CV Risk Lower with Metformin

SAN DIEGO—Older patients with type 2 diabetes have a significantly higher likelihood of experiencing a cardiovascular (CV) event within two years if they start treatment with a sulfonylurea drug than with metformin, researchers reported at the 71st Scientific Sessions of the American Diabetes Association.

“The results are important because elderly patients with diabetes are at particular risk for cardiovascular disease, and sulfonylureas continue to remain a commonly used medication in this population,”said Alex Z. Fu, PhD, an associate faculty member in the Department of Quantitative Health Sciences at Cleveland Clinic in Ohio, told Renal & Urology News.

For their study, the investigators examined the potential association between initial monotherapy with sulfonylurea or metformin and subsequent CV events in older type 2 patients using data from an electronic medical record database.

The analysis included 8,656 patients with type 2 diabetes aged 65 years and older. The patients had been prescribed antihyperglycemic therapy between 2003 and 2008 and had remained on their prescribed therapy for at least 90 days. 

Patients who had a CV event (ischemic heart disease, myocardial infarction, stroke, transient ischemic attack, and peripheral arterial disease) within the prior year were ineligible. 

The incidence of CV events was 14.8% among patients who started therapy with a sulfonylurea compared with 11.6% among those who started on metformin within two years of follow-up.

The difference between the two groups was largely due to an increased incidence of ischemic heart disease with a sulfonylurea (7.1%) compared with metformin (1.9%).

Additionally, sulfonylurea therapy was associated with a shorter time to a first CV event compared with metformin.

Dr. Fu cautioned that the study was a retrospective analysis and patients were not randomized to treatments. Also, the analysis did not control for treatment discontinuations or subsequent prescriptions for other antihypertensive agents.  Unmeasured variables such as on-treatment changes in clinical and laboratory measures may also have contributed to the findings, he said.

Loading links....