Restless legs syndrome: a community-based study of prevalence, severity, and risk factors.
OBJECTIVE
To assess the prevalence and severity of restless legs syndrome (RLS) in the general community and to investigate its potential relationship with iron metabolism and other potential risk factors.


METHODS
This was a cross-sectional study of a sex- and age-stratified random sample of the general population (50 to 89 years; n = 701). The diagnosis of RLS was established by face-to-face interviews; severity was graded on the RLS severity scale. Each subject underwent a thorough clinical examination and extensive laboratory testing.


RESULTS
The prevalence of RLS was 10.6% (14.2% in women, 6.6% in men); 33.8% of all patients with RLS had mild, 44.6% had moderate, and 21.6% had severe disease expression. None had been previously diagnosed or was on dopaminergic therapy. Free serum iron, transferrin, and ferritin concentrations were similar in subjects with and without RLS. However, soluble transferrin receptor (sTR) concentrations were different in subjects with and without RLS (1.48 vs 1.34 mg/L; p < 0.001). Female sex and high sTR independently predicted the risk of RLS.


CONCLUSIONS
This large survey confirms the high prevalence, female preponderance, and underrecognition of restless legs syndrome in the general community. Although two-thirds of patients had moderate to severe disease, none was on current dopaminergic therapy.
Högl
B
B
Department of Neurology, Innsbruck Medical University, Anichstr. 35, 6020 Innsbruck, Austria.
Kiechl
S
S
Willeit
J
J
Saletu
M
M
Frauscher
B
B
Seppi
K
K
Müller
J
J
Rungger
G
G
Gasperi
A
A
Wenning
G
G
Poewe
W
W
D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004298:Dopamine / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D005293:Ferritins / Q000097:blood; D006306:Health Surveys; D006801:Humans; D007501:Iron / Q000097:blood; D019189:Iron Metabolism Disorders / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011990:Receptors, Transferrin / Q000097:blood; D012148:Restless Legs Syndrome / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D012307:Risk Factors; D012737:Sex Factors; D014168:Transferrin / Q000378:metabolism
D011990:Receptors, Transferrin; D014168:Transferrin; D005293:Ferritins; D007501:Iron; D004298:Dopamine