All Obstructive Sleep Apnea Events Are Not Created Equal: The Relationship between Event-related Hypoxemia and Physiologic Response.

Rationale: Obstructive sleep apnea (OSA) severity is typically assessed by the apnea-hypopnea index (AHI), a frequency-based metric that allocates equal weight to all respiratory events. However, more severe events may have a greater physiologic impact. Objectives: The purpose of this study was to determine whether the degree of event-related hypoxemia would be associated with the postevent physiologic response. Methods: Patients with OSA (AHI, ⩾5/h) from the multicenter Canadian Sleep and Circadian Network cohort were studied. Using mixed-effect linear regression, we examined associations between event-related hypoxic burden (HBev) assessed by the area under the event-related oxygen saturation recording with heart rate changes (ΔHRev), vasoconstriction (vasoconstriction burden [VCBev] assessed with photoplethysmography), and electroencephalographic responses (power ratio before and after events). Results: Polysomnographic recordings from 658 patients (median [interquartile range] age, 55.00 [45.00, 64.00] yr; AHI, 27.15 [14.90, 64.05] events/h; 42% female) were included in the analyses. HBev was associated with an increase in all physiologic responses after controlling for age, sex, body mass index, sleep stage, total sleep time, and study centers; for example, 1 standard deviation increase in HBev was associated with 0.21 [95% confidence interval, 0.2, 0.22], 0.08 [0.08, 0.09], and 0.22 [0.21, 0.23] standard deviation increases in ΔHRev, VCBev, and ß-power ratio, respectively. Conclusions: Increased event-related hypoxic burden was associated with greater responses across a broad range of physiologic signals. Future metrics that incorporate information about the variability of these physiologic responses may have promise in providing a more nuanced assessment of OSA severity.

Contribution of obstructive sleep apnea to disrupted sleep in a large clinical cohort of patients with suspected obstructive sleep apnea.

STUDY OBJECTIVES: The response of sleep depth to CPAP in patients with OSA is unpredictable. The odds-ratio-product (ORP) is a continuous index of sleep depth and wake propensity that distinguishes different sleep depths within sleep stages, and different levels of vigilance during stage wake. When expressed as fractions of time spent in different ORP deciles, nine distinctive patterns are found. Only three of these are associated with OSA. We sought to determine whether sleep depth improves on CPAP exclusively in patients with these three ORP patterns. METHODS: ORP was measured during the diagnostic and therapeutic components of 576 split-night polysomnographic (PSG) studies. ORP architecture in the diagnostic section was classified into one of the nine possible ORP patterns and the changes in sleep architecture were determined on CPAP for each of these patterns. ORP architecture was similarly determined in the first half of 760 full-night diagnostic PSG studies and the changes in the second half were measured to control for differences in sleep architecture between the early and late portions of sleep time in the absence of CPAP. RESULTS: Frequency of the three ORP patterns increased progressively with the apnea-hypopnea index. Sleep depth improved significantly on CPAP only in the three ORP patterns associated with OSA. Changes in CPAP in the other six patterns, or in full diagnostic PSG studies, were insignificant or paradoxical. CONCLUSIONS: ORP architecture types can identify patients in whom OSA adversely affects sleep and whose sleep is expected to improve on CPAP therapy.

Differences in Predicted Therapeutic Outcome of Mandibular Advancement Determined by Remotely Controlled Mandibular Positioner in Canadian and Chinese Apneic Patients.

Background: In-lab mandibular protrusive titration using a remotely controlled mandibular positioner (RCMP) could predict the success rate of mandibular advancement device (MAD) and reliably determine the Optimal Protrusive Position (OPP) for obstructive sleep apnea (OSA) patients. The aim of this study was to compare MAD success rate using in-lab RCMP manual titration performed in Caucasian and Chinese OSA patients. Methods: Manual RCMP titration was performed during an in-lab sleep study using the same procedure that had been previously reported in untreated Caucasian and Chinese OSA patients. Success rate was determined according to classical success criteria or to those previously used for RCMP titration. Results: A total of 160 subjects were included in this study, and conclusive data were obtained from 141 (71 Chinese and 70 Caucasian OSA patients). Chinese patients were significantly younger, with lower BMI and more severe OSA disease than the Canadian counterparts. Among patients with predicted success, the OPP expressed in % of full protrusion position did not differ between the two ethnic groups. Chinese ethnicity, younger age and lower baseline AHI were significant determinants of RCMP success. In a multivariate analysis, only ethnicity and AHI were found to significantly account for success, the odds ratio for success in Chinese compared to Caucasians corrected for AHI being 3.7 and 4.6 depending on criteria used to define success. Conclusion: Although the OSA disease was more severe in Chinese patients, the predicted success rate of MAD according to RCMP titration was higher in Chinese than in Caucasians. This study was registered on ClinicalTrials.gov (NCT03231254).

