Multicomponent Analysis of Sleep Using Electrocortical, Respiratory, Autonomic and Hemodynamic Signals Reveals Distinct Features of Stable and Unstable NREM and REM Sleep

Association of self-reported and objective sleep disturbance with the spectrum of gastroesophageal reflux disease

STUDY OBJECTIVES

The relationship between obstructive sleep apnea (OSA) and gastroesophageal reflux disease (GERD) is complex. We aimed to determine the association of self-reported and objective sleep parameters with diverse manifestations of the GERD spectrum.

METHODS

We prospectively recruited 561 individuals who underwent an electrocardiogram-based cardiopulmonary coupling for OSA screening during a health check-up. All participants received the Reflux Disease Questionnaire and an upper endoscopy to determine the presence of troublesome reflux symptoms and erosive esophagitis (EE). Sleep quality was evaluated by the Pittsburgh Sleep Quality Index and sleep dysfunction was defined as a Pittsburgh Sleep Quality Index score > 5. OSA was defined as a cardiopulmonary coupling-derived apnea-hypopnea index exceeding 15 events/h. Comparisons were made between participants on the GERD spectrum with respect to their various self-reported and objective sleep parameters.

RESULTS

Among the 277 patients with GERD (49.4%), 198 (35.3%) had EE. Patients with GERD had higher PSQI scores (6.99 ± 3.97 vs 6.07 ± 3.73, P = .005) and a higher prevalence of sleep dysfunction (60.6% vs 49.6%, P = .009). Patients with EE had a higher prevalence of OSA (42.9% vs 33.9%, P = .034). Along the GERD spectrum, symptomatic patients with EE had the highest PSQI scores and prevalence of sleep dysfunction (70.7%), while asymptomatic patients with EE had the highest prevalence of OSA (44%).

CONCLUSIONS

Our findings indicate a high prevalence of sleep dysfunction among individuals with GERD. Furthermore, patients on the GERD spectrum are prone to experiencing a range of self-reported and objective sleep disturbances.

CITATION

Hu K-Y, Tseng P-H, Hsu W-C, et al. Association of self-reported and objective sleep disturbance with the spectrum of gastroesophageal reflux disease. J Clin Sleep Med. 2024;20(6):911-920.

Sleep quality, sleep apnea, and metabolic health in children treated with adenotonsillectomy

PURPOSE

The aim of this study was to determine if cardiopulmonary coupling (CPC) calculated sleep quality (SQI) may predict changes in metabolic health in children treated with early adenotonsillectomy (eAT) for obstructive sleep apnea (OSA).

METHODS

Secondary analysis of the Childhood Adenotonsillectomy Trial (CHAT) was performed including children 5.0-9.9 years with OSA assigned to eAT. The cohort was stratified based on SQI and AHI to evaluate (1) response to eAT in children with high sleep quality (SQI ≥ 75) and mild-OSA, AHI < 5.0 (group1) and children with moderate-OSA AHI ≥ 5.0 or SQI < 75 (group2) at baseline and (2) effect of eAT therapy on metabolic health, GroupRemission (AHI < 1.0, SQI ≥ 75) compared to GroupResidual.

RESULTS

At baseline group2 (n=124) had higher average heart rate during sleep (AHRSleep), 87 vs. 81 beats/minute (p < 0.001) compared to group1 (n=72). After surgery, group2 on average had less increase in BMI z-score 0.13 vs. 0.27, (p = 0.025), improved their SQI + 2.06 compared to decline - 3.75 in group1, (p = 0.015), decreased AHRSleep-- 2.90 vs. - 0.34 (p = 0.025) and AHI - 5.00 vs. - 0.36 (p = 0.002). GroupRemission was younger 6.59 vs. 7.41; p < 0.001; with lower BMI z-score 0.90 vs. 1.34; p = 0.021; AHRSleep 80.60 vs. 83.50; p = 0.032; fasting insulin (µIU/ml) 7.54 vs. 12.58; p = 0.017 and glucose (mmol/L) 4.45 vs. 4.60; p = 0.049, with better lipid metabolism though not statistically significantly, low-density-lipoprotein 90.26 mg/dL vs. 97.94; p = 0.081 and cholesterol 154.66 mg/dL vs. 164.36; p = 0.076.

CONCLUSION

The results may indicate that children with mild-OSA and high-SQI may be less likely to benefit from eAT than children with moderate-OSA. To improve metabolic health, successfully treating both AHI and SQI is likely needed. CPC-calculated SQI may have a role to identify children less likely to benefit from eAT and to evaluate success of therapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00560859.

Sleep medicine: Practice, challenges and new frontiers

Sleep medicine is an ambitious cross-disciplinary challenge, requiring the mutual integration between complementary specialists in order to build a solid framework. Although knowledge in the sleep field is growing impressively thanks to technical and brain imaging support and through detailed clinic-epidemiologic observations, several topics are still dominated by outdated paradigms. In this review we explore the main novelties and gaps in the field of sleep medicine, assess the commonest sleep disturbances, provide advices for routine clinical practice and offer alternative insights and perspectives on the future of sleep research.

Cardiopulmonary Coupling

Cardiopulmonary coupling (CPC) is a technique that generates sleep spectrogram by calculating the cross-spectral power and coherence of heart rate variability and respiratory tidal volume fluctuations. There are several forms of CPC in the sleep spectrogram, which may provide information about normal sleep physiology and pathological sleep states. Since CPC can be calculated from any signal recording containing heart rate and respiration information, such as photoplethysmography (PPG) or blood pressure, it can be widely used in various applications, including wearables and non-contact devices. When derived from PPG, an automatic apnea-hypopnea index can be calculated from CPC-oximetry as PPG can be obtained from oximetry alone. CPC-based sleep profiling reveals the effects of stable and unstable sleep on sleep apnea, insomnia, cardiovascular regulation, and metabolic disorders. Here, we introduce, with examples, the current knowledge and understanding of the CPC technique, especially the physiological basis, analytical methods, and its clinical applications.

