Physiologic and symptomatic burden across sleep-disordered breathing severity in men and women.

Dynamic instability of breathing during sleep predicts cognition, disease, and mortality.

STUDY OBJECTIVES To test whether an interpretable effort-derived Breathing Stability Index (BSI) captures physiology and clinical risk beyond conventional sleep-disordered breathing metrics. METHODS We analyzed 43,611 overnight polysomnography records from two clinical cohorts and one community cohort. BSI was derived from abdominal and thoracic effort envelopes as a continuous measure of respiratory effort instability. We compared BSI with AHI, hypoxic burden, arousal index, periodic breathing/self-similarity, desaturation frequency, sleep stage, and event phenotype; evaluated cognition and nine matched cross-sectional EHR disease labels; and tested mortality in Cox models. RESULTS BSI increased across AHI severity and tracked comparator metrics while remaining partly nonredundant. In mutually adjusted models, BSI remained associated with periodic breathing, AHI, arousal index, and desaturation index. Within AHI strata, instability was lowest in deeper NREM sleep and higher in lighter sleep and REM sleep. Cognitive associations were cohort dependent and strongest in MrOS, where less stable breathing was associated with worse fluid and total cognition after age/sex adjustment. In matched EHR disease analyses, BSI features provided modest discrimination (AUROC 0.509-0.642) and age/sex-adjusted associations for 8 of 9 labels. BSI was associated with all-cause mortality after adjustment for age, sex, and comparator sleep metrics in Massachusetts General Hospital (HR 1.38 per SD, 95% CI 1.23-1.54) and Beth Israel Deaconess Medical Center (HR 1.10, 95% CI 1.02-1.19), but not MrOS. CONCLUSIONS Nocturnal breathing stability captures dynamic sleep-disordered breathing physiology that complements event counts and desaturation metrics and relates to cognition, cross-sectional disease labels, and cohort-dependent survival risk.

Regional Disruption of Slow-Wave Sleep Homeostasis in Children with Sleep-Disordered Breathing

Importance Sleep-disordered breathing (SDB) is common in childhood and is associated with attentional and behavioral impairments despite largely preserved sleep macrostructure and minimal abnormalities in conventional electroencephalographic measures. This discrepancy has contributed to the perception that sleep is relatively preserved in pediatric SDB and has limited understanding of the physiological mechanisms underlying morbidity. Objective To determine whether pediatric SDB is associated with disruption of the regional organization and homeostatic dynamics of slow-wave activity (SWA), a key physiological marker of sleep-dependent neural recovery and development. Design, Setting, and Participants Cross-sectional study of 62 children aged 4 to 12 years who underwent overnight polysomnography with high-density electroencephalography in a laboratory setting. Participants were recruited from clinical referrals and the community, spanning the full spectrum of SDB severity. Exposures SDB severity indexed by hypopnea index (HI), apnea-hypopnea index (AHI), and obstructive apnea index (OAI). Main Outcomes and Measures Regional electroencephalogram-derived SWA (0.5 to 4 Hz) topography and exponential decay parameters derived from frontal and posterior cortical regions. The frontal-to-posterior decay-rate ratio was evaluated as a summary measure of regional sleep homeostasis. Results In children with lower hypopnea index, SWA demonstrated the expected developmental pattern, with posterior predominance in younger children and a progressive shift toward a more balanced anterior-posterior distribution with age. Increasing HI was associated with attenuation or reversal of this spatial organization. Global SWA showed no meaningful association with SDB severity. In contrast, regional frontal and posterior decay parameters were strongly associated with HI (adjusted R2 = 0.53; p < 1e-6) but not OAI (adjusted R2 = 0.05; p = .95). The frontal-to-posterior decay-rate ratio showed the strongest association with HI {beta} = 4.15; 95% CI, 3.17-5.13; p < 1e-10; adjusted R2 = 0.55. Conclusions and Relevance Pediatric SDB was associated with regional disruption of slow-wave sleep homeostasis rather than global loss of deep sleep. These alterations affected both the spatial organization and temporal dynamics of SWA during a period of active cortical maturation and were not captured by conventional sleep metrics. Regional SWA dynamics may provide a developmentally sensitive marker of physiological disease burden in children with SDB.

Behavioral and Clinical Correlates of Poor Sleep and Anxiety Symptoms in Adults Aged 50 Years and Older: A Cross-Sectional Study

In this online convenience sample of adults aged ≥50 years, sleep quality, anxiety symptoms, and total physical activity showed consistent cross-sectional associations and require confirmation in representative longitudinal studies.

