Genetic factors in self-reported snoring and excessive daytime sleepiness: a twin study

Subjects in this study included 1,560 intact male-male twin pairs (818 monozygotic [MZ], 742 dizygotic [DZ]) of mean age (+/- SD) 74.2 +/- 2.8 yr. The Epworth Sleepiness Scale (ESS) was used to assess daytime sleepiness and standardized questionnaires assessed snoring. Multivariate genetic model fitting was used to estimate the contribution of genetic and nongenetic (environmental) influences to the variation and covariation of obesity with snoring and daytime sleepiness. In this sample, 26% were habitual snorers, 18% reported excessive daytime sleepiness (ESS > or = 11), and 29% were obese (body mass index [BMI] > or = 28). By using structural equation modeling, we estimated that genetic factors accounted for 64% of the variance in obesity, 40% of the variance in daytime sleepiness, and 23% of the variability in self-reports of snoring. We found a significant genetic correlation between obesity and snoring and between obesity and excessive daytime sleepiness (EDS), although for the most part the genetic variance in snoring and sleepiness was nonoverlapping with the genetic variance for obesity. We conclude from these data that self-reported symptoms of snoring and daytime sleepiness in older men have a genetic basis that is largely independent of genes associated with obesity.     

Sleep-related breathing disorders in obese patients presenting with acute respiratory failure

INTRODUCTION: The study was conducted to assess the clinical and polysomnographic characteristics of patients with sleep-related breathing disorders who presented to the intensive care unit (ICU) with acute respiratory failure and the practicability of performing polysomnography for such patients. MATERIAL AND METHODS: We analyzed clinical presentation, cause of admission to the ICU, ICU course and outcome of 11 subjects with acute respiratory failure who were diagnosed to have sleep disordered breathing based on polysomnography between October 1999 and January 2003. Subjects were compared to 11 patients with obstructive sleep apnea syndrome matched to each subject using body mass index, age and apnea hypopnea index measured at the time of diagnosis (matched comparison group). Repeated arterial blood gases and polysomnography were done for 8 subjects compliant to treatment 6-8 months after discharge from ICU. RESULTS: The reason for ICU admission for all subjects was hypercapnic respiratory failure. pH and daytime PaO2 were significantly lower in studied subjects compared to the matched comparison group while awake daytime PaCO2 was significantly higher. Subjects had frequent episodes of hypoventilation. Follow up arterial blood gases and polysomnography 6-8 months after treatment (non-invasive ventilation) in compliant subjects showed significant improvement in all blood gases parameters. CONCLUSIONS: Early polysomnography (or portable cardio-respiratory monitoring) allows accurate diagnosis and institution of the appropriate ventilation method Further studies should assess the evolution of respiratory drive in patients with sleep disordered breathing and hypercapnia under therapy (non-invasive ventilation).     

Associations of sleep-disordered breathing with excessive daytime sleepiness and blood pressure in Japanese women.

Sleep-disordered breathing (SDB) is a recognized risk factor for excessive daytime sleepiness (EDS) and hypertension, but evidence of this association in Asian women is limited. We conducted a cross-sectional study of 3,568 women aged 30-69 years living in three Japanese communities. The 3% oxygen desaturation index (ODI) was selected as the indicator of SDB, and blood oxygen fall was estimated by overnight pulse oximetry. The prevalence of SDB was 20.2% for 3% ODI>or=5, 6.4% for 3% ODI>or=10, and 2.8% for 3% ODI>or=15 among Japanese women aged 30-69 years. The 3% ODI was positively associated with the prevalence of self-reported EDS and mean values of systolic and diastolic blood pressure levels. The multivariate odds ratios for 3% ODI of 5-9, 10-14, and >or=15 in reference to 3% ODI<5 were 1.9 (1.2-3.0), 2.2 (1.0-4.6), and 1.8 (0.7-4.4) (p for trend=0.01), respectively, for EDS and 1.1 (0.9-1.4), 1.2 (0.8-1.8), and 2.2 (1.4-3.4) (p for trend<0.001), respectively, for hypertension. The severity of SDB was significantly associated with EDS and hypertension among Japanese women.     

Relationships between sleep-disordered breathing and blood pressure and excessive daytime sleepiness among truck drivers.