Cardiopulmonary Sleep Spectrograms Open a Novel Window Into Sleep Biology-Implications for Health and Disease

The interactions of heart rate variability and respiratory rate and tidal volume fluctuations provide key information about normal and abnormal sleep. A set of metrics can be computed by analysis of coupling and coherence of these signals, cardiopulmonary coupling (CPC). There are several forms of CPC, which may provide information about normal sleep physiology, and pathological sleep states ranging from insomnia to sleep apnea and hypertension. As CPC may be computed from reduced or limited signals such as the electrocardiogram or photoplethysmogram (PPG) vs. full polysomnography, wide application including in wearable and non-contact devices is possible. When computed from PPG, which may be acquired from oximetry alone, an automated apnea hypopnea index derived from CPC-oximetry can be calculated. Sleep profiling using CPC demonstrates the impact of stable and unstable sleep on insomnia (exaggerated variability), hypertension (unstable sleep as risk factor), improved glucose handling (associated with stable sleep), drug effects (benzodiazepines increase sleep stability), sleep apnea phenotypes (obstructive vs. central sleep apnea), sleep fragmentations due to psychiatric disorders (increased unstable sleep in depression).

Characteristics of Children Likely to Have Spontaneous Resolution of Obstructive Sleep Apnea: Results from the Childhood Adenotonsillectomy Trial (CHAT)

OBJECTIVE

To evaluate if cardiopulmonary coupling (CPC) calculated sleep quality (SQI) may have a role in identifying children that may benefit from other intervention than early adenotonsillectomy (eAT) in management of obstructive sleep apnea (OSA).

METHODS

A secondary analysis of electrocardiogram-signals (ECG) and oxygen saturation-data (SpO₂) collected during polysomnography-studies in the prospective multicenter Childhood Adenotonsillectomy Trial (CHAT) to calculate CPC-SQI and apnea hypopnea index (AHI) was executed. In the CHAT, children 5-9 years with OSA without prolonged oxyhemoglobin desaturations were randomly assigned to adenotonsillectomy (eAT) or watchful waiting with supportive care (WWSC). The primary outcomes were to document change in attention and executive function evaluated with the Developmental Neuropsychological Assessment (NEPSY). In our analysis, children in the WWSC-group with spontaneous resolution of OSA (AHI_Obstructive < 1.0) and high-sleep quality (SQI ≥ 75) after 7-months were compared with children that showed residual OSA.

RESULTS

Of the 227 children randomized to WWSC, 203 children had available data at both baseline and 7-month follow-up. The group that showed resolution of OSA at month 7 (n = 43, 21%) were significantly more likely to have high baseline SQI 79.96 [CI_95% 75.05, 84.86] vs. 72.44 [CI_95% 69.50, 75.39], p = 0.005, mild OSA AHI_Obstructive 4.01 [CI_95% 2.34, 5.68] vs. 6.52 [CI_95% 5.47, 7.57], p= 0.005, higher NEPSY-attention-executive function score 106.22 [CI_95% 101.67, 110.77] vs. 101.14 [CI_95% 98.58, 103.72], p = 0.038 and better quality of life according to parents 83.74 [CI_95% 78.95, 88.54] vs. 77.51 [74.49, 80.53], p = 0.015. The groups did not differ when clinically evaluated by Mallampati score, Friedman palate position or sleep related questionnaires.

CONCLUSIONS

Children that showed resolution of OSA were more likely to have high-SQI and mild OSA, be healthy-weight and have better attention and executive function and quality of life at baseline. As this simple method to evaluate sleep quality and OSA is based on analyzing signals that are simple to collect, the method is practical for sleep-testing, over multiple nights and on multiple occasions. This method may assist physicians and parents to determine the most appropriate therapy for their child as some children may benefit from WWSC rather than interventions. If the parameters can be used to plan care a priori, this would provide a fundamental shift in how childhood OSA is diagnosed and managed.

Digital sleep measures and white matter health in the Framingham Heart Study

AIM

Impaired sleep quality and sleep oxygenation are common sleep pathologies. This study assessed the impact of these abnormalities on white matter (WM) integrity in an epidemiological cohort.

METHODS

The target population was the Framingham Heart Study Generation-2/Omni-1 Cohorts. Magnetic resonance imaging (diffusion tensor imaging) was used to assess WM integrity. Wearable digital devices were used to assess sleep quality: the (M1-SleepImage™ system) and the Nonin WristOx for nocturnal oxygenation. The M1 device collects trunk actigraphy and the electrocardiogram (ECG); sleep stability indices were computed using cardiopulmonary coupling using the ECG. Two nights of recording were averaged.

RESULTS

Stable sleep was positively associated with WM health. Actigraphic periods of wake during the sleep period were associated with increased mean diffusivity. One marker of sleep fragmentation which covaries with respiratory chemoreflex activation was associated with reduced fractional anisotropy and increased mean diffusivity. Both oxygen desaturation index and oxygen saturation time under 90% were associated with pathological directions of diffusion tensor imaging signals. Gender differences were noted across most variables, with female sex showing the larger and significant impact.

CONCLUSIONS

Sleep quality assessed by a novel digital analysis and sleep hypoxia was associated with WM injury, especially in women.