Extreme morning chronotypes are often familial and not exceedingly rare: the estimated prevalence of advanced sleep phase, familial advanced sleep phase, and advanced sleep-wake phase disorder in a sleep clinic population.

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.

Periodic limb movements in sleep: Prevalence and associated sleepiness in the Wisconsin Sleep Cohort.

Objectives: Periodic limb movements in sleep (PLMS) are thought to be prevalent in elderly populations, but their impact on quality of life remains unclear. We examined the prevalence of PLMS, impact of age on prevalence, and association between PLMS and sleepiness.

Methods: We identified limb movements in 2335 Wisconsin Sleep Cohort polysomnograms collected over 12 years.

Breathing Disturbances Without Hypoxia Are Associated With Objective Sleepiness in Sleep Apnea.

Study Objectives: To determine whether defining two subtypes of sleep-disordered breathing (SDB) events-with or without hypoxia-results in measures that are more strongly associated with hypertension and sleepiness.

Methods: A total of 1022 participants with 2112 nocturnal polysomnograms from the Wisconsin Sleep Cohort were analyzed with our automated algorithm, developed to detect breathing disturbances and desaturations. Breathing events were time-locked to desaturations, resulting in two indices-desaturating (hypoxia-breathing disturbance index [H-BDI]) and nondesaturating (nonhypoxia-breathing disturbance index [NH-BDI]) events-regardless of arousals.

Longitudinal associations of hypersomnolence and depression in the Wisconsin Sleep Cohort Study.

Background: Hypersomnolence is common in depression, however longitudinal associations of excessive daytime sleepiness (EDS), long habitual sleep duration, and objective sleep propensity with depressive symptomatology are not well established.

Methods: Data from adults participating in the Wisconsin Sleep Cohort Study who had multiple assessments at 4-year intervals were utilized in analyses. Conditional (intrasubject) logistic regression estimated the likelihood of development of depression and three primary hypersomnolence measures: subjective EDS [Epworth Sleepiness Scale (ESS) >10], habitual sleep duration ≥9h/day, and increased physiological sleep propensity [multiple sleep latency test (MSLT) mean sleep latency <8min].

Subjective and Objective Measures of Hypersomnolence Demonstrate Divergent Associations with Depression among Participants in the Wisconsin Sleep Cohort Study.

Study Objectives: To examine associations of depression with habitual sleep duration, daytime sleepiness, and objective sleep propensity in a nonclinical population.

Methods: Data from adults participating in the Wisconsin Sleep Cohort Study were utilized in analyses. There were 1,287 adults (3,324 observations) who were used in the analysis of subjective hypersomnolence measures; 1,155 adults (2,981 observations) were used in the analysis of objective sleep propensity assessed by the multiple sleep latency test (MSLT).

Association of low ferritin with PLM in the Wisconsin Sleep Cohort.

Objective: The origins of periodic leg movements (PLMs), a strong correlate of restless legs syndrome (RLS), are uncertain. This study was performed to assess the relationship between PLMs and peripheral iron deficiency, as measured with ferritin levels corrected for inflammation.

Methods: We included a cross-sectional sample of a cohort study of 801 randomly selected people (n = 1008 assays, mean age 58.

Obstructive sleep apnoea during REM sleep and incident non-dipping of nocturnal blood pressure: a longitudinal analysis of the Wisconsin Sleep Cohort.

Background: Non-dipping of nocturnal blood pressure (BP) is associated with target organ damage and cardiovascular disease. Obstructive sleep apnoea (OSA) is associated with incident non-dipping. However, the relationship between disordered breathing during rapid eye movement (REM) sleep and the risk of developing non-dipping has not been examined.

Coronary heart disease incidence in sleep disordered breathing: the Wisconsin Sleep Cohort Study.

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.

Obstructive sleep apnea during REM sleep and hypertension. results of the Wisconsin Sleep Cohort.

Rationale: Obstructive sleep apnea (OSA) is associated with hypertension.

