Prevalence of restless legs syndrome among adults in Iceland and Sweden: Lung function, comorbidity, ferritin, biomarkers and quality of life

• Published in: Sleep Medicine
• Main Authors: Benediktsdottir, Bryndis, Janson, Christer, Lindberg, Eva, Arnardóttir, Erna Sif, Olafsson, Isleifur, Cook, Elizabeth, Thorarinsdottir, Elin Helga, Gislason, Thorarinn
• Other Authors: Faculty of Medicine, University of Iceland, Iceland.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsiver Sciencs 2011
• Subjects: Adult; Aged; Biological Markers; C-Reactive Protein; Comorbidity; Female; Ferritins; Humans; Hypertension; Iceland; Inflammation; Interleukin-6; Lung Diseases; Male; Metabolic Syndrome X; Middle Aged; Prevalence; Quality of Life; Restless Legs Syndrome; Smoking; Spirometry; Sweden; Reykjavík
• Online Access: http://hdl.handle.net/2336/125513; https://doi.org/10.1016/j.sleep.2010.08.006

To access publisher full text version of this article. Please click on the hyperlink in Additional Links field OBJECTIVE: This study investigates the prevalence and the association between restless legs syndrome (RLS) and a large variety of health variables in two well-characterized random samples from the general population in Reykjavik, Iceland, and Uppsala, Sweden. METHODS: Using the national registries of inhabitants, a random sample from adults aged 40 and over living in Reykjavík, Iceland (n=939), and Uppsala, Sweden (n=998), were invited to participate in a study on the prevalence of COPD (response rate 81.1% and 62.2%). In addition, the participants were asked to answer the following questionnaires: International RLS Rating Scale, Short Form-12, the Epworth Sleepiness Scale, and questions about sleep, gastroeosophageal reflux, diabetes and hypertension, as well as pharmacological treatment. Interleukin-6 (IL-6), C-reactive protein (CRP) and ferritin were measured in serum. RESULTS: RLS was more commonly reported in Reykjavik (18.3%) than in Uppsala (11.5%). Icelandic women reported RLS almost twice as often as Swedish women (24.4 vs. 13.9% p=0.001), but there was no difference in prevalence of RLS between Icelandic and Swedish men. RLS was strongly associated with sleep disturbances and excessive daytime sleepiness. Subjects with RLS were more likely to be ex- and current smokers than subjects without RLS (p<0.001). Respiratory symptoms and airway obstruction were more prevalent among those reporting RLS and they also estimated their physical quality of life lower than those without RLS (p<0.001). RLS was not associated with symptoms of the metabolic syndrome like hypertension, obesity, markers of systemic inflammation (IL-6 and CRP) or cardiovascular diseases. Ferritin levels were significantly lower in RLS participants (p=0.0002), but not (p=0.07) after adjustment for center, age, sex and smoking history. CONCLUSION: Restless legs syndrome was twice as common among Icelandic women compared to ...