The impact of restless legs syndrome on physical functioning in a community-dwelling population of middle-aged and elderly people.

Objective: To investigate whether restless legs syndrome (RLS) is associated with impaired physical functioning using subjective and objective assessments.

Methods: From 2006-2013, 5,960 participants (mean age 67.2; 57.5% females) of the prospective population-based Rotterdam Study, aged 45 years and over, were cross-sectionally investigated for presence of restless legs syndrome using a questionnaire. Physical functioning was assessed subjectively with the Stanford Health Assessment Questionnaire (basic activities of daily living) and the Instrumental Activities of Daily living scale (instrumental activities of daily living). Additionally, physical functioning was assessed objectively by quantifying fine motor performance with the Purdue Pegboard Test and by quantifying gait with an electronic walkway.

Results: Restless legs syndrome was present in 13.7% of the participants. Persons with restless legs had more impairment in basic (difference in score 0.65, 95% CI 0.41;0.90) and instrumental activities of daily living (difference in score 0.28, 95% CI 0.09;0.48) than persons without restless legs. This association was strongest when symptoms were present two or more times a week (basic activities of daily living score difference 1.69, 95% CI 1.28;2.09). The association between restless legs syndrome and activities of daily living attenuated after adjusting for sleep quality or depressive symptoms. There was no association with the Purdue Pegboard Test score nor with gait.

Conclusions: Individuals with restless legs syndrome experienced significantly more impairment in activities of daily function than persons without restless legs. This seemed to be (partly) mediated by poor sleep quality and depressive symptoms. No association was found with objectively assessed physical functioning.