Perceived severity of restless legs syndrome across the female life cycle

Sleep disturbance in rodent models and its sex-specific implications

Sleep disturbances, encompassing altered sleep physiology or disorders like insomnia and sleep apnea, profoundly impact physiological functions and elevate disease risk. Despite extensive research, the underlying mechanisms and sex-specific differences in sleep disorders remain elusive. While polysomnography serves as a cornerstone for human sleep studies, animal models provide invaluable insights into sleep mechanisms. However, the availability of animal models of sleep disorders is limited, with each model often representing a specific sleep issue or mechanism. Therefore, selecting appropriate animal models for sleep research is critical. Given the significant sex differences in sleep patterns and disorders, incorporating both male and female subjects in studies is essential for uncovering sex-specific mechanisms with clinical relevance. This review provides a comprehensive overview of various rodent models of sleep disturbance, including sleep deprivation, sleep fragmentation, and circadian rhythm dysfunction. We evaluate the advantages and disadvantages of each model and discuss sex differences in sleep and sleep disorders, along with potential mechanisms. We aim to advance our understanding of sleep disorders and facilitate sex-specific interventions.

Gender medicine and sleep disorders: from basic science to clinical research

Several pivotal differences in sleep and sleep disorders are recognized between women and men. This is not only due to changes in hormonal balance during women's reproductive life, such as in pregnancy and menopause. Women are more likely to report insomnia and non-specific symptoms of apneas, such as fatigue or mood disturbance, compared to men. Thus, it is important for clinicians and researchers to take sex and gender differences into account when addressing sleep disorders in order to acknowledge the biology unique to women. We present a narrative review that delves into the primary sleep disorders, starting from basic science, to explore the impact of gender differences on sleep and the current status of research on women's sleep health.

Sex and Sleep Disruption as Contributing Factors in Alzheimer's Disease

Alzheimer's disease (AD) affects more women than men, with women throughout the menopausal transition potentially being the most under researched and at-risk group. Sleep disruptions, which are an established risk factor for AD, increase in prevalence with normal aging and are exacerbated in women during menopause. Sex differences showing more disrupted sleep patterns and increased AD pathology in women and female animal models have been established in literature, with much emphasis placed on loss of circulating gonadal hormones with age. Interestingly, increases in gonadotropins such as follicle stimulating hormone are emerging to be a major contributor to AD pathogenesis and may also play a role in sleep disruption, perhaps in combination with other lesser studied hormones. Several sleep influencing regions of the brain appear to be affected early in AD progression and some may exhibit sexual dimorphisms that may contribute to increased sleep disruptions in women with age. Additionally, some of the most common sleep disorders, as well as multiple health conditions that impair sleep quality, are more prevalent and more severe in women. These conditions are often comorbid with AD and have bi-directional relationships that contribute synergistically to cognitive decline and neuropathology. The association during aging of increased sleep disruption and sleep disorders, dramatic hormonal changes during and after menopause, and increased AD pathology may be interacting and contributing factors that lead to the increased number of women living with AD.

Consensus guidelines on the construct validity of rodent models of restless legs syndrome

Our understanding of the causes and natural course of restless legs syndrome (RLS) is incomplete. The lack of objective diagnostic biomarkers remains a challenge for clinical research and for the development of valid animal models. As a task force of preclinical and clinical scientists, we have previously defined face validity parameters for rodent models of RLS. In this article, we establish new guidelines for the construct validity of RLS rodent models. To do so, we first determined and agreed on the risk, and triggering factors and pathophysiological mechanisms that influence RLS expressivity. We then selected 20 items considered to have sufficient support in the literature, which we grouped by sex and genetic factors, iron-related mechanisms, electrophysiological mechanisms, dopaminergic mechanisms, exposure to medications active in the central nervous system, and others. These factors and biological mechanisms were then translated into rodent bioequivalents deemed to be most appropriate for a rodent model of RLS. We also identified parameters by which to assess and quantify these bioequivalents. Investigating these factors, both individually and in combination, will help to identify their specific roles in the expression of rodent RLS-like phenotypes, which should provide significant translational implications for the diagnosis and treatment of RLS.

