Statins for Lowering High Cholesterol
Statins Used to Lower LDL Cholesterol Levels
Although high cholesterol levels are often said to be a risk factor for heart disease, what is actually meant is that high levels of Low Density Lipoprotein (LDL) cholesterol, which is sometimes referred to as “bad” cholesterol, may be associated with an increased risk of heart disease. High levels of High Density Lipoprotein (HDL) cholesterol (or “good” cholesterol) are actually associated with heart health.
If you have a cholesterol test (a blood test taken after fasting for 12 hours) then the analysis will look at the total level of cholesterol, the HDL and LDL levels and also the ratio between the total cholesterol and the HDL cholesterol. If the results of your cholesterol test show that you have a high level of LDL cholesterol (or a low level of HDL cholesterol), then it may be considered appropriate to take action to get your levels in line with the levels recommended by current guidelines.
Pretty well everyone agrees that the best way of improving your cholesterol balance (and more importantly, your heart health) is through lifestyle changes, such as stopping smoking, improving your diet, losing weight if you are overweight and exercising more and of course these changes offer many, many other benefits as well.
However in some cases these changes may not be enough to get your cholesterol to what is currently recommended to be a healthy level and this is where cholesterol treating drugs may have a role to play.
The most common pharmaceutical approach to altering cholesterol levels is to use drugs that lower LDL cholesterol, but drugs that help to increase HDL may be prescribed for people who have a low HDL level.
A class of drugs called statins are the most commonly prescribed treatment to try to reduce LDL cholesterol.
Treating High LDL Cholesterol Levels with Statins
Statins work by inhibiting the production of an enzyme which plays an important role in the production of cholesterol in the liver (one of the main organs of the body where cholesterol is produced, although it is also produced in the intestines, adrenal glands and reproductive organs).
Cholesterol present in foods made from animal products (it is not found in plant products) contributes only a relatively small amount of the total cholesterol found in the body. The body actually manufactures most of its cholesterol from the so called “bad fats” (saturated, hydrogenated and trans fats) and carbohydrates (especially processed carbohydrates) in our diet.
Inhibiting the body’s manufacture of cholesterol can therefore have a significant impact on overall cholesterol levels. Some studies have shown that the use of statins can reduce LDL by 1.8 mmol/l (70 mg/dl) which, with long term use, may result in a 60% decrease in heart attacks and sudden cardiac deaths and a 17% reduced risk of strokes.
These figures sound impressive, but there are many respected doctors and scientists who dispute these findings. They say that, when you look at the studies close up, the evidence shows that statins may only work for people who already have cardiovascular disease and that even in these people the reduced risk of dying from their heart conditions that comes with on-going statin treatment is negated by the increased risk of dying from other causes due to statin use. In other words, they argue, statins produce no overall reduction in the numbers of deaths. One study in Sweden showed that only people with the very highest cholesterol levels (in the top 5%) showed any benefit from reducing their cholesterol levels.
Furthermore, most of the studies that support the benefits of statins are under taken by the drug companies themselves and the figures are therefore presented in the way that makes them seem most effective at treating conditions. Looking carefully at the figures, even those produced by the drug companies themselves, can be a real eye opener.
In an advert for Lipitor, the worldwide top selling statin, the manufacturers claimed that Lipitor reduces the risk of heart attack by 36%, which certainly makes it sound like a drug that offers significant health benefits. In the small print of the ad, however, was also the information that in a large clinical study of individuals with multiple risk factors 3% of individuals in the control group (those taking a placebo or sugar pill) had a heart attack whereas in the group taking Lipitor 2% had a heart attack.
In other words where you would expect that 3 in every 100 people in this high risk category would have a heart attack, then 1 of them might not have a heart attack if taking Lipitor, but of course you can’t predict which one, so all 100 of them would have to take a drug which might offer real benefit to 1 of them, but put all of them at risk of serious side effects.
In addition to this, it is generally appropriate to allow for a margin of error in these trials. Taking this into account, the benefit offered by statin treatment may be considered to be insignificant. Indeed the only large clinical trial of statins funded by the US government found that there was no significant benefit.
If you want to try and understand how effective any drug is likely to be, there is a measure that you should be aware of called NNT, which stands for Number Needed to Treat. What this figure represents is the number of people who need to be treated by a drug for 1 person to benefit. So for Lipitor, the number needed to treat is 100 when taken over 3 1/3 years. Or, to put it another way, there is a 99% failure rate for Lipitor, even when the individuals being treated have been assessed as being as very high risk patients.
The success rate falls even further if you consider lower risk patients. For them the NNT is 250 when the drug is taken for 5 years – so 250 people have to be treated with this drug for 5 years for just 1 of them to see any benefit.
Compare this with the effectiveness of paracetamol in relieving post-operative pain by at least 50%, where the NNT is 3.6, or in other words for every 100 patients treated with paracetamol after an operation, 36 of them had at least a 50% reduction of their pain. To put it in its most simple terms: the lower the NNT, the more effective the treatment.
