Deadly Drug Helps Control Diabetes

Type 2 diabetes patients may control blood sugar with torcetrapib

(RxWiki News) Drugs do not always work like they are supposed to. In some cases - such as that of the cholesterol drug torcetrapib - they may help fight a disease different than the one they were made to treat.

Torcetrapib may help people with type 2 diabetes control their disease. The drug seems to lower blood sugar levels and reduce patients' resistance to insulin, a hormone that manages blood sugar.

"Take a certain type of cholesterol drug to keep your diabetes under control."

Philip J. Barter, M.B.B.S., Ph.D., from the University of Sydney, and colleagues looked at data from a clinical trial that was stopped when researchers saw that torcetrapib may raise the risk of heart problems and death.

Dr. Barter and his fellow researchers found that type 2 diabetes patients who took torcetrapib along with Lipitor (atorvastatin) had lower levels of blood sugar and insulin, compared to patients who took only Lipitor. The patients who took torcetrapib also became less resistant to insulin, which means that the body allowed insulin to do its job of removing excess sugar from the blood.

Torcetrapib is part of a class of cholesterol drugs known as cholesteryl ester transfer protein (CEPT) inhibitors. In other words, they are drugs that suppress the cholesteryl ester transfer protein, which increases levels of "good" cholesterol (HDL cholesterol) while lowering levels of "bad" cholesterol (LDL cholesterol).

"We found that torcetrapib also improved diabetes control," said Dr. Barter. "Unfortunately, however, torcetrapib had serious adverse side effects that were unrelated to inhibition of CEPT and will never be used again in humans."

If it were not for the higher death risk associated with torcetrapib, this would have been good news for diabetes patients trying to get their blood sugar under control. However, other drugs similar to torcetrapib may do the same job without the possibility of harming patients.

"The good news is that there are other CEPT inhibitor drugs in development (dalcetrapib and anacetrapib) that increase the level of protective HDL cholesterol without having the adverse side effects found with torcetrapib," said Dr. Barter. 

The study's authors write that torcetrapib may help with blood sugar control because it increases HDL levels, but more research needs to be done to see if this is the case.

Even though torcetrapib will never be offered to patients, it may be possible that other CEPT inhibitors will help people with type 2 diabetes take control of their disease.

"The real place of these drugs in clinical practice will depend on the results of the ongoing clinical trials with dalcetrapib and anacetrapib," Dr. Barter concludes.

For their study, Dr. Barter and colleagues analyzed data from the ILLUMINATE trial in order to look at the effects of torcetrapib on blood sugar control. The trial involved 6,661 participants. The participants were split into two groups: one treated with torcetrapib and Lipitor while the other group received Lipitor alone.

At the beginning of the study, both groups had the same levels of blood sugar, insulin, hemoglobin A1c (a test that measures blood sugar control), and insulin resistance. After three months, the diabetes patients taking torcetrapib and Lipitor had blood sugar levels that were 0.34 mmol/L lower than those who took only Lipitor. These patients also had insulin levels that were 11.7 μ U/mL lower than those who took Lipitor alone.

Insulin resistance values dropped from 49.1 to 47.3 for the patients who took torcetrapib and Lipitor.

The rest of the findings by Dr. Barter and colleagues are published in Circulation: Journal of the American Heart Association.

Review Date: 
July 20, 2011