Do statins increase your diabetes risk?

Statins tablets and a glass of water

Some news reports have suggested that if you take statins you are more likely to develop type 2 diabetes. We find out the truth behind the headlines.

24 October 2017

New research has suggested that statins can increase the risk of diabetes in those who are already at high risk.

The report has received widespread news coverage, although the link between statins and diabetes is not a new finding. And the researchers emphasised that this does not mean that you should stop taking statins if you’ve been prescribed them.

What’s new about this research is that it focused on people who are at high risk of diabetes. The researchers said that previous studies have used participants who were relatively low risk of diabetes. This new study, from Albert Einstein College of Medicine in New York, studied overweight people who already had raised blood sugar levels – a condition sometimes known as pre-diabetes.

The link between statins and diabetes is not a new finding

The report says: “For individual patients, a potential modest increase in diabetes risk clearly needs to be balanced against the consistent and highly significant reductions in heart attacks, strokes and cardiovascular death associated with statin treatment.”

Prof Jeremy Pearson, Associate Medical Director at the British Heart Foundation, said: “This study indicates that statins can increase the onset of diabetes in some people. However, it does not mean that people should stop taking their statins as there is no doubt they save lives. People who are prescribed statins should not worry, and should continue to take their statins as normal. They can speak to their GP or call the BHF’s Heart Helpline on 0300 330 3311 if they have any concerns.”

The research

The research, published in the British Medical Journal, used data from the Diabetes Prevention Program (DPP), where 27 clinical centres in the USA recruited a total of 3,234 people who were overweight and obese, and at a high risk of diabetes.

About 50 per cent of the participants were members of ethnic or racial minority groups and 20 per cent were aged 60 or above.

27 clinical centres in the USA recruited a total of 3,234 people who were overweight and obese, and at a high risk of diabetes

The research found that patients who had started taking statins during a 10-year follow up period had a risk of developing type 2 diabetes that was around a third higher than those who weren’t taking statins. The risk of diabetes appeared to increase if they took statins for longer.

The researchers found that diabetes risk did not differ whether people were on low or high potency statins.

The strengths of the research include a long follow-up and updated information about statin use every 6 months.

A potential weakness of the study is that it relied on patients to tell the researchers that they were taking medications (they were asked to bring prescription pill bottles to each research visit.)  A potentially more significant weakness is that the doctor’s decision to start a statin might have been linked to a patient’s future risk of diabetes. Professor Colin Baigent, Director of the MRC Population Health Research Unit at the University of Oxford, said: “This complicates calculations, and means that the increased diabetes risk of about one third is really quite unreliable.”

The biggest drawback in the study, and the reporting of it, is that it only shows relative risk.

The biggest drawback in the study, and the reporting of it, is that it only shows relative risk. So we know that for this high-risk group, their risk of diabetes increased by around a third. But to really understand how significant that is, we need to know what the level of risk is to start with, or in a given number of people, how many extra cases might be caused by taking statins. The study didn’t give this information.

The study was not able to look at whether the dose of statins affected diabetes risk.

Dr Tim Chico, Reader in Cardiovascular Medicine and consultant cardiologist at the University of Sheffield, said: “Both cardiovascular disease – such as heart attack and stroke – and type 2 diabetes are caused by a combination of lifestyle and genetic factors, and no single drug or behaviour will completely protect against them. Type 2 diabetes is largely caused by being overweight, and having a poor diet and a sedentary lifestyle, and more attention must be directed to addressing these issues in society. Statins play a major role in reducing cardiovascular disease in high risk patients, but all drugs have possible side effects and their risks and benefits need to be properly discussed between the doctor and the patient.”

The coverage

The research was covered in the Daily Mail, Pulse magazine, and ITV News, among others. The media coverage was overall well-balanced, was not unnecessarily scare-mongering, and included comments from experts who emphasised that it’s important to keep taking your statins. The only flaw in the news coverage is that it didn’t necessarily make the limitations of the research clear.

  • If you feel concerned by this research, you can call the BHF’s Heart Helpline on 0300 330 3311.

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