Statins may reduce some cancer risks but contribute to fatigue
Statins are one of the most commonly prescribed medications in the United States. Yet, some in the medical community believe that more patients should be on this class of drugs while others think it is one of the most overprescribed medications. Suffice to say, this is one of the most polarizing topics in medicine — probably rightfully so.
The debate is over primary prevention with statins. Primary prevention is treating people with high cholesterol and/or inflammation who may be at risk for a cardiovascular event, such as a stroke or heart attack. Fortunately, most physicians would agree that statins have their place in secondary prevention — treating patients who have had a stroke or heart attack already or have coronary artery disease.
We are going to look at benefits and risks for the patient population that could take statins for primary prevention. On one side, we have the statin as Rocky Balboa, coming out to fight off cancer risk, both overall and esophageal, as well as improving quality of life and eye disease (glaucoma). On the other, we have the statin as Evel Knievel, demonstrating that being reckless doesn’t provide longevity, promotes fatigue and increases eye disease (cataracts). Let’s look at some of the evidence.
Effect on cancer
A recent study published in The New England Journal of Medicine involved 300,000 Danish participants and investigated 13 cancers. It showed that statin users may have a 15 percent decreased risk of death from cancer (N Engl J Med 2012;367:1792-1802). This is exciting news.
However, there were major limitations with the study. First, the researchers did not control for smoking, which we know is a large contributor to cancer. Secondly, it was unknown which of the statin-using population might have received conventional cancer treatments, such as radiation and chemotherapy. Thirdly, the dose of statins did not correlate to risk reduction. In fact, those who took 1 percent to 75 percent of prescribed statin levels showed more benefit in terms of cancer-mortality risk than those who took more. There needs to be a better-designed trial that is prospective (forward looking) to determine whether there really is an effect. I would say that Rocky Balboa came out of this fight pretty banged up.
Another study showed that statins may play a role in reducing the risk of esophageal cancer. This is important, since esophageal cancer, especially adenocarcinoma that develops from Barrett’s esophagus, is on the rise. The results showed a 30 percent risk reduction in this type of cancer. The authors of the study surmise that statins may have a protective effect. This was meta-analysis of 13 observational studies. The study abstract was presented at the American College of Gastroenterology 2012 Annual Scientific Meeting (Abstract 1 May 22, 2012).
Although there is an association, these results need to be confirmed with randomized controlled trials. Remember, aspirin has about the same 30 percent reduction in colorectal cancer, yet is not recommended solely for this use because of side effects.
Eye diseases: mixed results
In two common eye diseases, glaucoma and cataracts, statins have vastly different results. In one new study, statins were shown to decrease the risk of glaucoma by 5 percent over one year and 9 percent over two years (Ophthalmology 2012;119(10):2074-2081). It is encouraging that the longer the duration of statin use, the greater the positive effect on preventing glaucoma.
Statins also help to slow glaucoma progression in patients suspected of having early-stage disease at about the same rate. This was a retrospective study (backward-looking) analyzing statin use with patients at risk for open-angle glaucoma. There is a need for prospective (forward-looking) studies. With cataracts, it is a completely different story. Statins increase the risk of cataracts by over 50 percent, as shown in the Waterloo Eye Study (Optom Vis Sci 2012;89:1165-1171). Statins exacerbate the risk of cataracts in an already high-risk group: diabetes patients. For more details on this topic, see my Oct. 18 article, “Taking cataracts seriously to maintain good health.”
Quality of life and longevity: a mixed bag again
In a meta-analysis involving 11 randomized controlled trials, considered the gold standard of studies, statins did not reduce the risk of all-cause mortality in moderate to high-risk primary prevention participants (Arch Intern Med 2010;170(12):1024-31). This study analysis involved over 65,000 participants with high cholesterol and at significant risk for heart disease.
However, in this same study in Archives of Internal Medicine, participants at high risk of coronary heart disease saw a substantial improvement in their quality of life with statins. In other words, the risk of a nonfatal heart attack was reduced by more than half and nonfatal strokes by almost half, avoiding the potentially disabling effects of these cardiovascular events.
Some of my patients who are on statins ask if statins can cause fatigue. The answer is “maybe,” but now there is a randomized controlled trial that reinforces the idea that statins increase the possibility of fatigue (Arch Intern Med 2012;172(15):1180-1182).
Women, especially, complained of lower energy levels, both overall and on exertion, when they were blindly assigned to a statin-taking group. The trial was composed of three groups: two that took statins, simvastatin 20 mg and pravastatin 40 mg; and a placebo group. The participants were at least 20 years old and had LDL (bad) cholesterol of 115 to 190 mg/dl, with less than 100 mg/dl considered ideal.
In conclusion, some individuals who are at high risk for cardiovascular disease may need a statin, but with the evidence presented it is more likely that statins are overprescribed in primary prevention. As www.update.com points out, evidence of the best results points to lifestyle modification, with or without statins, and all patients with elevated LDL (bad) cholesterol should make changes that include a nutrient-dense diet and exercise.
Dr. Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, go to the website www.medicalcompassmd.com and/or consult your personal physician.