Prevalence and associated factors of restless legs in a 57-year-old urban population in northern Finland

Objective - We examined the prevalence and associated factors of restless legs syndrome (RLS) in a 57-year-old unselected urban population in northern Finland. Methods - A health survey was conducted in 2002 that targeted persons born in 1945 and residing in the city of Oulu on 31 December, 2001. Their history of RLS, coronary heart disease (CHD), daytime sleepiness, depressive symptoms and snoring was assessed by means of questionnaires. Results - Altogether 995 of 1332 eligible subjects (74%) participated (556 women, 439 men). The overall prevalence of RLS >= 1 per week was 20% in women and 15% in men. In the fitted multiple logistic regression model, RLS was found to be associated with female gender (OR 1.64, 95% CI 0.98-2.72), CHD (OR 2.92, 95% CI 1.18-7.23), daytime sleepiness (OR 2.12, 95% CI 1.32-3.41), moderately elevated (31-45) or high (46-65) Zung sum scores (OR 1.95, 95% CI 1.09-3.48 and OR 3.67, 95% CI 1.71-7.90, respectively), antidepressant medication (OR 2.10, 95% CI 1.06-4.19) and arthropathy (OR 1.69, 95% CI 1.04-2.72). Insufficient evidence was found of an association between RLS and type 2 diabetes or impaired glucose regulation. Conclusions - Restless legs syndrome is fairly common in subjects aged 57 years. A particularly strong positive association was observed between RLS and depressive symptoms and CHD.