LONDON (Reuters) - People on cholesterol-lowering statins are 9 percent more likely to develop diabetes, but this small absolute risk is outweighed by the drugs’ heart-protecting properties, researchers said on Wednesday.
The finding is unlikely to dent the use of best-selling pills like Pfizer Inc’s Lipitor and AstraZeneca Plc’s Crestor by the majority of patients.
It could, however, prompt a rethink among those with low cardiovascular risk factors who are tempted to take statins to prevent future heart disease.
Statins are among the most successful drugs of all time and have been credited with preventing millions of heart attacks and strokes. They generally have few adverse side effects.
Experts said the latest finding, published in the Lancet medical journal, should not stop patients at moderate or high heart risk from taking statins. But it could deter a headlong rush to use them even more widely.
“It will stop us putting statins in the water, as it were, and mean we give them when appropriate for the right reasons,” lead researcher Naveed Sattar of the Glasgow Cardiovascular Research Center at the University of Glasgow told Reuters.
Past trials of statins have produced conflicting results, with some — including an influential study of Crestor in 2008 — suggesting they may cause type 2 diabetes, but others pointing to an actual reduction in risk.
To resolve the issue, Sattar and colleagues carried out what is known as a meta-analysis, reviewing data from 13 large randomised controlled trials of statins between 1994 and 2009, involving more than 91,000 patients.
The result showed a clear statin-diabetes link, which researchers said was unlikely to be a chance finding. But the effect was slight and treating 255 patients with statins for four years would result in only one extra case of diabetes.
For comparison, the researchers estimated that giving statins to the same group would avoid 5.4 deaths or heart attacks over four years, and nearly the same number of strokes or artery-opening procedures would also be avoided.
“Whilst a new risk of statins has been identified, the risk seems small and far outweighed by the benefits of this life-saving class of drugs,” Christopher Cannon of Boston’s Brigham and Women’s Hospital and Harvard Medical School said in an accompanying commentary.
Sattar said the effect appeared to be common to all drugs in the statin class, although whether some may be more detrimental than others required further research.
The diabetes finding contrasts with that of cancer, where another meta-analysis two years ago concluded statins neither caused nor prevented the disease.
Just why statins should be linked to diabetes risk is unclear and cannot be explained by the fact that people on the drugs live slightly longer.
Sattar said the fact that statins cut bad cholesterol, improved blood vessel function and dampened inflammation made the link surprising. But he noted they also affected the liver and muscles, which seemed to tip the balance.
Editing by Rupert Winchester