Quality of life score is primarily affected by the mental rather than the physical component in patients with restless legs syndrome

Abstract

We read with interest the article by Nomura et al.1 concluding that the prevalence of restless legs syndrome (RLS) in the rural population is lower than that reported for Caucasian population.1 The study presents further evidence of disturbed quality of life (QoL) and poor sleep in patients with RLS. Interestingly, it was reported that in patients with primary RLS, there were no evidence of reduced physical related QoL parameters, although mental related ones were significantly affected. Our group has an interest in RLS of uremic etiology, investigating means of improving functional capacity and QoL in hemodialysis (HD) patients with the syndrome.2 From baseline data in a study underway assessing the effectiveness of exercise training in HD patients with RLS, we made similar observations regarding the QoL to those reported from Nomura et al.1 More specifically, our preliminary data are derived from 78 stable HD patients (58 male, 20 female, 53.94 ± 16.74 years), divided into two groups according to their RLS status using the International RLS (IRLS) study group criteria3: the RLS group (n= 30, 20 male, 53.0 ± 19.0 years) and the non-RLS group (n = 48, 38 male, 55.1 ± 13.2 years). We examined the impact of RLS in patients' with physical-related QoL and functional capacity. QoL was assessed by the SF-36 questionnaire, and functional capacity was evaluated by using the North Staffordshire Royal Infirmary test, whereas RLS severity was assessed by the International RLS study group rating scale.4 Even though Nomura's study deals with primary and our study with uremic RLS, we also observed the total QoL score and mental health component were both significantly compromised in the RLS group compared to the non-RLS group. In agreement with Nomura's study, our SF-36 physical health dimension and functional capacity score did not differ between the RLS and non-RLS groups. In addition, significant negative correlations (P < 0.05) were observed between the IRLS score on one hand and the SF-36 total score (r = −0.463), the SF-36 role physical scale (r = −0.519), the SF-36 general health (r = −401), and the SF-36 physical health dimension (r = −0.523) on the other. The differences in total QoL score when comparing RLS and non-RLS patients could be explained by the significantly diminished mental-related scales score that both our and Nomura's patients experienced, compared with their free RLS counterparts. Even though primary and secondary RLS do not seem to share the same etiology, both studies conclude that RLS did not seem to have any detrimental effect on the physical and functional capacity of the patients. These findings seem logical because limp movements and in general various types of physical activities that temporarily ameliorate RLS symptoms result in more physical activity; however, because this type of activity is a necessity rather a personal choice, the situation can in turn make RLS patients mentally distressed. Nomura et al. have reported a low-RLS prevalence in a rural population (1.8%) compared to general adult population of Japan (4.01%)5, in agreement with another study by Hadjigeorgiou et al,6 contacted in a similar mixture of population in central Greece that reported a low-prevalence of RLS (3.9%) compared to other Caucasian populations. The fact that high levels of physical activity are usually observed in rural population because the nature of their occupations could also help toward preserving functionality. In conclusion, similar to primary RLS as shown by Nomura et al, uremic etiology RLS appears not to have any detrimental effect on physical QoL or functional capacity. It is important, however, to note that in rural RLS patients, the increased everyday activity could mask any potential effect of the syndrome to the physical related QoL, and therefore, further research is needed engaging other types of populations. Christoforos D. Giannaki BSc, MSc [email protected]* , Giorgos K. Sakkas PhD* , Georgios M. Hadjigeorgiou MD, PhD §, Vassilios Liakopoulos MD, PhD* §, Georgios Anifandis PhD*, Christina Karatzaferi PhD ¶, Yiannis Koutedakis PhD ¶, Ioannis Stefanidis MD, PhD* §, * Department of Nephrology, School of Medicine, University of Thessaly, Larissa, Greece, Institute for Human Performance and Rehabilitation, CE.RE.TE.TH, Trikala, Greece, Department of Neurology, School of Medicine, University of Thessaly, Larissa, Greece, § Institute of Biomedical Research and Technology, CE.RE.TE.TH, Larissa, Greece, ¶ Department of Sport Science, University of Thessaly, Trikala, Greece.