Statin therapy increases the risk of diabetes, a systematic review of randomised, placebo controlled trials has confirmed but many of the other side-effects reported were similar with placebo.

The researchers identified a total of 29 randomised controlled trials that compared a statin with placebo for the prevention of cardiovascular events (in both primary and secondary prevention) and that also reported side effects separately in the two arms.

In the 14 primary prevention trials, covering 46,262 patients, statin therapy:

• increased the absolute risk of developing diabetes by 0.5% (95% CI:0.1 to 1.0%, P = 0.012)

• reduced the risk of death by 0.5% (95% CI: -0.9 to -0.2%, P = 0.003)

In the 15 secondary prevention trials, which included 37,618 patients, statins:
• reduced the risk of death by 1.4% (95% CI: -2.1 to -0.7%, P < 0.001)

There were no other statin-attributable symptoms, although asymptomatic liver transaminase elevation was slightly more frequent (0.4%) with statins across all trials. This was mainly attributable to higher dose statins. Serious adverse events and withdrawals were similar in both arms.

Only the development of diabetes mellitus was significantly higher on statins compared with placebo, with one in five new cases directly attributed to the drugs.

The authors conclude that only a small minority of symptoms reported on statins are genuinely caused by the drugs and that almost all of these would occur just as frequently on placebo. They also acknowledge that not all statins, nor all doses, could be addressed by the meta-analysis.

The eligible placebo-controlled trials tended to be of relatively low-strength statin regimens.

Statins are a vital part of the pharmacological management of cardiovascular disease and are generally well tolerated but it is not that unusual to be faced with a patient in primary care who feels disinclined to continue with these drugs because of a perceived adverse reaction or intolerance. This often results in switching of drugs and can lead to abandonment of the class altogether.

I think the message for our patients is that these drugs are unlikely to cause significant side effects and in secondary prevention in particular they have much to offer in prognostic gains.

Dr Peter Savill

• Finegold JA, Manisty CH, Goldacre B et al. What proportion of symptomatic side effects in patients taking statins are genuinely caused by the drug? Systematic review of randomised placebo-controlled trials to aid individual patient choice. Eur J Prev Cardiol 2014; 21(4):464-74