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Study Objectives: Report the first prevalence estimates of advanced sleep phase (ASP), familial advanced sleep phase (FASP), and advanced sleep-wake phase disorder (ASWPD). This can guide clinicians on the utility of screening for extreme chronotypes both for clinical decision-making and to flag prospective participants in the study of the genetics and biology of FASP., Methods: Data on morning or evening sleep schedule preference (chronotype) were collected from 2422 new patients presenting to a North American sleep center over 9.8 years. FASP was determined using a severity criterion that has previously identified dominant circadian mutations in humans. All patients were personally seen and evaluated by one of the authors (C.R.J.)., Results: Our results demonstrate an ASP prevalence of 0.33%, an FASP prevalence of 0.21%, and an ASWPD prevalence of at least 0.04%. Most cases of young-onset ASP were familial., Conclusions: Among patients presenting to a sleep clinic, conservatively 1 out of every 300 patients will have ASP, 1 out of every 475 will have FASP, and 1 out of every 2500 will have ASWPD. This supports obtaining a routine circadian history and, for those with extreme chronotypes, obtaining a family history of circadian preference. This can optimize treatment for evening sleepiness and early morning awakening and lead to additional circadian gene discovery. We hope these findings will lead to improved treatment options for a wide range of sleep and medical disorders in the future., (© Sleep Research Society 2019. Published by Oxford University Press [on behalf of the Sleep Research Society]. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Study Objectives: The aim of the study was to determine the association of objectively measured sleep disordered breathing (SDB) with incident coronary heart disease (CHD) or heart failure (HF) in a nonclinical population., Design: Longitudinal analysis of a community-dwelling cohort followed up to 24 y., Setting: Sleep laboratory at the Clinical Research Unit of the University of Wisconsin Hospital and Clinics., Participants: There were 1,131 adults who completed one or more overnight polysomnography studies, were free of CHD or HF at baseline, were not treated by continuous positive airway pressure (CPAP), and followed over 24 y., Interventions: None., Measurements and Results: In-laboratory overnight polysomnography was used to assess SDB, defined by the apnea-hypopnea index (AHI) using apnea and hypopnea events per hour of sleep. Incident CHD or HF was defined by new reports of myocardial infarction, coronary revascularization procedures, congestive heart failure, and cardiovascular deaths. We used baseline AHI as the predictor variable in survival analysis models predicting CHD or HF incidence adjusted for traditional confounders. The incidence of CHD or HF was 10.9/1,000 person-years. The mean time to event was 11.2 ± 5.8 y. After adjusting for age, sex, body mass index, and smoking, estimated hazard ratios (95% confidence interval) of incident CHD or HF were 1.5 (0.9-2.6) for AHI > 0-5, 1.9 (1.05-3.5) for AHI 5 ≤ 15, 1.8 (0.85-4.0) for AHI 15 ≤ 30, and 2.6 (1.1-6.1) for AHI > 30 compared to AHI = 0 (P trend = 0.02)., Conclusions: Participants with untreated severe sleep disordered breathing (AHI > 30) were 2.6 times more likely to have an incident coronary heart disease or heart failure compared to those without sleep disordered breathing. Our findings support the postulated adverse effects of sleep disordered breathing on coronary heart disease and heart failure., (© 2015 Associated Professional Sleep Societies, LLC.)

Study Objectives: To study whether positive multiple sleep latency tests (MSLTs, mean sleep latency [MSL] ≤ 8 minutes, ≥ 2 sleep onset REM sleep periods [SOREMPs]) and/or nocturnal SOREMP (REM sleep latency ≤ 15 minutes during nocturnal polysomonography [NPSG]) are stable traits and can reflect incipient narcolepsy., Design and Setting: Cross-sectional and longitudinal investigation of the Wisconsin Sleep Cohort Study., Participants: Adults (44% females, 30-81 years) underwent NPSG (n = 4,866 in 1,518 subjects), and clinical MSLT (n = 1,135), with 823 having a repeat NPSG-MSLT at 4-year intervals, totaling 1725 NPSG with MSLT studies. Data were analyzed using linear mixed-effects models, and the stability of positive MSLTs was explored using κ statistics., Measurements and Results: Prevalence of a nocturnal SOREMP on a NPSG, of ≥ 2 SOREMPs on the MSLT, of MSL ≤ 8 minutes on the MSLT, and of a positive MSLT (MSL ≤ 8 minutes plus ≥ 2 SOREMPs) were 0.35%, 7.0%, 22%, and 3.4%, respectively. Correlates of a positive MSLT were shift work (OR = 7.8, P = 0.0001) and short sleep (OR = 1.51/h, P = 0.04). Test-retest for these parameters was poor, with κ < 0.2 (n.s.) after excluding shift workers and short sleepers. Excluding shift-work, short sleep, and subjects with negative MSLTs, we found one undiagnosed subject with possible cataplexy (≥ 1/month) and a NPSG SOREMPs; one subject previously diagnosed with narcolepsy without cataplexy with 2 NPSG SOREMPs and a positive MSLT, and two subjects with 2 independently positive MSLTs (66% human leukocyte antigen [HLA] positive). The proportions for narcolepsy with and without cataplexy were 0.07% (95% CI: 0.02-0.37%) and 0.20% (95% CI: 0.07-0.58%), respectively., Conclusions: The diagnostic value of multiple sleep latency tests is strongly altered by shift work and to a lesser extent by chronic sleep deprivation. The prevalence of narcolepsy without cataplexy may be 3-fold higher than that of narcolepsy-cataplexy.

