Older men with restless leg syndrome (RLS) are more likely to have erectile dysfunction (ED) than men without RLS—and dopamine may be the common denominator, according to a study.
“The mechanisms underlying the association between RLS and erectile dysfunction could be caused by hypofunctioning of dopamine in the central nervous system, which is associated with both conditions,” lead author Xiang Gao, PhD, an associate epidemiologist at Brigham and Women’s Hospital in Boston, explained in a statement announcing study results. Dr. Gao also is an instructor at Harvard Medical School and a research scientist at the Harvard School of Public Health, also in Boston. Study findings appear in Sleep (2010;33:75-79).
Dr. Gao and colleagues collected data from 23,119 men participating in the ongoing Health Professionals Follow-up Study. The men were aged 56 to 91 years (mean 69 years). In 2002, study subjects were asked about the presence and severity of RLS, which was defined as unpleasant leg sensations combined with restlessness and an urge to move, with the symptoms appearing only at rest and improving with movement, worsening in the evening or at night compared with morning, and occurring at least five times per month.
Of the 23,119 men, 944 (4%) had RLS, and 9,433 (41%) had ED. ED was reported by 53% of the men with RLS and by 40% of those without.
After adjusting for age, smoking status, BMI, antidepressant use, and other covariates, Dr. Gao’s team found that ED was 16% more likely to be present in men experiencing RLS symptoms five to 14 times per month, and 78% more likely in men experiencing RLS symptoms 15 or more times per month.
“Men with RLS had a higher likelihood of concurrent ED, and the magnitude of the observed association was increased with a higher frequency of RLS symptoms,” the investigators concluded. “These results suggest that ED and RLS share common determinants.”