Some statins, drugs taken to protect the heart, may increase the risk of developing type-2 diabetes, according to researchers in Canada.
Their study of 1.5 million people, in the British Medical Journal, suggested powerful statins could increase the risk by 22% compared with weaker drugs.
Atorvastatin was linked to one extra case of diabetes for every 160 patients treated.
Experts said the benefits of statins still outweighed any risks.
Powerful statins increase type 2 diabetes risk by 22 percent
Statins are a group of commonly prescribed drugs that lower the levels of bad cholesterol in the blood. This reduces the chances of a heart attack or stroke.
A team of researchers from hospitals in Toronto said there had been controversy around the risk of diabetes with different statins.
They looked at medical records of 1.5 million people over the age of 66 and compared the incidence of diabetes between people taking different statins.
Their report said: “We found that patients treated with atorvastatin, rosuvastatin, or simvastatin were at increased risk of new onset diabetes compared with those treated with pravastatin.
“Clinicians should consider this risk when they are contemplating statin treatment for individual patients.
“Preferential use of pravastatin… might be warranted.”
Commenting on the study, Prof. Risto Huupponen and Prof. Jorma Viikari, from the University of Turku, in Finland, said: “The overall benefit of statins still clearly outweighs the potential risk of diabetes.”
However, they said, the different statins should be targeted at the right patients.
They said: “The most potent statins, at least in higher doses, should preferably be reserved for patients who do not respond to low-potency treatment, but have a high total risk of cardiovascular disease.”
A new study suggests that an “early and aggressive” approach to people on the cusp of developing Type 2 diabetes is justified to reduce cases of the disease.
People with “pre-diabetes” have higher than normal blood sugar which has not yet reached diabetic levels.
A US study, published in the Lancet, showed restoring normal sugar levels more than halved the numbers going on to Type 2 diabetes.
Experts said the findings were clinically important.
It is thought that 7 million people have pre-diabetes in the UK and 79 million in the US. They are at heightened risk of Type 2 diabetes, heart attack and stroke. Many are undiagnosed.
A new study suggests that an "early and aggressive" approach to people on the cusp of developing Type 2 diabetes is justified to reduce cases of the disease
Some measures, such as weight loss and more exercise, can reverse pre-diabetes. The study, by the US Diabetes Prevention Program Research Group, tried to determine how effective the treatment was at preventing Type 2 diabetes.
It followed 1,990 people with pre-diabetes. Some were being treated through drugs or lifestyle change, others were not.
It showed patients who reduced their blood sugar levels to normal, even briefly, were 56% less likely to develop Type 2 diabetes during the six years of the study.
Lead author Dr. Leigh Perreault, from the University of Colorado, said: “This analysis draws attention to the significant long-term reduction in diabetes risk when someone with pre-diabetes returns to normal glucose regulation, supporting a shift in the standard of care to early and aggressive glucose-lowering treatment in patients at highest risk.”
Dr. Natalia Yakubovich, from McMaster University in Ontario, Canada, said the “findings clearly suggest” that restoring normal blood sugar levels was “of clinical relevance”.
She added: “Identification of regression to normal glucose regulation could be an important way to stratify people into those at higher and lower risk of progression to diabetes.
“Such stratification could therefore identify individuals for whom additional treatment might be needed to prevent diabetes or to slow down disease progression.”