Restless legs syndrome and quality of life in pregnant women

OBJECTIVE

In this study, we aimed to determine the extent of restless legs syndrome (RLS) in pregnant women and evaluate the relationship between the syndrome and quality of life.

METHODS

This is a cross-sectional descriptive study. A questionnaire developed by the researcher, the Short Form 36 (SF-36) Questionnaire to measure the quality of life, the International Restless Legs Syndrome Study Group (IRLSSG) Diagnostic Criteria for RLS and the Restless Legs Syndrome Rating Scale were applied to the women to collect the data. A total of 250 pregnant women were included in the study.

RESULTS

The mean age of the women was 28.11 ± 5.59 years and the mean gestational time was 26.26 ± 10.72 weeks. Symptoms of RLS were seen in 46.4 % of the women. The mean for the RLS Violence Rating Score was 20.82 ± 6.61 for the women with RLS. RLS was found to be mild in 5.2 % of the women, moderate in 45.7 %, severe in 40.5 % and very severe in 8.6 %. A statistically significant effect of RLS survival on quality of life was observed.

CONCLUSION

These results indicate that almost half of the pregnant women in this study experienced RLS, and about half of those with RLS experienced severe or very severe RLS. There is a significant relationship between RLS and six domains of SF-36 (physical, role limitations, pain, general health perception, energy/vitality, and mental health).

The association between obesity and restless legs syndrome: A systemic review and meta-analysis of observational studies

OBJECTIVE

Restless legs syndrome (RLS) has been reported to occur more frequently in obese individuals than in those with normal weight. In this study, a systematic review and meta-analysis was performed to explore the relationship between obesity and RLS.

METHODS

Published articles were identified through a comprehensive review of PUBMED and EMBASE from inception to the 16th December 2017. Data from studies reporting relative risks, odds ratios, or hazard ratios comparing the risk of RLS among individuals with obesity versus people with normal weight were analyzed. A random-effect model was used to calculate pooled odds ratios and 95% confident intervals (CI) for the association between obesity and RLS.

RESULTS

Findings for a total of 197,204 participants were pooled across 15 studies and were examined. Our analyses demonstrated a positive association between obesity and RLS, with an odds ratio (OR) of 1.44 (95%CI: 1.31-1.58, I² = 62.3%). Overweight subjects were also likely to have RLS, with an odds ratio of 1.29 (95%CI: 1.22-1.36, I² = 0). In subgroup analysis, women (OR = 1.42) with obesity were more likely to have RLS as compared with men (OR = 1.19).

CONCLUSIONS

Adults with obesity are more likely to suffer from RLS, with women at higher risk.

The prevalence of restless legs syndrome and its relationship with demographic characteristics and medical disorders in postmenopausal Iranian women

This study was conducted to evaluate the prevalence of restless legs syndrome (RLS) and its relationship with demographic factors and medical disorders on 980 postmenopausal women. Data was gathered using a demographic questionnaire and the International Restless Legs Syndrome Scale. The prevalence of RLS was 16.02% (157/980). Women with poor economic status were 3.37 and 2.33 times more likely to have RLS than women with a good economic situation and moderate economic status (CI:2.041-5.579, P ≤ 0.0001) and (CI: 1.540-3.551, P ≤ 0.0001) respectively. The risk of RLS was 64% greater in women who smoked than in non-smokers. Women with history of hypertension, diabetes and anemia were 2.82, 2.09 and 2.19 times, respectively, more likely to have RLS than those without (P < 0.001). Also women with higher body mass index were more likely to have RLS and women taking hormone replacement therapy were less likely to have RLS. The prevalence of RLS among postmenopausal Iranian women is quite high and there is a relationship between RLS and factors such as age at menopause, education level, a history of smoking, hypertension, anemia and diabetes.

Investigation of alexithymia and levels of anxiety and depression among patients with restless legs syndrome

PURPOSE

The purpose of this study was to examine alexithymia among restless legs syndrome (RLS) patients, compare with healthy controls, and argue the clinical inferences of this relationship. We searched for anxiety and depression and their clinical outcomes among patients and searched whether the results are similar to previous studies.

