How do statins affect cholesterol and triglyceride levels?
Combined results from 19 trials involving more than 50,000 people (23% were women) show that statins lower LDL (bad) cholesterol by 20% to 40%.8 This benefit was seen in women and the elderly, and across a wide range of LDL cholesterol levels. Some statins are better than others for lowering LDL cholesterol (See Which statin is best for lowering cholesterol? below) and the same statin is generally more effective at higher doses. Statins also lower total cholesterol by about 25% and triglycerides (another type of lipid that is associated with heart disease) by 15%.9
Do statins prevent heart attacks or dying from heart disease in women with heart disease?
Yes. Studies show that statins lower the risk of dying from heart disease by 26%, and the risk of having a heart attack by 29% in women with heart disease even if their LDL cholesterol levels are not that high.10 In addition, women with heart disease treated with statins are 20% less likely to experience heart problems (including the need for a for angioplasty or bypass surgery) than women who do not take statins.11
Do statins prevent heart attacks and death in women who do not have heart disease?
Studies have shown that statins prevent heart attacks and reduce the risk of dying from heart disease in men with high cholesterol who do not have heart disease. However, when the results of 6 large studies including more than 11,000 women were analyzed by gender, this benefit was not proven in women.10 This didn't seem to make sense because statins lower cholesterol just as effectively in men and women, and there is no evidence that they work differently in men and women.12, 13 The researchers believe that there were simply too few women and the studies were too short to show the full benefits of statins in women. Women have a lower risk of heart disease than men at any age and they live longer, so you have to study a lot more women for a much longer time to see whether statins have a statistically significant effect on heart attack and death rates. It is estimated that almost twice as many women than men without heart disease have to be treated with statins to prevent a single heart problem including heart attack (140 women compared with 77 men).
Some experts believe that one of the six studies, the ALLHAT study, was not as thorough as the other five. When the ALLHAT study was left out of the pooled analysis, statins were shown to lower the risk of dying or having a heart attack in women who did not have heart disease.