A time sequence analysis of the relationship between cardiovascular risk factors, vascular diseases and restless legs syndrome in the general population

Previous cross-sectional studies regarding the association of restless legs syndrome (RLS) with cardiovascular morbidity are controversial. Our aim was to evaluate prospectively the relationship of cardiovascular risk factors and vascular diseases with incident RLS in the general population. The results are from two prospective population-based cohort studies: the Dortmund Health Study (n = 1312, median follow-up of 2.1 years) and the Study of Health in Pomerania (n = 4308, median follow-up of 5.0 years). RLS status was assessed twice according to the minimal criteria. Diabetes, hypertension, myocardial infarction and stroke, as well as currently taken medications, were assessed as self-reports. Body mass index and serum total cholesterol were also measured. The independent risks associated with each outcome were estimated by multivariable logistic regression models adjusted for comorbidities and behavioural factors. Obesity was an independent risk factor of incident RLS in the Dortmund Health Study, and higher body mass index was an independent risk factor in both studies. Diabetes, hypertension and hypercholesterolaemia were independent predictors of incident RLS in the Study of Health in Pomerania. The vascular comorbidity index, defined by the number of concurrent cardiovascular risk factors and vascular diseases, showed a positive association with incident RLS in both studies. RLS at baseline was not a significant predictor of any subsequent cardiovascular risk factors and/or vascular diseases in any of the studies. Cardiovascular risk factors and diseases predict the subsequent development of RLS in the general population. The presence of RLS is not a significant risk factor of cardiovascular morbidity.