PATIENTS AND METHODS

Eighty-seven RLS patients and 88 age, gender, and educationally matched healthy controls were assessed in Bezmialem Foundation University Hospital. RLS patients and healthy controls were assessed with the Sociodemographic Data Form constructed for the present study, 20-item Toronto Alexithymia Scale (TAS-20), Beck Depression Inventory (BDI), and Beck Anxiety Scale (BAS). The patient group was also assessed with the International Restless Legs Syndrome Study Group (IRLSSG) RLS Severity Scale.

RESULTS

RLS patients were found to have greater TAS-20, BDI, and BAS scores compared with the control group (P < 0.05). RLS severity score was positively correlated with the scores of anxiety and depression scales. However, no significant relationship was found between scores of IRLSSG RLS scale and TAS-20 total and subscale scores.

CONCLUSION

RLS patients were found to be more alexithymic than healthy controls, whereas no significant relationship was found between RLS severity and levels of alexithymia. Still, alexithymia might be a predictor for early diagnosis and may be considered in the treatment and follow-up of RLS. RLS patients have higher depression and anxiety scores than healthy individuals. Thus, depression and anxiety should be taken into consideration throughout the RLS treatment.

Not only limbs in atypical restless legs syndrome

Restless legs syndrome (RLS) typically affects the limbs, but the involvement of other body parts has also been reported. In this essay, we critically review all literature reports of atypical RLS cases with unusual localizations. Applying the updated diagnostic criteria of the International restless legs syndrome study group (IRLSSG), which also consider symptoms localized outside of the lower limbs, a few of these atypical cases reported in the previous literature resulted in a definitive diagnosis of RLS. We also discuss the relationship between RLS and burning mouth syndrome (BMS) or restless genital syndrome (RGS). We conclude clinical sleep specialists should be aware of unusual RLS localizations because they respond to the usual treatment for RLS. All the IRLSSG diagnostic criteria should be applied in every suspected case, in order to establish a correct diagnosis of this disabling but treatable condition.

The Association of Restless Legs Syndrome to History of Gestational Diabetes in an Appalachian Primary Care Population

OBJECTIVES

Restless legs syndrome (RLS) is a burdensome sensorimotor disorder that has been linked to diabetes and obesity. However, the relationship of RLS to gestational diabetes mellitus (GDM), a common pregnancy complication strongly associated with obesity and a harbinger of diabetes, remains unknown. In this study, we examined the association of RLS to history of GDM in a sample of older female primary care patients.

METHODS

Participants were community-dwelling women aged ≥ 40 years drawn from an anonymous survey study of West Virginia adult primary care patients. Data gathered included detailed information on demographics, lifestyle factors, reproductive history, sleep patterns, and medical history; the survey also included an RLS diagnostic questionnaire. Women who were pregnant or had missing data on key variables were excluded from the analyses.

RESULTS

Of the 498 participants included in the final analytic sample, 24.5% met diagnostic criteria for RLS (17.9% with symptoms at least once/week). After adjustment for demographics, lifestyle characteristics, body mass index, diabetes and other comorbid conditions, parity, and other factors, those reporting history of GDM were almost three times as likely to meet criteria for RLS (odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.3, 5.3). This association increased in magnitude with increasing symptom frequency (adjusted OR for RLS symptoms ≥ 3×/week = 4.8, CI 2.1, 11.2, p for trend = 0.004).

CONCLUSIONS

History of GDM was strongly and positively related to RLS in this study of older female primary care patients, offering further support for a possible role of metabolic dysregulation in RLS development.

The Effects of a Gentle Yoga Program on Sleep, Mood, and Blood Pressure in Older Women with Restless Legs Syndrome (RLS): A Preliminary Randomized Controlled Trial