Objectives: We aimed to quantify the independent association of OSA during REM sleep with prevalent and incident hypertension.

Methods: We included adults enrolled in the longitudinal community-based Wisconsin Sleep Cohort Study with at least 30 minutes of REM sleep obtained from overnight in-laboratory polysomnography.

Periodic leg movements during sleep are associated with polymorphisms in BTBD9, TOX3/BC034767, MEIS1, MAP2K5/SKOR1, and PTPRD.

Study Objectives: To examine association between periodic leg movements (PLM) and 13 single nucleotide polymorphisms (SNPs) in 6 loci known to increase risk of restless legs syndrome (RLS).

Setting: Stanford Center for Sleep Sciences and Medicine and Clinical Research Unit of University of Wisconsin Institute for Clinical and Translational Research.

Patients: Adult participants (n = 1,090, mean age = 59.

Narcolepsy and predictors of positive MSLTs in the Wisconsin Sleep Cohort.

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.

Association of sleep disordered breathing and cognitive deficit in APOE ε4 carriers.

Study Objectives: The aim of the study was to determine whether apolipoprotein E epsilon 4 genotype (APOE4) modifies the association of sleep disordered breathing (SDB) with cognitive function in a middle-aged population.

Design: Cross-sectional analysis of a community-dwelling cohort.

Settings: Sleep laboratory at the Clinical Research Unit of the University of Wisconsin Hospitals and Clinics.

Unique sleep disorders profile of a population-based sample of 747 Hmong immigrants in Wisconsin.

Concerns regarding sleep disorders in Hmong immigrants in the US emerged when an astonishingly high mortality rate of Sudden Unexplained Nocturnal Death Syndrome (SUNDS) was documented in Hmong men. Stress, genetics, and cardiac abnormalities interacting with disordered sleep were hypothesized as contributing factors to SUNDS. Most recently, sleep apnea has been implicated in nighttime deaths of Brugada Syndrome.

Sleep-disordered breathing and cancer mortality: results from the Wisconsin Sleep Cohort Study.

Rationale: Sleep-disordered breathing (SDB) has been associated with total and cardiovascular mortality, but an association with cancer mortality has not been studied. Results from in vitro and animal studies suggest that intermittent hypoxia promotes cancer tumor growth.

Objectives: The goal of the present study was to examine whether SDB is associated with cancer mortality in a community-based sample.

The impact of ageing and sex on the association between sleepiness and sleep disordered breathing.

The aim of our study was to investigate age-related changes in sleepiness symptoms associated with sleep disordered breathing (SDB). Wisconsin Sleep Cohort participants were assessed using polysomnography, the Epworth Sleepiness Scale (ESS) and the multiple sleep latency test (MSLT). SDB was defined as an apnoea/hypopnoea index ≥15 events·h(-1), and sleepiness as ESS ≥10 and MSLT ≤5 min.

Post-streptococcal antibodies are associated with metabolic syndrome in a population-based cohort.

Background: Streptococcal infections are known to trigger autoimmune disorders, affecting millions worldwide. Recently, we found an association between post-streptococcal autoantibodies against Protein Disulphide Isomerase (PDI), an enzyme involved in insulin degradation and insulin resistance. This led us to evaluate associations between post-streptococcal antibodies and metabolic syndrome, as defined by the updated National Cholesterol Education Program definition, 2005.

β2 adrenergic receptor polymorphisms and nocturnal blood pressure dipping status in the Wisconsin Sleep Cohort Study.

Nondipping nocturnal blood pressure (BP) is associated with target organ damage and cardiovascular disease. We hypothesized that β1- and β2-AR-associated single nucleotide polymorphisms (SNPs) would associate with nondipping BP patterns. Participants (n = 497, age range 30-74 years, 40% female) of the Wisconsin Sleep Cohort Study with at least one ambulatory BP monitoring test were included.

Post-streptococcal auto-antibodies inhibit protein disulfide isomerase and are associated with insulin resistance.

