Maggie came hot-foot from a “health check” where she’d had her cholesterol measured. “Six point two!” she told me. “The nurse said that’s high.” She sounded rather spooked. “I’d like you to give me a statin.”
I’ve known Maggie for years. She’s a sensible academic in her early fifties. She’d done enough googling to learn that a “high” cholesterol means you are “at risk” of cardiovascular disease (CVD) – heart attacks and strokes – and that statins lower cholesterol and reduce CVD risk by 25 per cent. Her request for treatment made perfect sense to her . . . except she had fallen for the same myth that leads to several million people in the UK swallowing a statin every day for no good reason at all.
Focus for a moment on that 25 per cent risk reduction. If you’re at high risk of something nasty, then lopping off a quarter of that risk makes sense. The people at greatest risk of heart attacks and strokes are those who have previously suffered one. Giving statins to these patients (secondary prevention) does convey modest benefits. If you take 100 heart attack survivors and get them to take a statin for five years, you’ll save one life, prevent two or three non-fatal heart attacks, and avert one stroke. That is worthwhile, even if the statins will fail to prevent at least 15 other heart attacks/strokes, and will cause two patients to develop diabetes, and provoke muscle weakness in ten others. Notice, though: 95 per cent of these highest-risk patients will derive absolutely no benefit from their five years of statin consumption.
Come back to Maggie. Using a statin on someone without existing CVD is termed primary prevention. Maggie has no other risk factors (high blood pressure, smoking, diabetes, and so on) and so her chance of developing heart disease is very low. In Maggie’s case, because her risk is so small to start with, a 25 per cent reduction is minuscule and meaningless. You’d have to treat hundreds of Maggies for years on end to hope to make a jot of positive difference to one of them, and the side effects from statins (we’re still discovering what these are) will far outweigh any putative benefit.
There are large numbers of people just like Maggie who are taking statins and who should come off the tablets. But what about individuals at greater risk – people with high blood pressure or obesity, or smokers? Is there a level of risk at which primary prevention is worthwhile? For some time the UK’s National Institute for Health and Clinical Excellence (NICE) has suggested a threshold of 20 per cent risk over ten years.
At first glance, the trial data does suggest a marginal impact at this sort of level: roughly two heart attacks/strokes are averted among 100 people treated for five years. But, crucially, death rates are not altered; no lives are saved by using statins. This probably reflects the harm also caused by statins, and how any small reduction in CVD is negated by disability and death from other causes.
Taking up regular exercise, or adopting a Mediterranean diet, reduces CVD risk by degrees comparable with statins – in the case of diet, substantially more so. If someone smokes, quitting is similarly helpful. What’s more, once one has adopted these lifestyle changes, statins become virtually redundant. Lifestyle modification is also cheap; there are very few harms besides. And, unlike with statins, these measures protect against other causes of death and disability, such as cancer and the frailties of advancing age. Oh, and they’re good for mental health, too.
This February, NICE initiated a consultation on halving its primary prevention threshold to 10 per cent risk. If achieved, this would add hugely to the six million people in the UK who take statins on prescription. Rather than exacerbate our statin fetish, NICE could design simple decision aids that would help doctors understand the more effective improvements that lifestyle changes can bring to health and well-being – and which would illustrate these benefits to patients.
Once we’d talked things through, Maggie resolved to start attending the university gym a few times a week. She decided to forget the statin prescription, too. As a nation, we’d do well to try the same.