Objective. To examine the effects of yoga versus an educational film program on sleep, mood, perceived stress, and sympathetic activation in older women with RLS. Methods. Participants were drawn from a larger trial regarding the effects of yoga on cardiovascular disease risk profiles in overweight, sedentary postmenopausal women. Seventy-five women were randomized to receive either an 8-week yoga (n = 38) or educational film (n = 37) program. All 75 participants completed an RLS screening questionnaire. The 20 women who met all four diagnostic criteria for RLS (n = 10 yoga, 10 film group) comprised the population for this nested study. Main outcomes assessed pre- and post-treatment included: sleep (Pittsburgh Sleep Quality Index), stress (Perceived Stress Scale), mood (Profile of Mood States, State-Trait Anxiety Inventory), blood pressure, and heart rate. Results. The yoga group demonstrated significantly greater improvements than controls in multiple domains of sleep quality and mood, and significantly greater reductions in insomnia prevalence, anxiety, perceived stress, and blood pressure (all P's≤0.05). Adjusted intergroup effect sizes for psychosocial variables were large, ranging from 1.9 for state anxiety to 2.6 for sleep quality. Conclusions. These preliminary findings suggest yoga may offer an effective intervention for improving sleep, mood, perceived stress, and blood pressure in older women with RLS.

[Quality of sleep and serum lipid profile in patients with restless legs syndrome]

PURPOSE

The purpose of this study was to compare the quality of sleep with the serum lipid profile in patients who have restless legs syndrome (RLS).

METHODS

The data were obtained from 116 patients with RLS through questionnaires and blood sampling.

RESULTS

The results of this study showed correlations between lower quality of sleep and serum lipid profile (LDL Cholesterol) in patients with RLS (r=.19, p=.040). There were correlations for scores of quality of sleep from the, Pittsburgh Sleep Quality Index (PSQI) sub-region between lower subjective sleep quality and serum lipid profile (LDL Cholesterol) (r=.20, p=.026), between fewer hours of sleep duration and serum lipid profile (Total Cholesterol) (r=-.21, p=.024), and, between higher daytime dysfunction and serum lipid profile (LDL Cholesterol) (r=.42, p<.001) of patients with RLS.

CONCLUSION

Patients with RLS have sleep disorders with lower quality of sleep and changes in the serum lipid profile for total cholesterol and LDL cholesterol. That is, patients with RLS have lower quality of sleep and dyslipidemia compared to persons without RLS. Further research is needed to monitor serum the lipid profile in early stage symptoms of midlife adult patients with RLS and especially older women.

Evaluation of contributing factors to restless legs syndrome in migraine patients

Recent studies have provided evidence for a positive association between migraine and restless legs syndrome (RLS), although the exact mechanisms and contributing factors remain unclear. A cross-sectional, case-control study was conducted, including patients with migraine (n = 262) and headache-free control subjects (n = 163). Migraine was diagnosed according to International Classification of Headache Disorders II criteria. RLS diagnosis was made based on four essential criteria as described by the International Restless Legs Syndrome Study Group. All patients completed the Migraine Disability Assessment (MIDAS) questionnaire, Beck Depression Inventory (BDI)-II scores, Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS). A total of 210 blood samples were collected to correlate various parameters with RLS. RLS frequency was significantly greater in patients with migraine than in controls (13.7 vs. 1.8%). Migraine patients with RLS had high scores for MIDAS, BDI-II, PSQI, and ESS compared with those without RLS. In addition, migraine patients with RLS had a high rate of smoking and RLS family history, as well as increased levels of serum phosphorus and urea nitrogen compared with those without RLS. However, there was no difference in serum iron and ferritin levels between the groups. In migraine patients, logistic regression analysis revealed that positive RLS family history, BDI-II, ESS, and serum phosphorus levels were significant RLS predictors. Our study confirmed a positive association between RLS and migraine. RLS comorbidity in migraine patients was associated with insomnia, daytime sleepiness, depressive symptoms, headache-related disability, and increased serum phosphorus levels. These findings may provide a better understanding of RLS pathogenesis in migraine.

Restless legs syndrome during pregnancy in Brazilian women

OBJECTIVE

The objective of this study was to identify the prevalence of restless legs syndrome (RLS) among pregnant Brazilian women, with individual diagnostic clinical interviews during the trimesters of pregnancy, and to determine the severity.

METHODS

It was a cross-sectional study. We interviewed 524 pregnant women (18-45 years old) who came to the prenatal outpatient clinic to consult an obstetrician. We used a RLS clinical-diagnostic interview and the International RLS Study Group rating scale (IRLS).

RESULTS

The prevalence of RLS during pregnancy was 13.5% in our sample, among which 90.1% of the cases started with their symptoms during pregnancy. More than half of the patients (53.5%) presented severe or very severe symptoms and the largest proportion of them (15.2%) were in their third trimester. We did not observe any demographic differences among the trimesters for RLS prevalence and RLS severity.

