Absence of cardiovascular disease risk factors in restless legs syndrome

Prevalence and Determinants of Restless Legs Syndrome (Willis-Ekbom Disease) in an Older Greek Population

OBJECTIVES

The present study aimed to explore the descriptive and analytic epidemiology of restless legs syndrome (RLS) in the older Greek population, with a specific focus on lifestyle indicators.

METHODS

Baseline data from the randomly selected non-demented older participants of the population-based HELIAD cohort were analyzed. Multivariable binary logistic regression with RLS diagnosis as the dichotomous dependent outcome was performed. Demographic, socioeconomic, anthropometric, dietary, sleep-related and psychological parameters, physical activity, use of psychoactive substances and personal medical history were investigated for potential associations.

RESULTS

A total of 133 from the eligible sample of 1,838 participants were diagnosed with RLS. The mean age-sex standardized prevalence of RLS among the elderly was estimated at 6.1% (95%CI = 5.0-7.2), with a female (8.0%, 95%CI = 6.4-9.6) to male (3.7%, 95%CI = 2.4-5.1) ratio of 2.1. The prevalence of RLS peaked during the 8^th decade of life and diminished thereafter. The positive associations of RLS with female sex [OR = 2.06, 95%CI = (1.19-3.57)], anxiety levels [assessed by the 22-point HADS scale, OR = 1.08, 95%CI = (1.03-1.13)] and traumatic brain injury [OR = 2.22, 95%CI = (1.37-3.62)] were reproduced. Good sleep quality was related to 55% [95%CI~(24-83%)] lower odds of having RLS in comparison with both poor and moderate quality. Adherence to the Mediterranean dietary pattern [assessed by a 55-point scale, OR = 1.06, 95%CI = (1.01-1.11)], and low daily energy intake [low-moderate vs. low: OR = 0.45, 95%CI = (0.26-0.79)]; [moderate-high vs. low: OR = 0.69, 95%CI = (0.40-1.22)]; [high vs. low: OR = 0.31, 95%CI = (0.13-0.69)] were related to RLS for the first time.

CONCLUSIONS

More emphasis should be placed on the dietary-nutritional aspects of RLS.

[Restless legs syndrome]

Restless legs syndrome (RLS) is seen widely in clinical practice. RLS commonly occurs at night time and presents with unpleasant or uncomfortable sensations in the legs that causes an urge to move them. This article describes the epidemiology, risk factors and pathophysiology of RLS. There is a detailed description of clinical presentations, diagnostic criteria and also management of RLS.

Restless legs syndrome, periodic limb movements during sleep and cardiovascular risk

Multiple mechanisms may modulate an association between restless legs syndrome/Willis-Ekbom disease (RLS/WED) and cardiovascular disease (CVD), including chronic sleep deprivation, intermittent, periodic limb movements in sleep (PLMS)-related autonomic fluctuations and possible autonomic dysfunction intrinsically associated with RLS per se. The purpose of this paper is to review the existing RLS/WED literature focusing on the pathophysiologic evidence for possible associations between RLS/WED and PLMS with CVD and events (CVE). Specific intrinsic dysautonomic aspects of the disease, which may contribute to generating CVD, are separately discussed. The association between RLS/WED and both CV risk factors and CVD still remains elusive. Although several shared pathophysiological causes could explain these possible relationships, the emerging body of literature focusing on these disorders remains controversial. Not only longitudinal population-based studies and meta-analyses, but also more animal models and therapeutic interventions are needed in order to build a sufficiently robust body of evidence on this topic.

Silent Cerebral Small Vessel Disease in Restless Legs Syndrome

STUDY OBJECTIVES

Growing literature suggests that patients with restless legs syndrome (RLS) may be at increased risk for hypertension, heart disease, and stroke. Cerebral small vessel disease (SVD) is a known risk factor for clinical stroke. This study evaluated silent cerebral SVD by MRI in patients with RLS, in the absence of a history of previous clinical stroke or known stroke risk factors and taking into account disease duration.

METHODS

Fifty-three patients with RLS < 10 y were prospectively recruited along with 44 with RLS > 10 y and 74 normal controls. A magnetic resonance imaging study was obtained from all subjects and scans were analyzed for area and volume of SVD.