Obstructive sleep apnea and its management in patients with atrial fibrillation: An International Collaboration of Sleep Apnea Cardiovascular Trialists (INCOSACT) global survey of practicing cardiologists.

Background: Among international cardiologists it is unclear whether equipoise exists regarding the benefit of diagnosing and managing obstructive sleep apnea (OSA) to improve atrial fibrillation (AF) outcomes and whether clinical practice and equipoise are linked. Methods: Between January 2019 and June 2020 we distributed a web-based 12-question survey regarding OSA and AF management to practicing cardiologists in 16 countries. Results: The United States, Japan, Sweden, and Turkey accounted for two-thirds of responses. 863 cardiologists responded; half were general cardiologists, a quarter electrophysiologists. Responses regarding treating OSA with CPAP to improve AF endpoints were mixed. 33% of respondents referred AF patients for OSA screening. OSA was diagnosed in 48% of referred patients and continuous positive airway pressure (CPAP) was prescribed for 59% of them. Nearly 70% of respondents believed randomized controlled trials (RCTs) of OSA treatment in AF patients were necessary and indicated willingness to contribute to such trials. Conclusions: There was no clinical equipoise among surveyed cardiologists; a majority expressed certainty that combined OSA and AF treatment is superior to AF treatment alone for improving AF outcomes. However, a minority of surveyed cardiologists referred AF patients for OSA testing, and while half of screened AF patients had OSA, CPAP was prescribed in little more than half of them, reflecting the view that better clinical trial evidence is needed to support this practice. Our results underscore the need for larger, multi-national prospective studies of OSA treatment and AF outcomes to inform more uniform society guideline recommendations.

Association of insomnia and short sleep duration, alone or with comorbid obstructive sleep apnea, and the risk of chronic kidney disease.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA), sleep fragmentation, and short sleep duration (SD) have been associated with chronic kidney disease (CKD). However, these potential mechanisms for CKD have not been compared in the same cohort. This study investigated the independent and combined impact of OSA and insomnia with short sleep duration on the risk of CKD progression in a sleep clinic population. METHODS: In a cross-sectional study design, adults with suspected OSA completed an overnight sleep study and a questionnaire that included the Insomnia Severity Index (ISI) and Pittsburgh Sleep Quality Index (PSQI). They also provided blood and urine samples for measurement of the glomerular filtration rate and urine albumin:creatinine ratio, from which the risk of CKD progression was determined. RESULTS: Participants (n = 732, 41% female, 55 ± 13 years) were categorized into four groups: no/mild OSA without insomnia (NM-OSA, n = 203), insomnia with SD without OSA (Insomnia-SD, n = 104), moderate-to-severe OSA without insomnia (MS-OSA, n = 242), and comorbid insomnia and OSA with SD (COMISA-SD, n = 183). After stratification, 12.8% of NM-OSA, 15.4% of Insomnia-SD, 28.9% of MS-OSA, and 31.7% of the COMISA-SD participants had an increased risk of CKD progression. Compared to NM-OSA, the odds ratio (OR) for an increased risk of CKD progression was not increased in Insomnia-SD (OR 0.95, confidence interval [CI]: 0.45-1.99) and was increased to the same degree in MS-OSA (OR 2.79, CI: 1.60-4.85) and COMISA-SD (OR 3.04, CI: 1.69-5.47). However, the ORs were similar between the MS-OSA and COMISA-SD groups across all statistical models (p ≥ .883). CONCLUSIONS: In a sleep clinic population, insomnia with short sleep duration does not increase the risk of CKD progression; nor does it further increase the risk of CKD progression associated with moderate-to-severe OSA.

Diagnosis and management of sleep apnea by a clinical nurse: a noninferiority randomized clinical trial.

