Some people with diabetes have an unexpected decrease in HDL (“good”) cholesterol when they take fenofibrate to reduce triglyceride levels, along with an insulin sensitizer such as Avandia, according to a report from Canadian investigators.

“Normally HDL cholesterol goes up with these drugs, but in some selected individuals we had this paradoxical fall,” Dr. Greg Bondy, a physician at St. Paul’s Hospital in Vancouver, British Columbia, said in an interview with Reuters Health.

According to the team’s report in the issue of Diabetes Care, they first identified nine HIV-positive patients taking Avandia and fenofibrate (Tricor, Lipidil and Lofibra are brand names of the drug) whose HDL cholesterol levels had fallen an average of 33 percent.

The investigators also uncovered 12 patients with diabetes, none of whom had HIV, whose HDL cholesterol fell by 20 percent while on the combination therapy.

When one or other of the two drugs was stopped, HDL cholesterol levels returned to normal, Bondy and colleagues report.

So far, they have not identified any factor that is common to patients who experience the paradoxical drop in HDL. Bondy noted that he has observed this phenomenon with both Avandia and a similar drug, Actos.

“Only a small percentage people develop this problem,” Bondy emphasized. “And we don’t know the consequences of having a lowered HDL; it may not necessarily be a bad thing.”

But until this issue is better understood, he recommends checking patients’ lipid levels after they start on combination therapy. If HDL levels fall, then one of the two drugs should be discontinued.

SOURCE: Diabetes Care, September 2004.