According to a new study, the Type 2 diabetes drug pioglitazone (brand name Actos) appears to slow the progression of coronary atherosclerosis, or narrowing of the heart’s arteries due to plaque buildup, better than an older diabetes drug, glimepiride (Amaryl, also available generically). People who have diabetes are at increased risk of developing heart disease, and coronary atherosclerosis can lead to angina or heart attack.
Results of the study, which is called the Pioglitazone Effect on Regression of Intravascular Sonographic Coronary Obstruction Prospective Evaluation (PERISCOPE) trial, were published on the Web site of The Journal of the American Medical Association on March 31. In the trial, more than 300 people who had both Type 2 diabetes and heart disease were randomly assigned to take pioglitazone (a thiazolidinedione drug, which makes the body more sensitive to insulin) or glimepiride (a sulfonylurea drug, which increases the body’s secretion of insulin) for 18 months. The study was double-blind, meaning that neither the participants nor the researchers knew which drug the participants had received. The amount of plaque buildup in the heart’s arteries was measured at the beginning and end of the study with a special imaging technique.
The researchers found that the people who took pioglitazone had a 0.16% decrease in plaque, while those who took glimepiride had a 0.73% increase—a significant difference. This finding led the researchers to conclude that “treatment with pioglitazone resulted in a significantly lower rate of progression of coronary atherosclerosis compared with glimepiride.”
The pioglitazone users fared better than the glimepiride users in some other, secondary measures too: They had larger drops in HbA1c levels (0.55% vs. 0.36%), greater increases in HDL (”good”) cholesterol levels (5.7 mg/dl vs. 0.9 mg/dl), and a decrease in triglyceride levels of 16.3 mg/dl compared to an increase of 3.3 mg/dl in the glimepiride group. Hypoglycemia (low blood glucose) was more common in the glimepiride group.
However, the pioglitazone group also experienced some adverse side effects. While both study groups gained some weight, members of the pioglitazone group gained about 4.4 pounds more than the glimepiride group. Also, edema (swelling due to fluid retention) and bone fractures occurred more frequently in the pioglitazone group. Thiazolidinedione drugs have been linked to increases in risk of both congestive heart failure and bone fractures in the past (see “New Data on Avandia; New Warnings for TZD Drugs,” “Diabetes Drug Linked to Fracture Risk,” and “Second Diabetes Drug Linked to Increased Fractures”).
The study was designed by researchers at The Cleveland Clinic, including Steven Nissen, M.D., who carried out the much-publicized meta-analysis linking rosiglitazone (another drug in the thiazolidinedione class) to increased risk of heart attack last year (see “Type 2 Drug Avandia Linked to Increased Risk of Heart Attacks”). The PERISCOPE study was funded by Takeda Pharmaceuticals, which manufactures pioglitazone. Another analysis funded by Takeda that was published last year also seemed to show that pioglitazone may have a protective effect on the heart (see “Actos Tops Avandia in Heart Safety Studies”).
Takeda also manufactures two combination diabetes drugs, one of which, Duetact, combines the two drugs studied in the PERISCOPE trial, pioglitazone and glimepiride. The other, ACTOplus met, combines pioglitazone and metformin.