STUDY OBJECTIVES: References for the evaluation of obstructive sleep apnea often exceed the sleep clinic's capacity. We aimed to assess the noninferiority of a nurse-communicated model compared with a traditional physician-led model for the initial management of uncomplicated obstructive sleep apnea in the sleep clinic. METHODS: In this noninferiority, open-label randomized controlled trial, patients referred for the evaluation of uncomplicated obstructive sleep apnea (home sleep apnea test with respiratory event index ≥ 20 events/h) were randomized to a nurse-communicated or a physician-led management. The primary endpoint was noninferiority in the mean change from baseline of the Epworth Sleepiness Scale score at 3 and 6 months, assuming a noninferiority margin of -2.0 points. Secondary outcomes included quality of life (Quebec Sleep Questionnaire) and positive airway pressure adherence. RESULTS: Two hundred participants were randomized to a nurse-communicated (n = 101) or physician-led management (n = 99). Overall, 48 participants were lost at follow-up (27.7% and 20.4% in the nurse-communicated and physician-led groups, respectively). Most participants were treated with positive airway pressure (78.2% and 80.6% in the nurse-communicated and physician-led management groups, respectively). There was substantial missing data for the Epworth Sleepiness Scale (33% and 58% at 3 and 6 months in the nurse-communicated group and 29% and 55% in the physician-led group) and Quebec Sleep Questionnaire (86% and 91% at 3 and 6 months and 79.6% and 85.7% in the physician-led group). The difference in mean change between groups for the Epworth Sleepiness Scale was -0.71 (95% confidence interval -2.25 to 0.83) at 3 months and -0.21 (95% confidence interval -1.85 to 1.45) at 6 months. For each domain of the Quebec Sleep Questionnaire at 3 and 6 months, the lower bound of the 95% confidence interval was greater than the prespecified noninferiority margin. Positive airway pressure adherence was similar between groups. CONCLUSIONS: Among patients with uncomplicated obstructive sleep apnea, nurse-communicated management was noninferior to physician-led management in terms of sleepiness, quality of life, and positive airway pressure adherence at 6 months. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Management of Sleep Apnea Patients by a Clinical Nurse (Supernurse), URL: https://clinicaltrials.gov/ct2/show/NCT03455920; Identifier: NCT03455920. CITATION: Lajoie AC, Privé A, Roy-Hallé A, Pagé D, Simard S, Séries F. Diagnosis and management of sleep apnea by a clinical nurse: a noninferiority randomized clinical trial. J Clin Sleep Med. 2022;18(1):89-97.

Risk of chronic kidney disease in patients with obstructive sleep apnea.

STUDY OBJECTIVES: Chronic kidney disease (CKD) is a global health concern and a major risk factor for cardiovascular morbidity and mortality. Obstructive sleep apnea (OSA) may exacerbate this risk by contributing to the development of CKD. This study investigated the prevalence and patient awareness of the risk of CKD progression in individuals with OSA. METHODS: Adults referred to five Canadian academic sleep centers for suspected OSA completed a questionnaire, a home sleep apnea test or in-lab polysomnography and provided blood and urine samples for measurement of estimated glomerular filtration rate (eGFR) and the albumin:creatinine ratio (ACR), respectively. The risk of CKD progression was estimated from a heat map incorporating both eGFR and ACR. RESULTS: 1295 adults (42% female, 54 ± 13 years) were categorized based on the oxygen desaturation index (4% desaturation): <15 (no/mild OSA, n = 552), 15-30 (moderate OSA, n = 322), and >30 (severe OSA, n = 421). After stratification, 13.6% of the no/mild OSA group, 28.9% of the moderate OSA group, and 30.9% of the severe OSA group had a moderate-to-very high risk of CKD progression (p < .001), which was defined as an eGFR <60 mL/min/1.73 m2, an ACR ≥3 mg/mmol, or both. Compared to those with no/mild OSA, the odds ratio for moderate-to-very high risk of CKD progression was 2.63 (95% CI: 1.79-3.85) for moderate OSA and 2.96 (2.04-4.30) for severe OSA after adjustment for CKD risk factors. Among patients at increased risk of CKD progression, 73% were unaware they had abnormal kidney function. CONCLUSION: Patients with moderate and severe OSA have an increased risk of CKD progression independent of other CKD risk factors; most patients are unaware of this increased risk.

Oximetry neither to prescribe long-term oxygen therapy nor to screen for severe hypoxaemia.

