Subclinical target organ damage in patients with restless legs syndrome. a preliminary observational study

Objective: Restless legs syndrome (RLLS) is a frequent and often underdiagnosed type of insomnia. Since other types of insomnia present a strict association with cardiovascular disease, our study aimed to evaluate the possible association of RLLS with some early markers of cardiovascular organ damage. Design and method: Patients with other types of insomnia and those with central nervous system diseases were excluded. Twenty-eight patients (mean age: 63,1±13,9 years; 28.6% males) participated in the study. Fourteen subjects with diagnosis of RLLS according to International diagnostic criteria (Allen RP et al. 2014 Sleep Medicine) (disease mean duration 9.6±9.2 years; International Restless Legs Scale score 22.9±5.2) were matched for sex, age and major cardiovascular risk factors with 14 controls. In both groups, peripheral Blood Pressure (pBP), central Blood Pressure (cBP) and Pulse Wave Velocity (PWV) were assessed by the SphygmoCorXCEL. Carotid Intima-Media Thickness (cIMT) and the carotid Distensibility Coefficient (cCD) were assessed by ultrasound connected with an image acquisition and analysis system (CardiovascularSuite). Results: We did not find any significant difference between the two groups in the indices of subclinical vascular damage. In the RLS group, blood pressure measurements significantly correlated with all the markers of subclinical vascular damage, particularly pSBP was associated with PWV (r = 0.53, p = 0.009), Pulse Pressure correlated with cIMT (r = 0.58, p = 0.01) and cDBP was inversely related to cDC (r = -0.53; p = 0.03). Conclusions: Our data did not show significant differences in markers of early vascular damage between patients with RLS and matched controls. As expected, the markers of vascular damage were associated with BP. The present is only a pilot study; further studies with a larger sample size are required to confirm our findings.