Fibrate Plus Glitazone May Lower Serum HDL Cholesterol

By Karla Gale

Combination treatment with fenofibrate and a thiazolidinedione occasionally leads to decreases in serum HDL cholesterol levels, 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," senior author Dr. Greg Bondy, a physician at St. Paul's Hospital in Vancouver, British Columbia, said in an interview with Reuters Health.

After he and colleagues discovered this unusual effect, they conducted a chart review to identify patients on combination therapy.

According to the report in the September issue of Diabetes Care, they identified nine HIV-positive patients taking fenofibrate and rosiglitazone whose serum HDL cholesterol concentrations had fallen an average of 33%. They also encountered 12 HIV-negative patients with diabetes mellitus whose HDL cholesterol fell by 20%. However, 12 HIV-positive patients on fenofibrate alone exhibited a mean increase of 19%.

On cessation of one of the two drugs, HDL cholesterol levels returned to normal, the authors report.

So far, the team has not identified any factor that is common to patients who share this characteristic. Dr. Bondy noted that he has observed this phenomenon with both rosiglitazone and pioglitazone.

"Only a small percentage people develop this problem," Dr. 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 advises clinicians to check patients' lipid levels after they are put on combination therapy. If HDL levels fall, then one of the two drugs should be discontinued.

09/15/04

Diabetes Care 2004;27: 2241-2242.