Do statin benefits outweigh risks?
From Dr J Thompson, Slough
Malcolm Kendrick declares that men will not live one day longer from taking statins (Clinical, 3 August).
Do statistics back him up?
In the most positive statin study so far, the 4S trial, the chance of surviving five years with and without a statin was 88.5 per cent and 91.8 per cent respectively – a gain of 3.3 per cent.
Other trials show lesser gains: 0.9 per cent in WOSCOPs, 0.78 per cent in CARE, 3 per cent in LIPID.
Two trials show increased mortality: 0.09 per cent in AFCAPS/TexCAPS and 0.3 per cent in EXCEL.
We could sum this up by saying statins give a smallish reduction of an already small risk.
So why have they become so popular? The real problem is misunderstanding of risk. GPs and the public alike are being given the relative risks rather than the absolute risks. For example, we often hear that statins reduce the risk of dying from heart disease by 10-30 per cent.
This is relative risk and it sounds impressive. However, it is quite misleading. To illustrate this you need to compare it with some simple lifestyle changes.
A large Dutch study showed drinking three cups of tea daily reduced the relative risk of heart disease by 30 per cent and another study showed that eating three meals of oily fish a week gave the same 30 per cent risk reduction.
Doubling the time exposed to daylight reduces the relative risk of heart disease by 50 per cent and eating a Mediterranean diet reduces the risk by 70 per cent.
It is essential also to compare the risks. These are negligible with lifestyle changes but large with drugs. Statins can cause peripheral neuropathy, global amnesia, sexual problems, myopathy and heart failure.
The biggest worry, however, is cancer. Animal studies have consistently shown increases in cancers with statins and this can be predicted from the ability of statins to reduce
co-enzyme Q10 which has a potent anti-cancer effect (see studies of K Lockwood ).
Five-year trials would be unlikely to show up cancer risks. In spite of this, increases in cancer have been found in some trials – especially skin cancers which typically show early.
Only time will give us the answer on the longer-term cancer risks.
A crucial question remains unanswered regarding statins: is the small absolute risk reduction in heart disease (in men only) outweighed by serious long-term side-effects in the increasingly large population taking these drugs?