High-dose statins raise risk of diabetes

Taking a high-dose statin to lower cholesterol may increase risk of developing diabetes by as much as 12%, but the heart benefits of statins still outweigh the risks, investigators say.

Doctors say the new research made public should not prompt anyone to stop taking statins, but patients on high doses should be screened regularly for diabetes.

The findings on two of the biggest-selling statins may lead doctors to choose Lipitor (atorvastatin) when high doses are needed versus the less expensive, generic version of Merck & Co's Zocor (simvastatin).

While both drugs raise the risk of diabetes, high-dose Lipitor worked far better than generic Zocor at cutting heart risks, the team reported in the Journal of the American Medical Association.

Study after study has shown that taking statins can lower the risk of heart attacks and strokes, but some findings have suggested that the drugs may raise the risk of diabetes.

The study

To see if dose is a factor, researchers from St George's, University of London and the University of Glasgow analyzed data from five different studies involving 32,752 patients who were treated with high and moderate doses of statins.

Over a five-year period, 2,749 participants, or 8.4%, developed diabetes, and 6,684 participants, or 20%, had a major heart problem.

"Overall, we found that high doses were associated with a 12% increased risk of diabetes compared with standard doses," Professor Kausik Ray of St George's said.

He said for every 498 patients treated there was one extra case of diabetes. But use of high-dose statins reduced risk of heart attacks, strokes, and the need for revascularisation by 16%.

For every 155 people treated, one of these heart problems was prevented, the team reported.

"Nobody should stop taking their prescribed statins because of the evidence shown in this research," said Professor Peter Weissberg of the British Heart Foundation, who was not involved with the study.

"Statins play a vital role in protecting the hearts of many, many people and the benefits still far outweigh any risks associated with diabetes," he said.

High risks

"Patients who need high doses of statins are at very high risk of heart attacks and strokes. They should not come off these drugs, but simply be monitored more closely," Ray said.

The team also compared rates of heart problems in people who took high doses of Zocor, available widely as the generic simvastatin and less costly than brand-name Lipitor (atorvastatin).

The risk of developing diabetes proved to be the same with both drugs. But high-dose Lipitor cut the risk of heart attacks and strokes by 22%, compared with a 5% reduction in heart risk among those who took simvastatin, Ray said.

He said the study shows high-dose simvastatin is not the best option.

"The net benefit of simvastatin is clearly very low and patients on simvastatin 80 mg should be moved to atorvastatin 80 mg instead," Ray said. "I don't think we can wait for loss of (Lipitor's) patent to stop using simvastatin 80 mg," Ray said.

Currently, the National Institute for Health and Clinical Excellence, Britain's health cost watchdog, recommends an 80 mg dose of simvastatin because it is the least costly option for patients with heart disease.

US health regulators earlier this month recommended limiting the 80 mg dose of simvastatin because it increases the risk of muscle damage.

An estimated 2.1 million patients in the United States were prescribed a product containing 80mg of simvastatin in 2010, according to the US Food and Drug Administration.

(Reuters Health, Julie Steenhuysen, June 2011)

Read more:

Types of strokes

Type 1 diabetes

Type 2 diabetes

We live in a world where facts and fiction get blurred
In times of uncertainty you need journalism you can trust. For only R75 per month, you have access to a world of in-depth analyses, investigative journalism, top opinions and a range of features. Journalism strengthens democracy. Invest in the future today.
Subscribe to News24
Voting Booth
Have you entered our Health of the Nation survey?
Please select an option Oops! Something went wrong, please try again later.
29% - 9758 votes
71% - 24094 votes