Socio-economic risk factors for incident restless legs syndrome in the general population

Few and controversial data exist about the relationship between socio-economic status and restless legs syndrome, and prospective analyses are lacking. We aimed to explore the associations between socio-economic factors and incident restless legs syndrome in the general population. Two prospective population-based cohort studies were conducted: the Dortmund Health Study with a mean follow-up of 2.2 years; and the Study of Health in Pomerania with a mean follow-up of 5.2 years. The studies included 1312 subjects and 4308 subjects, respectively. Restless legs syndrome was assessed twice according to the standard minimal criteria. The modified Winkler Index of social class, education, job status, partnership and income were assessed by interviews at baseline. The risk of restless legs syndrome associated with each socio-economic factor was estimated by multivariable logistic regression adjusted for behavioural factors and co-morbidities. Female gender, being retired and unemployment were independent risk factors of incident restless legs syndrome in both studies. Low level of education and income were independently associated with incident restless legs syndrome only in the Dortmund Health Study, but not in the other study. Migrational background and shiftwork were further independent risk factors of restless legs syndrome that were only assessed in the Dortmund Health Study. People with less favourable socio-economic situation are at an increased risk of developing restless legs syndrome. Behavioural variables and co-morbidities did not explain this association, thus further studies are required to reveal the mechanism behind the proposed relationship.