BACKGROUND AND OBJECTIVE: Transcutaneous pulse oximetry saturation (S pO2 ) is widely used to diagnose severe hypoxaemia and to prescribe long-term oxygen therapy (LTOT) in COPD. This practice is not based on evidence. The primary objective of this study was to determine the accuracy (false positive and false negative rates) of oximetry for prescribing LTOT or for screening for severe hypoxaemia in patients with COPD. METHODS: In a cross-sectional study, we correlated arterial oxygen saturation (S aO2 ) and S pO2 in patients with COPD and moderate hypoxaemia (n=240) and calculated the false positive and false negative rates of S aO2 at the threshold of ≤88% to identify severe hypoxaemia (arterial oxygen tension (P aO2 ) ≤55 mmHg or P aO2 <60 mmHg) in 452 patients with COPD with moderate or severe hypoxaemia. RESULTS: The correlation between S aO2 and S pO2 was only moderate (intra-class coefficient of correlation: 0.43; 95% confidence interval: 0.32-0.53). LTOT would be denied in 40% of truly hypoxaemic patients on the basis of a S aO2 >88% (i.e., false negative result). Conversely, LTOT would be prescribed on the basis of a S aO2 ≤88% in 2% of patients who would not qualify for LTOT (i.e., false positive result). Using a screening threshold of ≤92%, 5% of severely hypoxaemic patients would not be referred for further evaluation. CONCLUSIONS: Several patients who qualify for LTOT would be denied treatment using a prescription threshold of saturation ≤88% or a screening threshold of ≤92%. Prescription of LTOT should be based on P aO2 measurement.

Stress and Loss of Ovarian Function: Novel Insights into the Origins of Sex-Based Differences in the Manifestations of Respiratory Control Disorders During Sleep.

The respiratory system of women and men develops and functions in distinct neuroendocrine milieus. Despite differences in anatomy and neural control, homeostasis of arterial blood gases is ensured in healthy individuals regardless of sex. This convergence in function differs from the sex-based differences observed in many respiratory diseases. Sleep-disordered breathing (SDB) results mainly from episodes of upper airway closure. This complex and multifactorial respiratory disorder shows significant sexual dimorphism in its clinical manifestations and comorbidities. Guided by recent progress from basic research, this review discusses the hypothesis that stress is necessary to reveal the sexual dimorphism of SDB.

Impact of continuous positive airway pressure mode on adherence to treatment in obstructive sleep apnea patients awaiting bariatric surgery.

Obstructive sleep apnea is prevalent in the bariatric population, and is associated with various complications. Despite increasing popularity, automatic positive airway pressure has not yet been studied in this population. The objective was to compare treatment adherence between automatic positive airway pressure and fixed positive airway pressure (continuous positive airway pressure) in obstructive sleep apnea patients awaiting bariatric surgery. This randomized controlled trial involved obese patients newly diagnosed with severe obstructive sleep apnea and awaiting bariatric surgery. The primary outcome was the difference in adherence between automatic positive airway pressure and continuous positive airway pressure pre-operatively. Secondary outcomes included positive airway pressure efficacy, adherence at 1 month, adverse effects, quality of life and peri-operative complications. Analyses were conducted using a modified intention-to-treat methodology. Fifty patients were randomized. Baseline characteristics and duration of positive airway pressure therapy were comparable between groups. At the time of surgery, the percentage of overall nights positive airway pressure used was 96.9% [95% confidence interval: 93.5-100] and 86.0% [95% confidence interval: 66.9-100] in the automatic positive airway pressure and continuous positive airway pressure groups, respectively (p = .047). Average use was 6.3 hr per night [95% confidence interval: 5.1-7.2] and 5.9 hr per night [95% confidence interval: 3.0-8.8], with a difference of 0.4 hr favouring automatic positive airway pressure (p = .75). Nightly use ≥ 4 hr per night was 86.4% and 74.0% in the automatic positive airway pressure and fixed continuous positive airway pressure groups, respectively (p = .22). There were no statistically significant differences regarding adherence at 1 month, efficacy parameters, adverse effects, quality of life and peri-operative complications. With no difference on the safety profile and efficiency parameters, treatment adherence is not improved with automatic positive airway pressure compared with fixed continuous positive airway pressure in obstructive sleep apnea patients awaiting bariatric surgery.

CPAP Is Not Needed in Every Sleep Apnea Patient Awaiting Bariatric Surgery.

