Statins  Kidney

Statins could cause liver and kidney problems, research shows

New UK data highlights range of possible problems associated with cholesterol-lowering drugs

Cholesterol-lowering drugs taken by millions of Britons could cause liver, kidney, muscle and eye problems, research out today suggests.

Statins are used to treat people with high cholesterol and to cut the chances of heart disease or stroke in those at high risk, such as diabetics and people with angina.

According to the British Heart Foundation, four million people in Britain take the drugs. Some side-effects from the drugs are already known but new UK data has highlighted a range of other possible problems.

The study found that some statins can lead to an increased risk of liver dysfunction, acute kidney failure, muscle damage known as myopathy and cataracts.

Side-effects that are already known include insomnia, constipation or diarrhoea, headaches, loss of appetite and loss of sensation or pain in the nerve endings of the hands and feet. Nevertheless, experts and charity figures said the benefits of statins – such as saving lives from heart disease – still outweigh the risks.

Today's research, published in the British Medical Journal (BMJ), involved analysing data from 368 GP practices.

The study involved more than two million patients in England and Wales aged 30 to 84, of whom 225,922 (10.7%) were new users of statins, 159,790 (70.7%) were prescribed simvastatin, 50,328 (22.3%) atorvastatin, 8,103 (3.6%) pravastatin, 4,497 (1.9%) rosuvastatin and 3,204 (1.4%) fluvastatin.

Their health from 2002 to 2008 was analysed by experts from the University of Nottingham.

The results showed that statins were linked to a decreased risk of oesophageal cancer but increased risk of moderate or serious liver dysfunction, acute renal failure, moderate or serious myopathy and cataracts.

There was no evidence of statins being linked to a range of other cancers or Parkinson's disease.

The authors wrote: "Adverse effects were similar across statin types for each outcome except liver dysfunction where risks were highest for fluvastatin."

The authors said the higher the dose of a statin, the more at risk a patient was from acute renal failure and liver dysfunction.

"All increased risks persisted during treatment and were highest in the first year," they added.

The authors estimated the number of extra cases of a side-effect that could be expected for each 10,000 patients treated with statins.

For high-risk females, there would be 271 fewer cases of heart disease and eight fewer cases of oesophageal cancer but 74 extra patients who experience liver dysfunction, 23 extra patients with acute renal failure, 307 extra patients with cataracts and 39 extra with myopathy.

The figures for high-risk males were similar, except for myopathy, with an extra 110 cases.

In medium-risk women, there would be 228 fewer cases of heart disease and seven of oesophageal cancer, but 17 extra cases of renal failure, 252 of cataracts, 65 of liver dysfunction and 32 of myopathy.

Figures for medium-risk men were similar, except for myopathy which was higher.

The authors acknowledged that some of the effects might be due to better detection rates since patients taking statins will consult their doctor more.

They said statins cut the risk of heart disease but called for more research so people at risk of side-effects could be closely monitored.

In an accompanying editorial, two experts from the US and United Arab Emirates said: "When used according to current guidelines, the benefits of statins outweigh their risks."

June Davison, cardiac nurse at the British Heart Foundation, added: "We already know that a small number of people taking statins experience unwanted side-effects.

"However for people with, or at high risk of heart disease, the benefits of statins far outweigh this risk.

"The good news is that the researchers found no significant link between the use of statins and risk of Parkinson's disease or many cancers.

"Anybody experiencing side effects while taking statins should speak to their doctor."

Earlier this year, an American study found that high doses of simvastatin can cause muscle damage and a rare condition which induces kidney problems.