Sleep-disordered breathing is a risk factor for hypertension, cardiovascular disease and accidents in the general population, but little is known about this correlation among professional truck drivers. To examine the relationships of sleep-disordered breathing with blood pressure levels and excessive daytime sleepiness among truck drivers, we conducted a population-based cross-sectional study of 1,313 subjects aged 20-69 years registered in the Japanese Trucking Association. The 3% oxygen desaturation index was selected as an indicator of sleep-disordered breathing, representing the number of desaturation events per hour of recording time in which blood oxygen fell by > or = 3% by overnight pulse oximetry. The Epworth Sleepiness Scale was used to estimate excessive daytime sleepiness. There were significant positive associations between the 3% oxygen desaturation index levels and both diastolic blood pressure levels and Epworth Sleepiness Scale scores. The multivariate odds ratio of hypertension was 2.0 (1.1-3.6) for a 3% oxygen desaturation index of > or = 15 in reference with a 3% oxygen desaturation index of <5. This association was more evident among those aged > or = 40 years and overweight subjects. Further, the multivariate odds ratio of an Epworth Sleepiness Scale of > or = 11 was 2.3 (1.1-4.9) for a 3% oxygen desaturation index of > or =15 in reference with a 3% oxygen desaturation index of <5. This association was more evident among those aged > or =40 years. The associations of sleep-disordered breathing severity with diastolic blood pressure levels and excessive daytime sleepiness suggest the need for sleep-disordered breathing screening among truck drivers for prevention of hypertension and potential traffic accidents.     

Association of self-reported nasal blockage with sleep-disordered breathing and excessive daytime sleepiness in Pakistani employed adults

Purpose  

To assess prevalence of self-reported nasal congestion and its association with sleep-disordered breathing (SDB) and excessive daytime sleepiness (EDS) in Pakistani adults employed at a medical university.     

Role of snoring and daytime sleepiness in occupational accidents.

To establish whether snoring and excessive daytime sleepiness (EDS), the main symptoms of obstructive sleep apnea syndrome, influence the risk of occupational accidents a population-based, prospective study was performed. In 1984, 2,874 men aged 30-64 answered questions on snoring and EDS. Ten years later 2,009 (73.8% of the survivors) responded to a follow-up questionnaire including work-related questions and potential confounders. Information on occupational accidents during 1985-1994 was obtained from national register data. A total of 345 occupational accidents were reported by 247 of the men (12.3%). Multivariate analysis revealed that men who reported both snoring and EDS at baseline were at an increased risk of occupational accidents during the following 10 yr, with an adjusted odds ratio of 2.2 (95% CI 1.3-3.8) after adjusting for age, body mass index, smoking, alcohol dependence, years at work, blue-collar job, shift work, and exposure to noise, organic solvents, exhaust fumes, and whole-body vibrations. However, no significant increased risk was found for snorers without EDS or nonsnorers with EDS. We conclude that sleepy, male snorers have an increased risk of occupational accidents. The results indicate that early identification and treatment of sleep-disordered breathing may reduce the number of injuries at work.     

Sleep-related breathing disorders in facioscapulohumeral dystrophy

Purpose

Severe manifestations of facioscapulohumeral dystrophy (FSHD) may be associated with sleep-disordered breathing (SDB), including obstructive sleep apnea (OSA) and nocturnal hypoventilation (NH), but prevalence data are scarce. In patients with respiratory muscle weakness, detection of NH can be facilitated by transcutaneous capnometry, but respective data derived from FSHD patients have not yet been published.

Methods

We collected sleep studies and capnometry recordings from 31 adult patients with genetically confirmed FSHD who were admitted to our sleep laboratory for first-ever evaluation of sleep-related breathing. Indications for admission included non-restorative sleep, morning headache, or excessive daytime sleepiness. In addition, sleep studies were initiated if symptoms or signs of respiratory muscle weakness were present. Thirty-one subjects with insomnia served as controls for comparison of respiratory measures during sleep.

Results

In the FSHD group, 17/31 (55%) patients showed OSA and 8 (26%) had NH. NH would have been missed in 7/8 patients if only oximetry criteria of hypoventilation had been applied. Capnography results were correlated with disease severity as reflected by the Clinical Severity Score (CSS). Non-invasive ventilation (NIV) was started in 6 patients with NH and 3 individuals with OSA. Nocturnal continuous positive airway pressure was administered to 2 patients, and positional therapy was sufficient in 4 individuals. In patients initiated on NIV, nocturnal gas exchange already improved in the first night of treatment.

Conclusions

SDB is common in adult patients with FSHD complaining of sleep-related symptoms. It may comprise OSA, NH, and most often, the combination of both. Sleep-related hypercapnia is associated with disease severity. Transcutaneous capnometry is superior to pulse oximetry for detection of NH.

