GPs should choose statin carefully in patients at high risk of diabetes, study suggests
Potent statins increase the risk of diabetes by 10% to 20% compared with pravastatin, a new study suggests.
The population-based study of nearly half a million elderly statin users found the risk of incident diabetes over five years was 10% to 20% higher among people taking atorvastatin, rosuvastatin or simvastatin compared with patients taking pravastatin.
The potential risk of diabetes with statin use has been the subject of much debate, with all three of these relatively potent drugs previously linked to the development of diabetes compared with placebo. In contrast, pravastatin has been associated with a lowered risk of diabetes.
For the present Canadian study, researchers analysed diabetes rates among 471,250 patients (median aged 73 years) with no previous history of diabetes who were newly treated with a statin between August 1997 and the end of March 2010. Roughly half were taking them for primary prevention, the other half for secondary prevention.
The team found the absolute risk for incident diabetes was highest among those taking atorvastatin and rosuvastatin, at rates of 31 and 34 events per 1,000 person-years, respectively, while it was lower for simvastatin, at 26 outcomes per 1,000 person-years and with pravastatin, at 23 outcomes per 1,000 person-years.
Relative to pravastatin users, this meant patients on atorvastatin had a 22% increased relative risk of developing diabetes, while rosuvastatin users had an 18% increased risk and simvastatin users a 10% increased risk.
The potency of statins - in increasing order is fluvastatin, lovastatin, pravastatin, simvastatin, atorvastatin and rosuvastatin. The researchers found no difference in risk of diabetes with either fluvastatin or lovastatin in comparison with pravastatin. Lovastatin is not licensed for use in the UK.
The researchers say the findings held true for both primary and secondary prevention groups. Overall, moderate and high doses of statins were associated with higher incidences of diabetes than low doses, while rosuvastatin appeared risky only at higher doses.
The researchers concluded: ‘Preferential use of pravastatin, and potentially fluvastatin or lovastatin, while recognizing the limited efficacy data and increased risk of drug interactions with these two agents, might be warranted.
‘Pravastatin might have a preferential benefit among primary prevention patients at high risk of diabetes.’
High-profile statin critic Dr Malcolm Kendrick, a GP in Macclesfield, who believes the side effects of statins have been overlooked said: ‘The analysis is essentially correct. It is now well known that statins greatly increase the risk of diabetes, an effect first widely publicised after the JUPITER trial.
‘It is a direct effect of reducing co-enzyme Q 10 in the beta cells of the pancreas.’