Restless Leg Syndrome and Objectively-Measured Atherosclerosis in the Canadian Longitudinal Study on Aging

Restless legs syndrome, periodic limb movements of sleep, and subclinical cardiovascular disease

Restless legs syndrome (RLS) and periodic limb movements of sleep (PLMS) have been variably implicated in risk for cardiovascular disease (CVD), but there is lack of consensus on these relationships. We sought to assess subclinical CVD measures and RLS/PLMS in a large cohort to further evaluate these associations. The Emory Center for Health Discovery and Well Being cohort is composed of employed adults, with subclinical CVD measures including endothelial function (flow-mediated vasodilation), microvascular function (reactive hyperemia index, RHI), arterial stiffness (pulse wave velocity and augmentation index), and carotid intima-media thickness (cIMT). Participants were grouped based on presence (N = 50) or absence (N = 376) of RLS and subclinical CVD measures compared between groups. A subset of participants (n = 40) underwent ambulatory monitoring for PLMS and obstructive sleep apnea. PLMS association with subclinical CVD measures was assessed. RLS status was significantly associated with flow-mediated dilation in univariate analyses but not after controlling for potential confounders; RLS was not associated with other subclinical CVD measures. PLMS were significantly correlated with the RHI, augmentation index, and cIMT in univariate analyses; only the association between PLMS and cIMT remained significant (p = 0.04) after controlling for RLS status, age, apnea-hypopnea index, hyperlipidemia, and hypertension. The observed association between higher PLMS and greater cIMT suggests that PLMS may be a marker of subclinical CVD. Further work is needed to determine the relationship between PLMS and CVD risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-023-00497-7.

Sleep disorders and mortality: A prospective study in the Canadian longitudinal study on aging

BACKGROUND AND OBJECTIVES

Sleep disorders are commonly linked to various health conditions, although it remains unclear to what degree they are linked with overall mortality. We compared mortality in different self-reported sleep disorders in a large population-based prospective study.

METHODS

In this case-control study within the CLSA cohort, participants completed a questionnaire at baseline (2011-2015) measuring overall sleep satisfaction, daily sleep duration, sleep-onset and sleep-maintenance insomnia, daytime somnolence, REM sleep behavior disorder (RBD), restless leg syndrome (RLS), and obstructive sleep apnea (OSA). The vital status of participants was assessed in July 2019. Baseline sleep problems of participants who died (cases) were compared to those who survived (controls). For each case, five age/sex-matched controls were selected. Binary logistic regression was used to estimate the association between sleep symptoms and mortality, adjusting for age, sex, marital status, province, education, alcohol consumption, smoking, caffeine, and body mass index. In a complementary model, anxiety and depression were also added.

RESULTS

Among 30,097 participants at baseline, 974 deaths were reported in 2019 (60.7 % male, age = 72.3 ± 9.4 years). In the initial analysis, mortality cases reported more baseline sleep-maintenance insomnia (12.1 % vs. 8.0 %, Adjusted OR[95%CI] = 1.62[1.15,2.29]), daytime somnolence (2.4 % vs. 1.1 %, AOR = 2.70[1.34,5.44]), and higher possible RLS (16.4 % vs. 12.4 %, AOR = 1.50[1.09,2.05]). They were also more likely to screen positive for possible OSA (33.8 % vs. 24.2 %, AOR = 1.32[1.07,1.64]); however, this effect was not related to core apnea symptoms. Sleep durations exceeding 10 h/day were also associated with increased mortality (3.4 % vs. 1.9 %, AOR = 1.83[1.04,3.24]). Other sleep symptoms/disorders, such as sleep-onset insomnia (7.3 % vs. 4.3 %, AOR = 1.54 [1.00,2.37]), possible RBD (5.3 % vs. 5.1 %, AOR = 1.02[0.62,1.69]), and overall sleep dissatisfaction (26.5 % vs. 22.6 %, AOR = 1.14[0.93,1.41]) were not different among these groups. After adding anxiety and depression to the adjustment model, all differences attenuated to become statistically non-significant, except for daytime somnolence disorder. When stratified by sex, the association between sleep disorders and mortality was only observed in women, with men showing no association.

DISCUSSION

We confirm a relationship between numerous sleep disorders and mortality. This effect is most evident in women, and appears to be strongly related to co-existing anxiety and depression.

Individualized References of Carotid Stiffening Quantified With Ultrafast Ultrasound Imaging: Model Construction and Preliminary Validation

To establish and preliminarily validate an individualized reference of carotid stiffness quantified by ultrafast pulse wave velocity (ufPWV), our study included 225 healthy individuals in the modeling cohort and 628 individuals in the validation cohort. All participants underwent assessment of carotid intima-media thickness (cIMT), pulse wave velocity-beginning of systole and pulse wave velocity-end of systole (PWV-ES). A threshold equation of estimated PWV-ES was obtained by multiple linear regression analysis in the modeling cohort as follows: estimated PWV-ES (m/s) = 0.080 × age (y) + 0.767 × low-density lipoprotein (mmol/L) + 0.040 × systolic blood pressure (mm Hg) + 0.372 × sex (male = 1, female = 0) - 2.803. With this equation, the validation cohort was divided into the low PWV-ES (actual PWV-ES ≤ estimated PWV-ES) and high PWV-ES (actual PWV-ES > estimated PWV-ES) groups. A clear boundary was found to be present between the low PWV-ES and high PWV-ES groups in the validation cohort. Participants with increasing PWV-ES increased with age gradually. We further subdivided participants into cIMT subgroups using a cutoff thickness of 0.050 cm. Diagnostic performance analysis revealed that the sensitivity and specificity of the threshold equation were 78.9% and 73.9%, respectively. We established and validated a novel individualized reference equation for estimated PWV-ES, which can likely expand the application of prospective ufPWV assessment.

Cardiac Involvement in Movement Disorders

Background

Several conditions represented mainly by movement disorders are associated with cardiac disease, which can be overlooked in clinical practice in the context of a prominent primary neurological disorder.

Objectives

To review neurological conditions that combine movement disorders and primary cardiac involvement.

Methods

A comprehensive and structured literature search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria was conducted to identify disorders combining movement disorders and cardiac disease.

Results

Some movement disorders are commonly or prominently associated with cardiac disease. Neurological and cardiac symptoms may share underlying physiopathological mechanisms in diseases, such as Friedreich's ataxia and Wilson's disease, and in certain metabolic disorders, including Refsum disease, Gaucher disease, a congenital disorder of glycosylation, or cerebrotendinous xanthomatosis. In certain conditions, such as Sydenham's chorea or dilated cardiomyopathy with ataxia syndrome (ATX-DNAJC19), heart involvement can present early in the course of disease, whereas in others such as Friedreich's ataxia or Refsum disease, cardiac symptoms tend to present in later stages. In another 68 acquired or inherited conditions, cardiac involvement or movement disorders are seldom reported.

Conclusions

As cardiac disease is part of the phenotypic spectrum of several movement disorders, heart involvement should be carefully investigated and increased awareness of this association encouraged as it may represent a leading cause of morbidity and mortality.