Tuesday April 1 2014
Statins are usually used to reduce cholesterol levels in the blood
“How statins could boost your love life: Cholesterol lowering drugs ‘reduce erectile dysfunction’,” reports the Daily Mail.
The paper reports on a small but well-conducted analysis of existing data into statin use and symptoms of erectile dysfunction (inability to obtain or maintain an erection).
Statins are widely used to reduce cholesterol levels in an attempt to prevent cardiovascular diseases such as heart attacks.
The researchers’ analysis found that statins did improve scores on the International Inventory of Erectile Dysfunction – a well-validated “scorecard” for erectile dysfunction.
The researchers state that the increase seen was equivalent to about one-third of the improvement seen with drugs specifically designed to treat erectile dysfunction, such as the class of drugs known as phosphodiesterase 5 (the most famous of which is Viagra aka sildenafil).
It is unclear how statins may improve erectile dysfunction, but the researchers speculate that it may be due to decreased levels of LDL cholesterol and improved endothelial function – which includes the ability of blood vessels to dilate and constrict. This could then increase the flow of blood to the penis.
Although the methods used by the researchers were sound, the 11 randomised controlled trials included in the analysis only included a total 713 men.
Statins are unlikely to be prescribed for erectile dysfunction in men without cardiovascular risk factors.
Where did the story come from?
The study was carried out by researchers from Rutgers Robert Wood Johnson Medical School in the US.
No source of funding was reported, but the researchers state that they have no conflicts of interest.
The study was published in the peer-reviewed Journal of Sexual Medicine.
The results of the study were well reported in the Daily Mail.
What kind of research was this?
This was a systematic review and meta-analysis of studies assessing the effects of statin therapy on erectile dysfunction.
A systematic review is an overview of primary studies. Systematic reviews use explicit and reproducible methods to search for and assess studies for inclusion in the review. A meta-analysis is a mathematical synthesis of the results of the included studies.
This is an appropriate way of pooling and studying the body of available evidence on a specific topic.
What did the research involve?
The researchers studied databases of published literature to identify studies that had assessed the effects of statin therapy on erectile dysfunction. They excluded studies in animals, basic science or nutrition studies, reviews, editorials, case reports and studies which did not assess the effect of statin therapy on erectile dysfunction.
Once the studies had been identified, the researchers assessed study quality to see if there were any biases, and extracted data about the study characteristics and results.
The researchers extracted five-item International Inventory of Erectile Function (IIEF) scores. The five-item IIEF is a widely used, multi-dimensional self-report instrument for the evaluation of male sexual function. Possible scores range from 5 to 25. Lower scores represent poorer sexual function.
The researchers then performed a meta-analysis to combine the results of the included studies.
What were the basic results?
The researchers identified 11 randomised controlled trials (RCTs) and three observational studies.
The researchers initially performed a meta-analysis of the RCTs (which included 713 people).
The IIEF score increased significantly by 3.4 points with statins compared to control. The researchers state that this increase is about one-third of the improvement seen with phosphodiesterase 5 inhibitors (which include Viagra). These are a class of drugs designed to temporarily boost the flow of blood to the penis during sexual stimulation.
The three observational before and after studies did not show a significant difference in IIEF score before and after statin administration. However, when these were combined with the RCTs, statins were still associated with a significant 3.2 point improvement in IIEF score.
How did the researchers interpret the results?
The researchers conclude that “statins cause a clinically relevant improvement of erectile function as measured by the five-item version of the IIEF.”
This systematic review and meta-analysis found that statins improved scores on the International Inventory of Erectile Dysfunction. The researchers state that the increase seen was equivalent to about one-third of the improvement seen with phosphodiesterase 5 inhibitors (which include Viagra).
It is unclear how statins may improve erectile dysfunction but the researchers speculate that it may be due to decreased levels of LDL cholesterol and improved endothelial function – which includes the ability of blood vessels to dilate and constrict.
Although systematic reviews and meta-analyses are the appropriate way of pooling and studying the body of available evidence on a specific topic, it only included 11 RCTs featuring 713 people. As the researchers point out, the studies used different statins at different doses, had different follow-ups and were on different populations.
Statins are unlikely to be prescribed for erectile dysfunction in men without cardiovascular risk factors; at least in the near future.
If you are having problems with erectile dysfunction, and the lifestyle factors discussed above fail to help, then contact your GP for advice. The causes of erectile dysfunction can also be psychological as well as physical, so drug treatment may not be the best option for you.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.