CONCLUSION

RLS during pregnancy is more frequent than in the general population, such that more than half of the pregnant women with RLS present it severely or very severely. It occurs especially in the third trimester.

[Epidemiology of restless legs syndrome]

INTRODUCTION

Restless legs syndrome (RLS) is a chronic sensorimotor disorder where patients complain of an almost irresistible urge to move their legs. This urge can often be accompanied by pain or other unpleasant sensations, it either occurs or worsens with rest particularly at night, and improves with activity. The International Restless Legs Syndrome Study Group has established four essential criteria for clinical diagnosis of RLS.

STATE OF ART

Affecting an estimated 7.2 to 11.5% of the adult population, the symptoms of RLS may be associated with significant sleep disturbance and may have a negative impact on quality of life. The prevalence of RLS increases with age, and women are more frequently affected than men. In France, the estimated prevalence is 8.5%. Among sufferers, 4.4% complain of very severe symptoms. Although RLS is mainly idiopathic, several clinical conditions have been associated with it, especially iron deficiency with or without anemia, end-stage renal disease and pregnancy. These conditions may share a common pathophysiological mechanism involving a disorder of iron metabolism. By contrast, controversy persists as to whether polyneuropathy, particularly when associated with diabetes, is to be considered as an important cause of secondary RLS. This association is difficult to demonstrate as conventional electromyography is not adequate to detect small fiber neuropathy often associated with diabetes.

CONCLUSION AND PERSPECTIVES

RLS is often underdiagnosed and few subjects receive recommended RLS drug treatment. There is a clear need for complementary education to improve the accurate diagnosis of RLS. Indeed, better knowledge of this syndrome is a prerequisite to prompt an appropriate therapeutic management.

Sleep disorders and their impacts on healthy, dependent, and frail older adults

BACKGROUND

Sleep disorders differ widely in the heterogeneous older adult population. Older adults can be classified into three groups based upon their overall level of disability: healthy, dependent, and frail. Frailty is an emerging concept that denotes older persons at increased risk for poor outcomes.

OBJECTIVE

The aim of this consensus review is to describe the sleep disorders observed in healthy and dependent older adults and to discuss the potential sleep disorders associated with frailty as well as their potential consequences on this weakened population.

METHODS

A review task force was created including neurologists, geriatricians, sleep specialists and geriatric psychiatrists to discuss age related sleep disorders depending on the three categories of older adults. All published studies on sleep in older adults on Ovid Medline were reviewed and 106 articles were selected for the purpose of this consensus.

RESULTS

Many healthy older adults have complains about their sleep such as waking not rested and too early, trouble falling asleep, daytime napping, and multiple nocturnal awakenings. Sleep architecture is modified by age with an increased percentage of time spent in stage one and a decreased percentage spent in stages three and four. Insomnia is frequent and its mechanisms include painful medical conditions, psychological distress, loss of physical activity and iatrogenic influences. Treatments are also involved in older adults' somnolence. The prevalence of primary sleep disorders such as restless legs syndrome, periodic limb movements and sleep disordered breathing increases with age. Potential outcomes relevant to these sleep disorders in old age include mortality, cardiovascular and neurobehavioral co-morbidities. Sleep in dependent older adults such as patients with Alzheimer Disease (AD) is disturbed. The sleep patterns observed in these patients are often similar to those observed in non-demented elderly but alterations are more severe. Nocturnal sleep disruption and daytime sleepiness are the main problems. They are the results of Sleep/wake circadian rhythm disorders, environmental, psychological and iatrogenic factors. They are worsened by other sleep disorders such as sleep disordered breathing. Sleep in frail older adults per se has not yet been formally studied but four axes of investigation should be considered: i) sleep architecture abnormalities, ii) insomnia iii) restless legs syndrome (RLS), iv) sleep disordered breathing.

CONCLUSION

Our knowledge in the field of sleep disorders in older adults has increased in recent years, yet some groups within this heterogeneous population, such as frail older adults, remain to be more thoroughly studied and characterized.