Post-streptococcal autoimmunity affects millions worldwide, targeting multiple organs including the heart, brain, and kidneys. To explore the post-streptococcal autoimmunity spectrum, we used western blot analyses, to screen 310 sera from healthy subjects with (33%) and without (67%) markers of recent streptococcal infections [anti-Streptolysin O (ASLO) or anti-DNAse B (ADB)]. A 58 KDa protein, reacting strongly with post-streptococcal sera, was identified as Protein Disulfide Isomerase (PDI), an abundant protein with pleiotropic metabolic, immunologic, and thrombotic effects.

Effects of sleep-disordered breathing on cerebrovascular regulation: A population-based study.

Rationale: Cerebrovascular regulation is impaired in patients with moderate to severe obstructive sleep apnea; however, it is unknown whether this impairment exists in individuals with less severe sleep-disordered breathing.

Objectives: To test the hypothesis that cerebrovascular responses to hypercapnia are attenuated in a nonclinical population-based cohort.

Methods: A rebreathing test that raised end-tidal CO₂ tension by 10 mm Hg was performed during wakefulness in 373 participants of the Wisconsin Sleep Cohort.

Prospective associations of insomnia markers and symptoms with depression.

Whether insomnia, a known correlate of depression, predicts depression longitudinally warrants elucidation. The authors examined 555 Wisconsin Sleep Cohort Study participants aged 33-71 years without baseline depression or antidepressant use who completed baseline and follow-up overnight polysomnography and had complete questionnaire-based data on insomnia and depression for 1998-2006. Using Poisson regression, they estimated relative risks for depression (Zung scale score > or =50) at 4-year (average) follow-up according to baseline insomnia symptoms and polysomnographic markers.

Dissociation of obstructive sleep apnea from hypersomnolence and obesity in patients with stroke.

Background And Purpose: Obstructive sleep apnea (OSA) is seldom considered in the diagnostic investigation in the poststroke period although it is a stroke risk factor and has adverse prognostic implications after stroke. One reason might be that widely used clinical criteria for detection of OSA in the general community are not applicable in patients with stroke. We hypothesized that patients with stroke report less sleepiness and are less obese than subjects from a community sample with the same severity of OSA.

Sleep disordered breathing and mortality: eighteen-year follow-up of the Wisconsin sleep cohort.

Background: Sleep-disordered breathing (SDB) is a treatable but markedly under-diagnosed condition of frequent breathing pauses during sleep. SDB is linked to incident cardiovascular disease, stroke, and other morbidity. However, the risk of mortality with untreated SDB, determined by polysomnography screening, in the general population has not been established.

Longitudinal association of sleep-disordered breathing and nondipping of nocturnal blood pressure in the Wisconsin Sleep Cohort Study.

Study Objectives: The association of sleep-disordered breathing (SDB) and blunting of normal nocturnal lowering of blood pressure (BP) (nondipping) has only been examined cross-sectionally. The purpose of this study is to investigate whether SDB is prospectively associated with nondipping.

Methods: The longitudinal association between SDB and incident nondipping was examined in a subsample of 328 adults enrolled in the Wisconsin Sleep Cohort Study who completed 2 or more 24-hour ambulatory BP studies over an average of 7.

Electrocardiographically indicated cardiovascular disease in sleep-disordered breathing.

The evidence for a role of sleep-disordered breathing (SDB) in cardiovascular disease (CVD) is inconclusive and limited to clinic-based studies or population-based studies using historical CVD data. The authors investigated cross-sectional association of SDB, assessed by overnight polysomnography and described by frequency of apnea/hypopnea episodes (Apnea-Hypopnea Index, AHI), with screen-detected CVD consisting of cardiologist-confirmed, electrocardiographically indicated coronary artery disease (ECG-CAD), left ventricular hypertrophy (ECG-LVH), arrhythmias, and conduction abnormalities in a general population. Using multiple logistic regression with adjustments for covariables, there was no significant association of AHI with ECG-CAD, ECG-LVH by voltage, arrhythmias, or conduction abnormalities.