     

Sleep-related breathing disorders and cardiovascular disease

Sleep-related breathing disorders, ranging from habitual snoring to the increased upper airway resistance syndrome to sleep apnea, are now recognized as major health problems. The majority of patients have excessive daytime sleepiness and tiredness. Neuropsychological dysfunction results in poor work performance, memory impairment, and even depression. Until recently, the coexistence of cardiovascular and cerebrovascular diseases with sleep-related breathing disorders was thought to be the result of shared risk factors, such as age, sex, and obesity. However, in the past 5 years several epidemiologic studies have demonstrated that sleep-related breathing disorders are an independent risk factor for hypertension, probably resulting from a combination of intermittent hypoxia and hypercapnia, arousals, increased sympathetic tone, and altered baroreflex control during sleep. Sleep apnea may lead to the development of cardiomyopathy and pulmonary hypertension. Early recognition and treatment of sleep-related breathing disorders may improve cardiovascular function.     

Predictors of objective level of daytime sleepiness in patients with sleep-related breathing disorders

Excessive daytime sleepiness, the most prevalent symptom associated with the OSAS, is hypothesized to result from either fragmentation of sleep or hypoxemia during sleep. Measures of nocturnal sleep, respiration during sleep, and daytime sleepiness in 466 patients with apnea were collected to evaluate these two hypotheses. The various parameters were submitted to correlation and multiple regression analyses to predict daytime sleepiness as measured by the MSLT. The RAI, which measures the number of arousals from sleep associated with respiratory disturbances (best fragmentation correlation), produced a higher correlation with MSLT scores than did TMES (best hypoxemia correlation); however, the measures were highly intercorrelated, and multiple regression analyses to determine which parameters independently predicted MSLT showed the single best predictor to be the RAI. Additional independent variance in MSLT score was explained by TST and PSG1. Measures of hypoxemia provided little or no independent predictive information. These data support the hypothesis that sleep fragmentation is an important determinant of daytime sleepiness in patients with apnea.     

Excessive daytime sleepiness in sleep disorders

Excessive daytime sleepiness is a significant public health problem, with prevalence in the community estimated to be as high as 18%. Sleepiness is caused by abnormal sleep quantity or sleep quality. Amongst others, multiple neurological, psychological, cardiac and pulmonary disorders may contribute. Risk factors for excessive sleepiness include obesity, depression, extremes of age and insufficient sleep. In the clinical setting, two of the most commonly encountered causes are obstructive sleep apnoea and periodic limb movement disorder. There is continuing discussion of the mechanisms by which these disorders cause daytime symptoms, with intermittent nocturnal hypoxia, sleep fragmentation and autonomic dysregulation identified as important factors. The increased prevalence of obstructive sleep apnoea in obese subjects does not fully account for the increased rates of daytime sleepiness in this population and there is evidence to suggest that it is caused by metabolic factors and chronic inflammation in obese individuals. Sleepiness is also more common in those reporting symptoms of depression or anxiety disorders and significantly impacts their quality of life. Clinicians should be aware of factors which put their patients at high risk of daytime sleepiness, as it is a debilitating and potentially dangerous symptom with medico-legal implications. Treatment option should address underlying contributors and promote sleep quantity and sleep quality by ensuring good sleep hygiene. However, stimulant medication may be indicated in some cases to allow for more normal daytime functioning.KEY WORDS : Sleep, sleep apnoea, obstructive, nocturnal myoclonus syndrome, obesity, depression     

Functional outcomes of excessive daytime sleepiness in older adults

OBJECTIVES: To describe the effect of self-reported excessive daytime sleepiness (EDS) on functional outcomes. DESIGN: Case-control study designed to examine differences in functional status between cases (with daytime sleepiness) and controls (no daytime sleepiness) with regard to demographic factors, general health, sleep history, and medications. SETTING: Retirement communities in southeastern Pennsylvania, Delaware, and New Jersey. PARTICIPANTS: Seventy-six nondepressed, nondemented adults, aged 65 and older, were cases (had daytime sleepiness) and 38 were controls (had no daytime sleepiness). MEASUREMENTS: Standardized questionnaires to assess disease-specific functional status (Functional Outcomes of Sleepiness Questionnaire (FOSQ) and Epworth Sleepiness Scale (ESS)), depression (Geriatric Depression Scale-Short Form and the Center for Epidemiologic Studies-Depression Scale), dementia (Short Blessed Test), demographic factors, current medical history, and sleep complaints. RESULTS: There was a significant difference in functional status between sleepy cases and nonsleepy controls. Sleepiness had a moderate to large negative effect (effect size range from 0.59 to 0.83, P <.005) on the following functional domains of the FOSQ: social outcome, general productivity, vigilance, activity level, and global assessment of functional status. Correlation between ESS and FOSQ subscales were -0.31 to -0.67, P <.05. Examination of cases with daytime sleepiness revealed increased functional impairment in individuals with more than three medical conditions or those taking more than four medications (P <.001 and P =.03, respectively). CONCLUSION: Daytime sleepiness is associated with functional impairments in a broad range of activities. The decrease in daily functioning noted in the sleepy subjects has implications for deconditioning and related comorbidity. These findings suggest that exploration of daytime sleepiness should be part of the ongoing assessment of the elderly, particularly those with multiple medical conditions.     

