(Ivanhoe Newswire) -- A new group of studies adds to the growing body of medical literature about the cardiovascular risks that may be associated with certain pain relievers.

A trial including 65 centers in seven countries evaluated the effects of COX-2 inhibitors and naproxen on 24-hour blood pressure readings in patients with type 2 diabetes, hypertension and osteoarthritis. Patients received celecoxib (Celebrex), rofecoxib (Vioxx), or naproxen (Aleve).

Researchers found, "Reductions in osteoarthritis symptoms, including pain, mobility and stiffness, were similar in all treatment groups." Also, the average top number in blood pressure readings increased significantly in patients taking rofecoxib but not from taking celecoxib or naproxen.

Researchers conclude, "These results suggest the need for careful monitoring and control of blood pressure when NSAIDs or COX-2 inhibitors are chosen for osteoarthtitis management for patients with hypertension and type 2 diabetes and further suggest need for careful evaluation of currently available as well as future COX-2 inhibitors and nonspecific NSAIDs in this population."

In a separate study, researchers from the University of Maryland, Baltimore, observed more than 6,000 patients and found COX-2 inhibitors did not increase the risk for cardiovascular events over non-naproxen NSAIDs.

They conclude, "The widespread use of COX-2 inhibitors will not be associated with an increase in thrombotic or coronary artery events. This is particularly important because NSAIDs are often used in older, higher-risk patients."