RESULTS

There was a significant increase in SVD area in the entire group of RLS patients compared to controls (P = 0.036); this was almost entirely driven by the group with RLS > 10 y. SVD area and volume were significantly increased in patients with RLS > 10 y with respect to both controls (P < 0.0001 and P < 0.0014, respectively) and RLS < 10 y (P < 0.00022 and P < 0.003, respectively). Age, duration of RLS, and the interaction of age and duration of RLS were independent predictors of SVD disease. Duration of RLS was an independent predictor of the burden of cerebral SVD (area P < 0.00012 and volume P < 0.0025), whereas sex and insomnia were not.

CONCLUSION

RLS duration should be taken into account when analyzing the association between RLS and cerebrovascular disease; our data support the hypothesis that a long-lasting RLS and its accompanying periodic limb movements in sleep are a risk factor for silent SVD and perhaps for the development of clinical stroke.

The association of Restless Legs Syndrome with hypertension and cardiovascular disease

Restless Legs Syndrome (RLS), is a sensory-motor neurological disorder that appears to be surprisingly common in the community. Periodic limb movements in sleep are typically encountered in more than 80% of RLS patients and comprise involuntary muscular jerks in the lower limbs, such as flexion of the knees or ankles.  Iron deficiency and dopaminergic neuronal dysfunction in the central nervous system are currently thought to be the likely pathophysiological culprits. There is evidence linking RLS to hypertension and cardiovascular disease. This short review will first present a synopsis of epidemiological, clinical and pathophysiological data concerning the syndrome, and then information on the possible links between RLS and cardiovascular disorders.

The relationship among restless legs syndrome (Willis-Ekbom Disease), hypertension, cardiovascular disease, and cerebrovascular disease

Untreated sleep disorders may contribute to secondary causes of uncontrolled hypertension, cardiovascular disease (CVD), and stroke. Restless legs syndrome, or Willis–Ekbom Disease (RLS/WED), is a common sensorimotor disorder with a circadian rhythmicity defined by an uncontrollable urge to move the legs that worsens during periods of inactivity or at rest in the evening, often resulting in sleep disruptions. Sleep disorders such as insomnia and obstructive sleep apnea (OSA) are established risk factors for increased risk of hypertension and vascular diseases. This literature review outlines the lessons learned from studies demonstrating insomnia and OSA as risk factors for hypertension and vascular diseases to support the epidemiologic and physiologic evidence suggesting a similar increase in hypertension and vascular disease risk due to RLS. Understanding the relationships between RLS and hypertension, CVD, and stroke has important implications for reducing the risks associated with these diseases.

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.

Elevated C-reactive protein is associated with severe periodic leg movements of sleep in patients with restless legs syndrome

BACKGROUND

Restless legs syndrome (RLS) is a common sleep disorder in which urges to move the legs are felt during rest, are felt at night, and are improved by leg movement. RLS has been implicated in the development of cardiovascular disease. Periodic leg movements (PLMs) may be a mediator of this relationship. We evaluated systemic inflammation and PLMs in RLS patients to further assess cardiovascular risk.

METHODS

137 RLS patients had PLM measurements taken while unmedicated for RLS. Banked plasma was assayed for high sensitivity C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha).

RESULTS

Mean (SD) PLM index was 19.3 (22.0). PLMs were unrelated to TNF-a and IL-6, but were modestly correlated with logCRP (r(129)=0.19, p=0.03). Those patients with at least 45PLMs/h had an odds ratio of 3.56 (95% CI 1.26-10.03, p=0.02, df=1) for having elevated CRP compared to those with fewer than 45PLMs/h. After adjustment for age, race, gender, diabetes, hypertension, hyperlipidemia, inflammatory disorders, CRP-lowering medications, and body mass index, the OR for those with ≥ 45PLMs/h was 8.60 (95% CI 1.23 to 60.17, p=0.03, df=10).

CONCLUSIONS

PLMs are associated with increased inflammation, such that those RLS patients with at least 45PLMs/h had more than triple the odds of elevated CRP than those with fewer PLMs. Further investigation into PLMs and inflammation is warranted.