The January 2012 issue of Drug Safety Update from the MHRA features an article summarising new evidence relating to the risk of hyperglycaemia and diabetes in patients taking statin therapy, and the practical implications of this.

A meta-analysis reported in 2010 found that statin therapy was associated with a slightly increased risk of new-onset diabetes (NOD), and it was estimated that treatment of 255 (95% CI 150–852) patients with statins for 4 years resulted in one extra case of diabetes (this risk however appears to depend markedly on individual risk factors, for example history of hypertension, raised triglycerides, and raised body mass index at baseline).  The report notes a number of limitations of comparing studies across the statin class.

The report notes that statin use may be associated with a level of hyperglycaemia in some patients where formal diabetes care is appropriate. Although the level of risk of NOD may vary between statins, there is insufficient evidence to confirm or exclude an increased risk for any member of the statin class. The risk appears to be mainly in patients already at increased risk of developing diabetes (raised fasting blood glucose at baseline).

However, the overall benefits of statins strongly outweigh any risks, including in those at risk of developing diabetes or those with pre-existing diabetes, and this is therefore not a reason for stopping statin treatment.  Please see the link below for further details.