HealthDay News — Men with restless legs syndrome (RLS) have a significantly increased risk of mortality, independent of other known risk factors, according to a study published in Neurology.
“The results of this study indicate that men with RLS had a higher overall mortality, which highlights the clinical importance of RLS, a common but underrecognized disorder,” report Yanping Li, PhD, from Brigham and Women’s Hospital in Boston, and colleagues.
RLS is a neurological disorder characterized by a persistent need to move one’s legs, particularly at night. It affects an estimated 5-10% of adults. Previous studies that have examined its relationship with mortality have yielded mixed results.
In the study, data was used from a prospective cohort of 18,425 US men free of diabetes, arthritis, and renal failure participating in the Health Professionals Follow-up Study, which is an ongoing, prospective investigation of male health professionals ages 40 to 75 at baseline. RLS was assessed in 2002 using a set of standardized questions and it was found that 3.7% of the sampled population met criteria for the condition. The subjects were then followed through 2010.
During the eight years of follow-up, the researchers identified 2,765 deaths, or about 15% of the examined population. RLS was associated with a 39% increased risk of mortality. After adjustment for body mass index, lifestyle factors, chronic conditions, sleep duration, and other sleep-related disorders, the correlation was slightly attenuated, but remained significant at a 30% increased risk of morality.
When excluding participants who had major chronic health conditions, such as cancer, Parkinson’s disease, high blood pressure, cardiovascular disease, and diabetes, the relationship was even stronger, as these men had an increased risk of mortality of 92%.
After researchers took specific causes of death into account, RLS appeared to be related to some conditions but not to others. Men suffering from respiratory disease had a 73% elevated risk of death. In addition, those with endocrine, nutritional, and immunity disorders or diseases of the blood and blood-forming organs were approximately five to six times more likely to die. No significant connection to RLS was found for deaths from cardiovascular causes or cancer.
The severity of the condition appeared to correlate with higher mortality rates. Men who reported symptoms of RLS five to 14 times per month had a 33% increased chance of mortality, whereas that figure jumped to 46% for men who reported symptoms 15 or more times per month.
In an effort to explain the significant relationship, the researchers noted that underlying neurodegenerative disorders manifesting as RLS might be the reason behind the correlation.
The study also listed several potential limitations of the research, such as their lack of information on medications used for RLS, the lack of objective measurements of iron deficiency, and the identity of their sample population, which consisted mostly of healthy white men.
The researchers were aware of the possibility of a causal connection, even if one cannot be confirmed by observational studies alone. “If our findings are confirmed by future studies,” they said, “increasing awareness of RLS, especially training for health professions, should be encouraged.