Study Objectives: Daytime sleepiness is a pervasive problem that is associated with a significant public-health burden. Although self-reported measures of daytime sleepiness may be useful in identifying at-risk individuals, there is significant controversy because there are no population-based data relating subjective and objective measures of daytime sleep tendency. The aims of this study were to examine the associations between the Multiple Sleep Latency Test (MSLT), an objective measure of daytime sleep tendency, and self-reported information on the Epworth Sleepiness Scale (ESS) and nighttime sleep duration in the general population., Design: Cross-sectional study., Setting and Participants: Population-based sample of 261 women and 371 men, mean age of 50.8 years, enrolled in the Wisconsin Sleep Cohort Study., Measurements: MSLT, ESS, and self-reported sleep duration prior to the MSLT., Results: Using survival analysis to model the time to sleep onset during the MSLT, we found that individuals with an intermediate (6-11) and high (> or = 12) ESS score had a 30% and 69% increase in risk for sleep onset during the MSLT, respectively, compared to individuals with a low ESS score (< or = 5). A dose-response relationship between self-reported duration of nighttime sleep and objective sleep tendency was also observed. Compared to individuals reporting more than 7.50 hours of sleep (highest tertile), individuals reporting 6.75 to 7.50 hours and less than 6.75 hours (lowest tertile) had a 27% and 73% increase in risk for sleep onset during the MSLT, respectively., Conclusions: Subjective reports of daytime sleep tendency on the ESS and the duration of nighttime sleep are associated with the results of the MSLT in the general population.

Study Objective: Assess objectively measured sleep quality in premenopausal, perimenopausal, and postmenopausal women., Design: Observational epidemiology study., Setting: Community-based., Participants: Probability sample of 589 premenopausal, perimenopausal, and postmenopausal women recruited from state employee records., Interventions: None., Measurements and Results: Menopausal status was determined by menstrual history, surgical history, and use of hormone replacement therapy. Sleep quality was objectively measured by full in-laboratory polysomnography and by self-reported sleep problems. Linear and logistic regression were used to estimate associations adjusted for potential confounding factors., Objective: Sleep quality was not worse in perimenopausal or postmenopausal women, compared with premenopausal women. To the contrary, postmenopausal woman had more deep sleep (16% vs 13% stages 3/4, P < 0.001) and significantly longer total sleep time (388 minutes vs 374 minutes, P = 0.05). Menopausal status was moderately related to self-reported dissatisfaction with sleep but was not consistently associated with symptoms of insomnia or sleepiness., Conclusions: Menopause is not associated with diminished sleep quality measured by polysomnography. Although perimenopausal and postmenopausal women, relative to premenopausal women, were less satisfied with their sleep, menopause was not a strong predictor of specific sleep-disorder symptoms. Symptoms and signs of sleep abnormalities in midlife women should not be attributed primarily to menopause before ruling out underlying sleep disorders.

Objective: To determine clinicians' patterns of use of the International Classification of Sleep Disorders (ICSD) and their ratings of its utility and organization., Methods: A telephone survey was conducted in one clinician practicing at each of 206 sleep centers accredited by the American Academy of Sleep Medicine (AASM). Descriptive analyses were performed, and ratings for various sleep classifications were compared with ANOVA and post- hoc tests., Results: Clinicians at 230/251 (92%) of contacted centers agreed to participate, and data from 206/251 (82%) were actually collected. The ICSD was used by 91.7% of clinicians for clinical decision making but by lower percentages for billing or medical record keeping. Features of the ICSD pertaining to clinical descriptions and differential diagnosis were rated as most useful. The Association of Sleep Disorders Centers (ASDC) classification was rated more highly than ICSD in organization and ease of use. The ICSD and ASDC systems were rated more highly than other sleep disorders classifications in terms of organization, "fit" to patients, and ease of use., Conclusions: The ICSD is used widely by clinicians, primarily for diagnostic purposes, and is preferred over more general sleep disorders classification systems. However, more favorable ratings for the ASDC compared to ICSD indicate the value clinicians place on easy-to-use, symptom-oriented classifications.