Bandolier, a respected independent journal about evidence-based healthcare, written by Oxford scientists, suggests that effective treatments usually have an NNT of between 2 and 4, although the NNT may be even lower than this for some antibiotics.
In addition to the rather unimpressive statistics for statins ability to make patients better, some experts argue that total cholesterol levels, or even high LDL levels may not actually be the major culprit in causing heart problems.
Currently it is widely accepted that high LDL cholesterol is a bad thing, but some studies have shown however that the correlation between high cholesterol and heart disease is not straight forward.
There is evidence that shows that some countries where the general population have much higher cholesterol levels than those found in the US, but also have significantly lower levels of heart disease. Similarly, some populations which typically have lower levels of cholesterol than found in the population of the US nonetheless have a higher incidence of heart disease.
Some scientists believe that cholesterol is not the cause of damage to the cardiovascular system, rather its presence is as a consequence of the damage that has occurred, as cholesterol plays an important part in the body’s healing mechanism and is a significant component in scar tissue.
(The evidence linking cholesterol levels to heart disease is examined in another article, which also looks in more detail at the alternative theories of why cholesterol levels may be higher in individuals with cardiovascular disease and what might actually be the cause of heart problems.)
It is also argued that if cholesterol were really a major culprit in causing (or increasing the risk of) heart disease, then statins would be more effective at reducing/preventing cardiac events, as they have been shown to be very good at decreasing LDL levels.
Even though some evidence does exist to suggest that statins may help to reduce the risk of heart attack (or further heart attacks) in men who already have cardiovascular disease, recent research suggests that this may not be as a result of their cholesterol lowering properties, but rather because they reduce the amount of an enzyme called Rho-kinase. Reducing this chemical reduces inflammation in arteries and studies in rats have shown that reducing the level of this enzyme in their bodies prevents them from getting heart disease.
There have been studies that show that there is a small decrease in the numbers of cardiac deaths occurring among groups of patients taking statins, when compared against a control group taking a placebo. What is sometimes not highlighted however is the fact that overall mortality rates in both groups were the same, with an increased incidence of deaths due to cancer in the group taking statins.
Generic & Brand Names of Statins
Whether or not they are safe and effective at treating or preventing heart conditions, there are a variety of statin medications, manufactured by different pharmaceutical companies. All of these drugs work in pretty much the same way, although their constituents vary somewhat, for example some statin drugs are fermented from plants which naturally contain statins, such as oyster mushrooms and red yeast rice, whilst other statin drugs are synthetic.
Statin drugs that are commonly prescribed include:
Atorvastatin – brand names: Lipitor and Torvast
Fluvastatin – brand names: Lescol and Lescol XL
Lovastatin – brand names: Mevacor, Altocor, Altoprev
Mevastatin
Pitivastatin – brand names: Pitiva and Livalo
Pravastatin – brand names: Pravachol, Selektine and Lipostat
Rosuvastatin – brand name: Crestor
Simvastatin – brand names: Zocor and Lipex
Simvastatin+Ezetimibe – brand name: Vytorin and Inegy
Lovastatin+Niacin extended-release – brand name: Advicor
Atorvastatin+Amlodipine Besylate – brand name: Caduet
Simvastatin+Niacin extended-release – brand name: Simcor
People Likely to be Prescribed Statins
Statins will usually be recommended to people who have cardiovascular disease and those who have had a heart attack, a stroke or TIA (Transient Ischemic Attack – sometimes known as a mini-stroke – causing brain dysfunction for less than 24 hours.) There is some evidence to show that statins can help to lower the risk of these conditions worsening.
Statins may also be prescribed for individuals considered to be at high risk of developing cardio vascular disease. This preventative approach is controversial, with some studies indicating that it is effective and others concluding it is not. There is certainly data to strongly suggest that statin treatment does not offer benefits to women or the over 65s. Also, use of some statins is also associated with a slightly increased risk of diabetes, which is itself associated with an increased risk of heart disease.
People considering taking statins should also be aware that, although these drugs are often described as “well tolerated” there are a number of different side effects that may be experienced, some of which can be extremely serious, even fatal.
These side effects arise as a direct consequence of the way that statins work, as they do not only suppress the production of cholesterol, they also suppress the production of other substances that are important for health. Also, since cholesterol is essential to the body in many ways, decreasing its availability may cause problems. For more information, see the article on statin side effects.
Alternatives to statins for lowering high cholesterol
Although statins are the most commonly prescribed drugs for lowering cholesterol, there are a number of other pharmaceutical treatments that may be tried, sometimes in conjunction with statins. These include Bile Acid Sequestrants, Nicotinic Acid and Ezetimibe. Other drugs may also be prescribed to try and increase levels of HDL cholesterol.
Further information on these alternative treatments to statins can be found in other articles.