Stronger Statin Doses Tied To Kidney Injury

A new study finds that high potency statins are tied to higher risk of being hospitalized for acute kidney injury compared with less potent statins and that the risk persists for two years.

Lead researcher Colin Dormuth, of the University of British Columbia, in Vancouver, Canada, and colleagues, write about their findings in a BMJ paper that was published online on 19 March.

Statins are a widely-used class of drug for lowering cholesterol as a way to reduce the risk of cardiovascular disease, with higher doses prescribed for those at higher risk.

Largely as a result of clinical trials showing improved cardiovascular outcomes, there has been a trend toward increasing the potency of statins, either with larger doses, such as simvastatin or atorvastatin 40-80 mg, or with the more potent form, rosuvastatin.

But researchers are beginning to suggest that increasing potency may lead to adverse kidney problems, and because statins are so widely used, concerns are being raised about these adverse events.

Clinical trials don't involve large numbers of people, so adverse side effects may not be common enough to be identified, and it is only in postmarketing monitoring, and analyses of large groups of patients, that they begin to show.

For this latest study, researchers from across Canada compared patients who were prescribed high potency statins to those who were prescribed low potency statins in seven Canadian provinces and two international databases (UK and US) between 1997 and 2008.

They used the health records of 2 million people from the Canadian Network for Observational Drug Effect Studies (CNODES) to assess the link between treatment with high versus low potency statins and hospitalization for acute kidney injury in patients with and without chronic kidney disease.

All patients were age 40 and over: the average age was 68.

High potency was defined as rosuvastatin at doses of 10mg or higher, atorvastatin at doses of 20mg or higher, and simvastatin at doses of 40mg or higher. All others were defined as low potency.

When they analyzed the data, the researchers found that high potency statin users were 34% more likely to be hospitalized for acute kidney injury compared with low potency statin users in the first 120 days of treatment.

And the risk remained higher for two years after starting treatment.

Rates were not significantly increased in patients with chronic kidney disease.

Expressing the results in another way, the researchers estimate that for every 1,700 patients without chronic kidney disease treated with a high potency as opposed to a low potency statin, there is one additional hospitalization for acute kidney injury.

Although they suggest clinicians take this apparent elevated risk into account when low potency statins are an option, the researchers also recommend further studies be done to look more closely at the links between statin use and kidney injury.

In an editorial, Robert G Fassett and Jeff S Coombes, professors at the University of Queensland Australia, also call for further studies, particularly comparing the effects of strong and weak statin doses.

And they say more research is needed on the various causes of acute kidney injuries that lead to hospitalization.

A Danish study published in 2012 found that statins were tied to reduced cancer deaths: people who regularly used statins to lower cholesterol and then received a cancer diagnosis were 15% less likely to die from cancer or any other cause.