The latest research was led by a team from University College London and the University of Glasgow and was published in The Lancet. It looked at genetic data from 223,463 people, and from 129,170 people who had taken part in clinical trials that tested the effect of statins on heart disease and stroke.
The new study shows that people prescribed statins rather than placebo medication had about a 12% greater risk of getting type 2 diabetes over a 4-year period, and also gained about half a pound in weight on average.
Co-author Dr. David Preiss of the University of Glasgow Institute of Cardiovascular and Medical Sciences says in a statement: "Weight gain is a risk factor for diabetes, which might help explain the small increased risk of diabetes observed in people taking statins."
Commenting on the findings in a statement, Jeremy Pearson, PhD, associate medical director at the British Heart Foundation, which helped fund the study, says: "Statins offer substantial protection from coronary heart disease. This rigorous and extensive study looked at why people taking them have a small increased risk of diabetes.
"The researchers found a direct relationship between how statins reduce cholesterol production and small increases in weight gain and blood sugar. This could explain the slightly increased risk of diabetes – a risk that could be reduced through lifestyle changes.
"This study should reassure people that the benefits of taking statins far outweigh the small effect on diabetes risk. But the results also reinforce that, alongside prescribed medication, taking steps to maintain a healthy weight is essential to stay heart healthy."