Newer diabetes medications may have additional cardiovascular benefits

Researchers found that the use of glucagon-like peptide-1 agonists, known as GLP-1 mimetics, resulted in a systolic blood pressure (SBP) reduction of -2.22 mmHg, a loss of almost six pounds, and a decrease of HbA1c -- an indicator of blood sugar levels -- of 0.41 percent.

"While our findings must be viewed as preliminary it does provide compelling evidence of potential long-term cardiovascular advantages of GLP-1 analogs," said lead investigator Sanjay Rajagopalan, MD, John W. Wolfe Professor of Cardiovascular Medicine and director for vascular research at Ohio State's Wexner Medical Center. "Stroke and heart disease are the leading causes of death in people with diabetes, so this is an area that deserves additional study."

For the meta-analysis, the researchers analyzed 33 randomized studies involving 12,469 patients with type 2 diabetes assessing the glycemic control efficacy of both short acting and long acting GLP-1 mimetics. They specifically looked at GLP-1 impact on sitting systolic blood pressure, diastolic blood pressure, weight, HbA1c and heart rate after 12-56 weeks of treatment. All studies included a comparator group that used other anti-glycemic medications or placebo.

"The significance of our meta-analysis is that it uses direct evidence from both published and unpublished trials that include blood pressure data and glycemic efficacy of GLP-1 agonists with a non-incretin control group including placebo," noted Rajagopalan. "The results were maintained when the placebo controlled trials alone were examined."

The research team also found that the baseline body weight, HbA1c, SBP, study duration, weight loss, HbA1c reduction or heart rate change did not predict the size of the estimated treatment effect or explain heterogeneity between studies.

GLP-1 is a peptide hormone that stimulates insulin and inhibits glucagon secretion in a glucose-dependent manner. Recent studies suggest that the GLP-1 receptor is widely expressed in the cardiovascular system with a variety of effects including improvements in endothelial function that may lead to lowering of blood pressure. GLP-1 mimetics are available globally for the treatment of type 2 diabetes.

Type 2 diabetes is a common form of diabetes mellitus that develops especially in adults and most often in obese individuals. It is characterized by hyperglycemia resulting from impaired insulin utilization coupled with the body's inability to compensate with increased insulin production. Diabetes affects an estimated 23.6 million people in the US (90 percent to 95 percent have type 2 diabetes) -- 17.9 million have been diagnosed, but 5.7 million are unaware they have the disease. According to the most recent statistics, diabetes was the sixth leading cause of death, and the fifth leading cause of death from disease in 2007. Diabetes costs $116 billion annually in direct medical costs and $58 billion annually in indirect costs (loss of work, disability, loss of life).