In general, sleep disorders have been consistently linked with higher mortality.
A recent study found that restless legs syndrome (RLS) could lead to an approximately 40 percent higher risk of early death.
Published in the journal Neurology, this study collected information using the Health Professionals Follow-Up Study. The researchers took information from over 18,000 men that were free of diabetes, arthritis, and renal failure. In 2002, RLS was assessed through a questionnaire. The study had follow-up data for the next eight years, through 2010. The researchers documented approximately 2,700 deaths. After adjusting for age, other chronic conditions, body mass index, and other sleep-related disorders, the researchers found a 39 percent higher risk of early mortality.
According to USA Today, this is a marked departure from earlier studies, which concluded that having RLS did not raise the risk of earlier death. An author of one of the earlier studies cautions that these results may not be applicable to the general population as they focus on a narrow subset. The researchers in this study noted that early death in those with restless legs syndrome was most commonly related to respiratory, endocrine, metabolic, or immunologic disorders, which could indicate other underlying conditions that are the true source of early mortality.
The Johns Hopkins University Center for Restless Legs Syndrome describes RLS as a “neurological condition associated with abnormal sensations in the legs.” The syndrome, also known as Willis-Ekbom Disease, has four key signs: uncomfortable sensation with a clear need to move the legs, exacerbation of symptoms at night, reduction of symptoms with rest, and reduction of symptoms with movement.
The Journal of Parkinsonism and Restless Legs Syndrome has published numerous articles on the condition. One of the articles identifies RLS as a sleep-related disorder that may also be related to a dysfunction in the way the body produces and processes dopamine. While no structural changes in the brain can confirm that, the efficacy of dopaminergic agents in addressing RLS suggests a link. There is also a likely genetic or hereditary source, with 65 percent of patients presenting with the condition having knowledge of an immediate relative that also has RLS.
In general, sleep disorders have been consistently linked with higher mortality. One study, which utilized twins with different sleep patterns, found a higher risk of natural death related to consistent short sleep (fewer than seven hours) and consistent long sleep (greater than eight hours). This trend was confirmed for both men and women. While short and long sleep may be related to other conditions or lifestyle factors, sleep is an important indicator of mortality risk.