Restless legs syndrome (RLS) is a not uncommon pervasive and unpleasant disorder characterized by a burning, tickling or itching sensation in the feet associated with an irresistible urge to move. The disorder, of which I used to see many cases in my patients on hemodialysis, is difficult to treat and can become so severe that it results in sleep deprivation and severe distress.
Although its aetiology remains obscure, it has been linked to nutritional deficiencies (most commonly iron) but also to hypofunction of the dopaminergic system in the brain (as has obesity).
In this month’s issue of Neurology, Xiang Gao and colleagues from Harvard Medical School, Boston, MA, USA, report a higher incidence of RLS in both the 65,000 women in the Nurses’ Health Study as well as the 23,000 Men in the Health Professionals Follow-up Study. Participants were considered to have RLS if they met four RLS diagnostic criteria recommended by the International RLS Study Group and had restless legs > or =5 times/month.
RLS was present in 6.4% of women and 4.1% of men. Despite multivariate adjustment for age, smoking, use of antidepressant, phobic anxiety score, and other covariates, the odds for RLS were 1.42 for participants with BMI >30 vs <23 and 1.60 for the highest vs lowest waist circumference quintiles. The association was even stronger for individuals with greater BMI in early adulthood (age 18-21 years).
The authors conclude that both overall and abdominal adiposity are associated with greater likelihood of RLS.
This may not be surprising, because many of the conditions associated with RLS including nutritional deficiencies, sleep apnea, ADHD and others, are likewise more common in obese individuals.
Clinicians should specifically explore the presence of symptoms of RLS in patients present with obesity and weight gain.
AMS
Edmonton, Alberta
p.s for more information on RLS go to the RLS Foundation Website - click here for a patient information sheet in English or French
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