Study Objectives: To determine the short-term variability of indices of disturbed respiration and sleep during 2 nights of unattended nonlaboratory polysomnography conducted several months apart., Design: Participants were randomly selected using a block design with stratification on preliminary estimates of 2 criteria: respiratory disturbance index [RDI3% (apnea or hypopnea events associated with > or = 3% O2 desaturation): < 15/hour total sleep time, > or = 15/hour total sleep time] and sleep efficiency (SEff: < 85% and > or = 85%). The RDI and sleep data from initial and repeated polysomnography were compared., Setting: NA., Participants: A subset of 99 participants in the Sleep Heart Health Study who agreed to have a repeat polysomnogram within 4 months of their original study., Interventions: NA., Measurements and Results: Acceptable repeat polysomnograms were obtained in 91 subjects (mean study interval: 77 +/- 18 [sd] days; range: 31-112 days). There was no significant bias in RDI between study nights using several different RDI definitions including RDI3% and RDI4% (apnea or hypopnea events associated with > or = 4% O2 desaturation). Variability between studies estimated using intraclass correlations (ICC) ranged from 0.77 to 0.81. For subjects with a RDI3% < 15, variability increased as a function of increasing RDI, but for those with a RDI3% > or = 15, variability was constant. Body mass index, SEff, gender, or age did not directly predict RDI variability. Using RDI4% cutpoints of < or = 5, < or = 10 and < or = 15 events per hour of sleep demonstrated that 79.1%, 85.7%, and 87.9% of subjects, respectively, had the same classification of SDB status on both nights of study. There also was no significant bias in sleep staging, sleep efficiency, or arousal index between studies. However, variability was greater with ICC values ranging from 0.37 (% time in REM) to 0.76 (arousal index)., Conclusion: In the Sleep Heart Health Study, accurate estimates of the severity of sleep-disordered breathing and the quality of sleep were obtained from a single night of unattended nonlaboratory polysomnography. These findings may be applicable to other large epidemiologic studies provided that similar recording techniques and quality-assurance procedures are followed.

Epidemiology studies of SDB and CVD to date do not provide a conclusive answer to the question of the degree to which SDB impacts CVD or mortality due to CVD. However, most of the studies seem to be consistent with a positive, but perhaps small, association. All the findings discussed or referred to in this review are likely to be biased to some degree. Bias can be both towards underestimation (e.g., from mismeasurment of SDB, and over-control for intermediate factors) and overestimation (e.g., from inadequate control of confounders and improper comparison groups), and the net magnitude of competing biases undoubtedly varies from study to study. Small associations were found in the prospective population-based studies, with one exception. The most obvious methodologic problem in these studies would be likely to result in underestimation of the associations. The case-control studies, in contrast, showed large associations, but serious biases in these studies would probably cause overestimation. Small associations of marginal statistical significance were reported from cross-sectional analyses; findings were limited by sample size. Although each individual study to date could be (and has been ) "dismissed" due to weaknesses, collectively they provide evidence that we cannot dismiss the hypothesis that SDB causes CVD. In many cases, the weak associations can be explained by problems that likely cause underestimation. In fact, finding any association with the limitations of most of the past studies is remarkable. Perhaps most important, the findings to date, in conjunction with biologically plausible mechanisms have sparked the interest needed to initiate the large undertaking of a population-based prospective study. The Sleep Heart Health Study (SHHS)15 is a large multicenter prospective study specifically designed to investigate the role of SDB in incident coronary heart disease, stroke, increased blood pressure, and allcause-mortality. A key feature of the study is that home polysomnography studies are performed on a sample of 6600 men and women, 40 years of age and older, drawn from the samples of other longitudinal studies. The new data collected by SHHS can then be linked to the large amount of data on cardiovascular risk factors available from the "parent" studies. All baseline polysomnography studies have now been completed. Cross-sectional analyses of SDB and CVD history are now being analyzed, and collection of outcome data for longitudinal analyses is underway. Results from SHHS and other studies in the near future should greatly increase our ability to assess the association of SDB and CVD.

This report addresses the hypothesis that snoring without significant apneas and hypopneas (simple snoring) is associated with elevated blood pressure and cardiovascular disease (CVD). Data on blood pressure, previously diagnosed cardiovascular disease, and sleep-disordered breathing (SDB) status from a population-based sample of 580 adults was analyzed. Systolic and diastolic blood pressures, adjusted for age, sex, and body mass index, increased stepwise across categories of no SDB, simple snoring, mild, moderate, and more severe SDB (p < 0.05). A similar and significant trend was seen for CVD prevalence. The results provide evidence that simple snoring represents the beginning of the SDB severity spectrum and that simple snoring has a proportionately smaller but, nevertheless, significant, risk for elevated blood pressure and CVD.