Obstructive sleep apnea severity and morning hypertension in children: Age-stratified associations across developmental stages.

Obstructive sleep apnea (OSA) is common in children and has been linked to cardiovascular dysregulation, including elevated blood pressure (BP). This study examined whether OSA severity is independently associated with morning hypertension in a pediatric clinical cohort, and whether associations vary by developmental stage and sex. We retrospectively analyzed 806 children aged 1 to 18 years (55.2% Male) who underwent overnight polysomnography (PSG) and had BP recorded before and after the PSG at the University of Louisville and Norton Pediatric Sleep Center. OSA was categorized based on the total apnea hypopnea index (AHI) and severity was categorized based on the obstructive apnea hypopnea index (OAHI) the cohort was stratified as: normal/snoring (OAHI < 1 event/hr, n = 318), mild OSA (OAHI 1-4.9 events/hr, n = 205), moderate OSA (OAHI 5-9.9 events/hr, n = 103), and severe OSA (OAHI ≥ 10 events/hr, n = 180). Evening and morning blood pressures were recorded and classified per American Academy of Pediatrics guidelines. ANOVA/ANCOVA, linear regression, and multivariable logistic regression examined associations between the total AHI and blood pressure, with adjustment for age, sex, body mass index (BMI) z-score, and comorbidities. Morning systolic blood pressure (SBP) rose from 108 ± 13 mmHg in non-OSA children to 118 ± 15 mmHg in severe OSA. Severe OSA more than doubled the odds of morning hypertension across all adjusted models (OR 2.35; 95% CI 1.57-3.52, p < 0.001). Each 1-unit increase in AHI was associated with a 0.137 mmHg rise in morning SBP after adjustment (p < 0.001). Moderate OSA's association was attenuated after BMI adjustment, while BMI z-score itself was an independent predictor of BP grade (OR 1.52; 95% CI 1.27-1.82; p < 0.001). Participants were categorized by developmental age. Subgroup analyses found the strongest association between AHI and systolic blood pressure in preschool children, while the link with diastolic blood pressure appeared only in older groups. Sex-stratified analyses showed similar AHI-blood pressure associations in both males and females, with no significant interaction. Severe OSA independently increased the risk of morning hypertension in children, regardless of obesity status, sex, or developmental stage. Routine BP monitoring is warranted across the full OSA severity spectrum.

Sleep Duration and History of Stroke Among U.S. Adults

Does Hypoxic Burden Better Explain Sex Differences in Functional Impairments Than Apnoea-Hypopnoea Index in Obstructive Sleep Apnoea?

Women with obstructive sleep apnoea (OSA) report more severe functional impairments than men, despite lower apnoea-hypopnoea index (AHI) values. This raises questions about the adequacy of AHI for capturing OSA severity. We explored sex differences in functional outcomes in OSA patients and examined whether AHI or hypoxic burden (HB) better explained these differences. We analysed cross-sectional data from Sydney Sleep Biobank (2018-2023). Adults with OSA (AHI ≥ 5 events/h on polysomnography) with data on mood (Depression, Anxiety and Stress Scale; DASS-21) and daytime functioning (Functional Outcomes of Sleep Questionnaire; FOSQ-10) were included. Linear regression models examined associations between sex, AHI, HB and functional outcomes. Interaction effects of sex and AHI/HB were explored. Among 518 untreated OSA patients (67.7% men, mean age = 54.0, SD = 14.6 years), women had significantly higher DASS-21 (15.4 vs. 12.1, p < 0.01) and lower FOSQ-10 (14.1 vs. 16.0, p < 0.0001) scores, despite lower AHI (28.7 vs. 32.9, p = 0.10) and HB (47.4 vs. 82.7, p < 0.001). Neither AHI nor HB was associated with worse mood, although AHI was linked to poorer mood in women in sensitivity analyses. AHI and HB were associated with worse FOSQ-10. In multivariable models adjusting for demographics, anthropometry, comorbidities and medications, neither AHI nor HB consistently predicted mood or daytime functioning. Sex differences in mood were explained by comorbid mood disorders, insomnia and chronic pain. Women had more severe functional impairments despite milder respiratory indices. Given the greater influence of comorbidities on functional outcomes than respiratory metrics, comprehensive comorbidity assessment in OSA evaluation is warranted, especially in females.