle modification therapy was not as effective in achieving this goal. HIV-infected patients have high rates of metabolic abnormalities, including a large waistline, high levels of circulating triglycerides, low levels of HDL (“good”) cholesterol, high blood pressure, and high fasting glucose. Having three or more of these contributing factors meets the criteria for metabolic syndrome and increases an individual’s risk of developing CVD and type 2 diabetes. 

Because metformin has been shown to significantly reduce CVD events in individuals without HIV, and because LSM is considered important in the treatment of HIV-infected patients with metabolic syndrome, clinical researchers hypothesized that treatment with metformin and/or LSM would be beneficial for HIV-metabolic syndrome patients in reducing CAC and other risk factors for CVD. To test this hypothesis, the researchers conducted a clinical study in which HIV-metabolic syndrome patients were divided into four groups and treated for 1 year with placebo alone, LSM and placebo, metformin alone, or metformin and LSM. Treatment with metformin and/or LSM was assessed by changes in several criteria including CAC, calcified plaque volume, and other measures of subclinical CVD. In addition, changes in several metabolic indices including fasting blood sugar and HDL-cholesterol levels were measured. Metformin was found to significantly reduce progression of CAC and calcified plaque volume in these patients and had a significantly greater effect on CAC progression than treatment with LSM. Also, metformin improved insulin resistance, a measure of prediabetes and type 2 diabetes. Although LSM had a lesser effect than metformin on CAC progression, it had significantly beneficial effects on HDL-cholesterol and cardio-respiratory fitness. 

The results of this clinical study provide clinicians and researchers with valuable information on metformin as an effective treatment for preventing cardiovascular plaque progression in patients with HIV and metabolic syndrome. In addition, the study has shown LSM to be effective in treating some metabolic conditions in these patients. The metformin finding is particularly advantageous because, although additional studies are needed to assess whether metformin can prevent CVD events, metformin is an FDA-approved generic drug that could be used in the treatment of CVD risk factors in HIV-infected patients with metabolic syndrome. 

Fitch K, Abbara S, Lee H, et al. Effects of lifestyle modification and metformin on atherosclerotic indices among HIV-infected patients with the metabolic syndrome. AIDS 26: 587-597, 2012.