Elevated estradiol plasma levels in women with restless legs during pregnancy

STUDY OBJECTIVES

Pregnant women have an increased risk of experiencing restless legs syndrome (RLS). Aim of this study was to elucidate the relationship between pregnancy-related hormonal and metabolic changes and RLS symptomatology.

DESIGN

Blood measurements and overnight polysomnography were performed during the third trimester of pregnancy and again 3 months after delivery. We investigated blood hormonal levels (estradiol, prolactin, progesterone, testosterone, follicle-stimulating hormone [FSH], luteinizing hormone [LH], iron, ferritin, hemoglobin) and polysomnographic sleep parameters. Subjective sleep quality and RLS symptoms were evaluated using the Pittsburgh Sleep Quality Index (PSQI) and the International RLS study group (IRLSSG) rating scale.

SETTING

Sleep laboratory.

PARTICIPANTS

Ten pregnant women fulfilling the IRLSSG criteria for RLS diagnosis and 9 pregnant healthy controls underwent the protocol.

INTERVENTIONS

N/A.

RESULTS

Women with RLS showed higher levels of estradiol during pregnancy compared to controls (34,211 +/- 6397 pg/mL vs. 25,475 +/- 7990 pg/mL, P<0.05). Patients also showed more periodic limb movements (PLMs) before and after delivery, particularly during sleep stage 1 and wakefulness (P<0.05). PLMs decreased postpartum in subjects with RLS only (P<0.05); sleep efficiency increased in women without RLS and remained unchanged in patients (P<0.05). No significant differences were found between groups before or after delivery in plasma concentrations of prolactin, progesterone, testosterone, FSH, LH, iron, ferritin or hemoglobin.

CONCLUSIONS

RLS in pregnant women goes along with transiently increased estradiol levels and PLM indices suggesting that estrogens play a pathophysiological role for triggering RLS symptoms during pregnancy.

[Restless-legs syndrome]

Restless-legs syndrome (RLS) is a sensorimotor disorder, characterized by an irresistible urge to move the legs usually accompanied or caused by uncomfortable and unpleasant sensations. It begins or worsens during periods of rest or inactivity, is partially or totally relieved by movements and is exacerbated or occurs at night and in the evening. RLS sufferers represent 2 to 3% of the general population in Western countries. Supportive criteria include a family history, the presence of periodic-leg movements (PLM) when awake or asleep and a positive response to dopaminergic treatment. The RLS phenotypes include an early onset form, usually idiopathic with a familial history and a late onset form, usually secondary to peripheral neuropathy. Recently, an atypical RLS phenotype without PLM and l-DOPA resistant has been characterized. RLS can occur in childhood and should be distinguished from attention deficit/hyperactivity disorder, growing pains and sleep complaints in childhood. RLS should be included in the diagnosis of all patients consulting for sleep complaints or discomfort in the lower limbs. It should be differentiated from akathisia, that is, an urge to move the whole body without uncomfortable sensations. Polysomnographic studies and the suggested immobilization test can detect PLM. Furthermore, an l-DOPA challenge has recently been validated to support the diagnosis of RLS. RLS may cause severe-sleep disturbances, poor quality of life, depressive and anxious symptoms and may be a risk factor for cardiovascular disease. In most cases, RLS is idiopathic. It may also be secondary to iron deficiency, end-stage renal disease, pregnancy, peripheral neuropathy and drugs, such as antipsychotics and antidepressants. The small-fiber neuropathy can mimic RLS or even trigger it. RLS is associated with many neurological and sleep disorders including Parkinson's disease, but does not predispose to these diseases. The pathophysiology of RLS includes an altered brain-iron metabolism, a dopaminergic dysfunction, a probable role of pain control systems and a genetic susceptibility with nine loci and three polymorphisms in genes serving developmental functions. RLS treatment begins with the elimination of triggering factors and iron supplementation when deficient. Mild or intermittent RLS is usually treated with low doses of l-DOPA or codeine; the first-line treatment for moderate to severe RLS is dopaminergic agonists (pramipexole, ropinirole, rotigotine). In severe, refractory or neuropathy-associated RLS, antiepileptic (gabapentin, pregabalin) or opioid (oxycodone, tramadol) drugs can be used.