Clinical and polysomnographic characteristics of excessive daytime sleepiness in children

Sleep and Breathing - This study aimed to delineate the clinical and polysomnography (PSG) characteristics of sleep disorders in children with excessive daytime sleepiness (EDS). Between February...     

The evaluation of excessive daytime sleepiness in taxi drivers

Excessive daytime sleepiness (EDS) is a common but underrecognized and preventable cause of traffic accidents. It creates a problem of particular importance for professional drivers. We performed the Epworth Sleepiness Scale (ESS) and questionnaire related to their history of traffic accidents to 118 professional taxi drivers to determine the EDS and its effects on driving performance in taxi drivers. There were 58 (49.2%) subjects with loud snoring, 8 (5.9%) subjects with cardinal symptoms due to obstructive sleep apnea syndrome (OSAS) and 28 (23.7%) subjects with ESS > or =10 in the group of taxi drivers. Eighty (67.8%) drivers had been involved in a traffic accident. We found a significant relation between the number of traffic accident and EDS, witnessed apnea, cardinal symptom related to OSAS but not with snoring. The present data that sleepiness is a common symptom in taxi drivers and may be related to traffic accident.     

Is waking electroencephalographic activity a predictor of daytime sleepiness in sleep-related breathing disorders?

No data are available in the literature assessing the potential use of waking electroencephalographic (EEG) activity in the detection of excessive daytime sleepiness (EDS) in patients with sleep-related breathing disorders (SRBD). The aim of this study was to evaluate whether waking EEG spectral power reflects the level of EDS in SRBD patients. The study was performed in 48 patients in whom quantitative EEG analysis, including the alpha attenuation coefficient (AAC), was performed. Sleepiness was assessed by the Epworth Sleepiness Scale, the Stanford Sleepiness Scale, the Visual Analogue Scale and the maintenance of wakefulness test. Although AAC and EEG spectral power tended to vary throughout the day, none of these variations correlated with EDS measures. Waking EEG measures were not different between snorers and apnoeic patients. Compared to nonsleepy patients, sleepy patients had greater theta and slow alpha powers, but the differences did not reach statistical significance. The EEG slowing was independent of hypoxaemia, severity of SRBD, or degree of sleep disruption. The authors conclude that waking electroencephalographic measures are not sensitive enough to predict variation in alertness or to differentiate sleepy from nonsleepy sleep-related breathing disorders patients. The degree of electroencephalographic slowing was related neither to sleep disruption nor to severity of sleep-related breathing disorders.     

Excessive daytime sleepiness and fatigue in neurological disorders

Sleep and Breathing - Excessive daytime sleepiness (EDS) and fatigue are some of the most frequent symptoms in neurological diseases and could impact on quality of life by increasing the risk of...     

Sleep-related disordered breathing during pregnancy in obese women.

STUDY OBJECTIVES: This study was designed to evaluate sleep-related disordered breathing in obese women during pregnancy. Obesity is known to predispose to sleep-related breathing disorders. During pregnancy, obese mothers gain additional weight, but other mechanisms may counteract this effect. DESIGN: A case-control study to compare sleep-related breathing in obese pregnant women (mean prepregnancy body mass index [BMI] > 30 kg/m(2)) with pregnant women of normal weight (mean BMI, 20 to 25 kg/m(2)). SETTING: University teaching hospital with a sleep laboratory. PARTICIPANTS: We recruited 11 obese women (BMI, 34 kg/m(2); mean age 31 years) and 11 control women (BMI, 23 kg/m(2); mean age 32 years). INTERVENTIONS: Overnight polysomnography was performed during early (after 12 weeks) and late (after 30 weeks) pregnancy. MEASUREMENTS AND RESULTS: During pregnancy, obese mothers gained 13 kg and control women gained 16 kg. Sleep characteristics did not differ between the groups. During late pregnancy, the women in both groups slept more poorly and slept in supine position less. During early pregnancy, their apnea-hypopnea indexes (1.7 events per hour vs 0.2 events per hour; p < 0.05), 4% oxygen desaturations (5.3 events per hour vs 0.3 events per hour; p < 0.005), and snoring times (32% vs 1%, p < 0.001) differed significantly. These differences between the groups persisted in the second polysomnography, with snoring time further increasing in the obese. Preeclampsia and mild obstructive sleep apnea were diagnosed in one obese mother. One obese mother delivered a baby showing growth retardation (weight - 3 SD). CONCLUSIONS: We have shown significantly more sleep-related disordered breathing occurring in obese mothers than in subjects of normal weight, despite similar sleeping characteristics.