Older men who have restless legs syndrome (RLS) seem to have a higher risk of getting erectile dysfunction (ED) than men who do not, according to recent US research.

RLS is a condition that is characterised by an irresistible urge to move around, particularly in the evening, due to uncomfortable sensations that may affect the legs, arms or torso. 

Xiang Gao of Harvard University in Boston said that, while the finding did not prove that there was a causal link between RLS and ED, it showed that the two conditions could share common causes.

He said that, since his study was the first to examine the apparent link between the two conditions, there was still much work to be done in follow-up studies.

The research team studied more than 23,000 male dentists, optometrists, veterinary surgeons and other health professionals, all of whom rated their erections on a five-point scale.

The 23,000 subjects were also asked if they had experienced any of the symptoms of RLS.

4% of the study subjects, who had an average age of 70 years, reported symptoms of RLS. And 53% of that group reported additional trouble maintaining erections.

In subjects who did not report symptoms of RLS, 40% reported symptoms of ED.

Researchers found that the likelihood people would have ED varied with the severity of the RLS symptoms they reported.

Factors such as age, ethnicity, obesity, and tobacco use did not have any statistical effect on the results.

Thomas Pollmacher, director of mental health at Ingolstadt Hospital in Germany, said that, because the researchers did not ask subjects if doctors had diagnosed their RLS, the study provided a very rough assessment of the disease.

Gao said that some of the men who reported restless legs syndrome were probably wrongly self-diagnosing.

However, he also said that his team had observed that both conditions seemed to involve dopamine, an important neurotransmitter.