Women on statins, the anti-cholesterol drugs, are at risk of fatigue, a U.S. study has found.
Two in five women taking the pills had less energy than before, with one in ten reporting they felt ‘much worse’.
While experts stress that patients should never stop taking their pills before speaking with their doctor, it has been suggested that for some women, this side-effect could outweigh the benefits of the drug.
This news comes on top of previous research that suggested women may not benefit from statins as much as men.
So should women carry on taking the pills? We asked the experts...
WHY DO I NEED STATINS?
Statins reduce the amount of LDL (‘bad’) cholesterol, which can lead to hardening and narrowing of the arteries, raising the risk of heart disease, heart attack and stroke.
Statins are recommended for those with heart disease or a high risk of developing it.
Around five million Britons are taking statins, though last month, a review by researchers at the University of Oxford said everyone over 50 could benefit from them.
WHAT DOES THE NEW RESEARCH SAY?
The new study into fatigue involved two leading statins, pravastatin and simvastatin.
The researchers at UC San Diego School of Medicine looked at more than 1,000 adults, a third of them women, and the effects of statins on energy levels and exercise capacity.
Participants were randomly given a placebo or a statin at an average dose — pravastatin (40mg) or simvastatin (20mg).
The effect appeared to be stronger for simvastatin.
CAN STATINS CAUSE FATIGUE?
Most people think cholesterol comes from our diets — in fact, most is made in the liver.
Statins work by blocking enzymes involved in the production of cholesterol.
However, many hormones, including oestrogen, are also metabolised by the liver and it’s thought statins may interfere with this, says Dr Sovra Whitcroft, a gynaecologist at the Surrey Park Clinic in Guildford.
‘As oestrogen promotes sleep, any disruption to its levels could lead to tiredness.’
ANY OTHER SIDE-EFFECTS?
The list of officially acknowledged side-effects has grown. Initially these included upset stomach, headache or insomnia. Memory problems were added in 2009.
However, GPs point to other side-effects such as irritability and ‘generally feeling old’ that are never mentioned in studies, yet are common.
Another concern is hair loss.
Dr David Fenton, a consultant dermatologist in London, says this is a rare side-effect he has witnessed.
‘Women shed more hair than they should, and it can exacerbate any genetic tendency towards the female equivalent of male pattern baldness. I see many with thinning patches.’
A recent Greek study, published in the International Journal of Cardiology, suggested up to 10 per cent of patients reported myopathy — muscle pain.
‘There has not been a post-marketing surveillance study of statins,’ says Dr Malcolm Kendrick, a Cheshire GP and author of The Great Cholesterol Con.
‘So no one really knows what the adverse effects may be or how many people experience them.
‘Some say side-effects are vanishingly rare. But many patients I see have probable side-effects from a statin with a significant impact on their quality of life.’
And many experts agree women seem to suffer more side-effects than men.
Dr Richard Karas of Tufts University Medical Center in Boston, U.S., says because women are smaller and tend to be older when prescribed statins, this might contribute.
However, the British Heart Foundation reports only one in every 10,000 people who take statins will experience a potentially dangerous side-effect.
The NHS estimates statins save 7,000 lives a year, so the risks are seen to be outweighed by the benefits.
SO DO STATINS WORK ON WOMEN?
It's generally accepted that for people who have had a heart attack, stroke, or have heart disease, statins can be a life-saver.
But more controversial is whether women benefit in the same way as men.
When it comes to preventing another stroke or heart attack (known as ‘secondary prevention’), a key study, the Jupiter trial, found that taking rosuvastatin cut the recurrence rate in men and women.
As Kausik Ray, professor of cardiovascular disease prevention at St George’s University, London, points out, the five-year study ‘was so successful at reducing the incidence of deaths it was stopped after two years’.
‘It found that healthy women at risk of heart attacks benefited significantly as much as men from taking statins.’
However, Dr Kendrick points out that while the recurrence rate dropped for both genders, the death rate dropped only for men.
As well as preventing a second heart attack or stroke, statins are also increasingly being used as ‘primary prevention’ — before there’s any sign of heart disease, let alone a symptom such as angina or a heart attack.
Here, the picture about the benefits for women is less clear.
A major review by the Cochrane Library (a highly regarded research organisation) said there was no evidence for using statins for primary prevention unless the patient was deemed at high risk of cardiovascular problems.
The review also pointed out most of the trials were conducted on white, middle-aged men.
So we can’t necessarily assume the findings will apply to older people, who may be at greater risk of adverse effects, and women, who may be at lower cardiovascular risk (thanks to their better lifestyles, oestrogen — which protects the heart — and their naturally higher levels of ‘good’ cholesterol).
For instance, when researchers from Harvard Medical School re-analysed eight major studies in 2007, they concluded there was no evidence statins worked as primary prevention for women.
‘My view is that statins are, for women, completely useless for primary and secondary prevention,’ says Dr Kendrick.
However, Professor Ray disagrees, pointing out that in the Jupiter trial, which was published in the New England Journal of Medicine, 40 per cent of the nearly 18,000 participants were women.
‘The evidence clearly shows that women at risk of heart disease benefit to a similar extent as men, though the number of women in trials is small,’ he says.
I’M TIRED. SHOULD I GIVE UP STATINS?
‘It's difficult to monitor fatigue — you can’t measure it like cholesterol,’ says Professor Ray.
‘The latest study is useful, but it is not going to change what we do.
‘Fatigue is a common symptom, especially in women, but can be due to other causes.
For example, you may have an underactive thyroid and in premenopausal women fatigue could be related to anaemia. These conditions are often not picked up.’
Dermatologist Dr Fenton points out that tiredness could also be a side-effect of the lifestyle measures many implement when prescribed statins.
‘Losing weight, taking up exercise and restricting a diet by eating less red meat can all cause tiredness. It’s vital to check iron levels.’
Even if the fatigue is linked to statins, don’t stop taking the drug automatically, especially if you’re at high risk for future events, e.g., you are diabetic.
‘If you have a strong family history of heart disease, and a poor lifestyle, or have multiple risk factors, putting up with fatigue may be more sensible than being at risk of heart attack,’ says Professor Ray.
‘You need to discuss this with your GP.’
COULD I SWAP TO ANOTHER STATIN?
‘You can certainly try taking them in a different way,’ says Professor Ray.
‘For example, I’d recommend you take a drug holiday, under medical supervision. Stop taking your statin for a week (which is how long it will take to clear your system) and then see how you feel.’
‘Or you could ask to be swapped to a long-acting statin, such as rosuvastatin, a 5mg twice-weekly tablet, which may suit your body’s digestion.’
Statins have been linked to low levels of co-enzyme Q10 — a natural compound found in cells which is important for turning glucose into energy.
‘This may cause tiredness, but you can’t measure levels in the body, so you can only see if taking a supplement helps by trial and error.
'It can’t hurt and might help,’ says Professor Ray.