A review of dozens of studies on the use of statin medications shows that the commonly prescribed drugs pose no threat to short-term memory, and might even protect against dementia when taken for more than a year.
Researchers with Johns Hopkins, who conducted the systematic review, said the results should offer more clarity and reassurance to patients and to clinicians who prescribe the medications.
In February 2012, the Food and Drug Administration ordered drug labels to be changed to warn about memory problems with short-term statin use in some cases. However, in their extensive review, the Johns Hopkins researchers found that statins do not hamper short-term memory or cognition.
When the drugs are taken for more than a year, the risk of dementia is reduced by 29%, the researchers reported Oct. 1 on the website of the journal Mayo Clinic Proceedings.
All medications, including statins, may cause side effects, and many patients take multiple medicines that could theoretically interact with each other and cause cognitive problems, Kristopher Swiger, MD, a primary author of the study, said in the news release. However, our systematic review and meta-analysis of existing data found no connection between short-term statin use and memory loss or other types of cognitive dysfunction.
The researchers conducted two analyses involving a total of 41 different studies, which they narrowed down to 16 that had the most relevance. The first analysis looked at the impact of short-term statin use on cognitive function including memory, attention and problem-solving. For that analysis, they included studies that used a standard, objective measurement tool known as the Digit Symbol Substitution Test.
The other assessment focused on studies in which participants took statins for more than a year to determine whether there was any correlation with a subsequent diagnosis of Alzheimers disease or vascular dementia.
Our goal was to provide clarity on this issue based on the best available evidence, Raoul Manalac, MD, a co-primary author of the study, said in the news release. We looked at high-quality, randomized controlled trials and prospective studies that included more than 23,000 men and women with no prior history of cognitive problems. The participants in those studies were followed for up to 25 years.
Statins have been shown to reduce coronary artery disease and stroke among those at high risk and among those who have already been diagnosed with cardiovascular disease following a myocardial infarction or stroke. Statins also have been shown to reduce the amount of inflammation within blood vessels and prevent the risk of clotting.
Because of their effect on arteries to reduce or stabilize plaque, and prevent strokes, it makes sense that statins could be protective in the brain against dementia, said Seth Martin, MD, the studys senior author and a Pollin Cardiovascular Prevention Fellow with the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease.
Vascular dementia is caused by blockages in small blood vessels in the brain that prevent blood flow to certain areas. Medications such as statins that reduce plaque and inflammation in coronary arteries may also be having the same effect on blood vessels in the brain.