BACKGROUND: Obstructive sleep apnea (OSA) patients are at high risk of postoperative complications following bariatric surgery. The aim of our study was to compare peri- and postoperative outcomes in OSA patients awaiting laparoscopic bariatric surgery who were prescribed CPAP treatment or not before surgery using nocturnal home oximetry and capillary blood gas measurements. METHODS: Data on 1094 eligible patients were analyzed. In accordance with our algorithm, those with ODI < 25/h and pCO2 < 45 mmHg (358 mild/moderate apnea and 447 non-apneic) underwent surgery without previous treatment, whereas those with an ODI ≥ 25/h (n = 289) were prescribed CPAP. We compared peri- and postoperative outcomes in treated and untreated patients. RESULTS: Treated patients were significantly older with a higher body mass index and a higher percentage of men than non-apneic and untreated OSA. Hypertension and diabetes were significantly more prevalent in the treated and untreated OSA patients than in the non-apneic. Regarding the occurrence of cardiopulmonary complications, the incidence of cardiac arrhythmia was higher in the treated patients than in the non-apneic and the untreated OSA (2.4%; 0.6 and 0.5%, p = 0.03). The slightly longer length of hospital stay seen in treated patients compared to those of other groups (2.8 ± 1.7; 2.6 ± 2.1 and 2.6 ± 1.8 days, p = 0.03) was no longer observed after adjusting for age and BMI. CONCLUSIONS: There is no risk increase for complications following bariatric surgery in untreated patients presenting mild/moderate OSA identified by a noninvasive screening algorithm.

Randomized Trial of Nocturnal Oxygen in Chronic Obstructive Pulmonary Disease.

BACKGROUND: Long-term oxygen therapy improves survival in patients with chronic obstructive pulmonary disease (COPD) and chronic severe daytime hypoxemia. However, the efficacy of oxygen therapy for the management of isolated nocturnal hypoxemia is uncertain. METHODS: We designed this double-blind, placebo-controlled, randomized trial to determine, in patients with COPD who have nocturnal arterial oxygen desaturation without qualifying for long-term oxygen therapy, whether nocturnal oxygen provided for a period of 3 to 4 years would decrease mortality or the worsening of disease such that patients meet current specifications for long-term oxygen therapy. Patients with an oxygen saturation of less than 90% for at least 30% of the recording time on nocturnal oximetry were assigned, in a 1:1 ratio, to receive either nocturnal oxygen or ambient air from a sham concentrator (placebo). The primary outcome was a composite of death from any cause or a requirement for long-term oxygen therapy as defined by the Nocturnal Oxygen Therapy Trial (NOTT) criteria in the intention-to-treat population. RESULTS: Recruitment was stopped prematurely because of recruitment and retention difficulties after 243 patients, of a projected 600, had undergone randomization at 28 centers. At 3 years of follow-up, 39.0% of the patients assigned to nocturnal oxygen (48 of 123) and 42.0% of those assigned to placebo (50 of 119) met the NOTT-defined criteria for long-term oxygen therapy or had died (difference, -3.0 percentage points; 95% confidence interval, -15.1 to 9.1). CONCLUSIONS: Our underpowered trial provides no indication that nocturnal oxygen has a positive or negative effect on survival or progression to long-term oxygen therapy in patients with COPD. (Funded by the Canadian Institutes of Health Research; INOX ClinicalTrials.gov number, NCT01044628.).

Reliability of Home Nocturnal Oximetry in the Diagnosis of Overlap Syndrome in COPD.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) and sleep apnea are common conditions and often coexist. The proper diagnosis of sleep apnea may affect the management and outcome of patients with COPD. OBJECTIVE: To determine the accuracy of home nocturnal oximetry to distinguish between nocturnal oxygen desaturation related to COPD alone or to sleep apnea in patients with moderate-to-severe COPD who have significant nocturnal hypoxemia with cyclical changes in saturation. METHODS: This study involved a comparison of home nocturnal oximetry and laboratory-based polysomnography (PSG) in patients with moderate-to-severe COPD considered for inclusion in a trial of nocturnal oxygen therapy. All of the patients had significant nocturnal oxygen desaturation (defined as ≥30% of the recording time with a transcutaneous arterial oxygen saturation <90%) with cyclical changes in saturation suggestive of sleep apnea. RESULTS: PSG was obtained in 90 patients; 45 patients (mean age = 68 years, SD = 8; 71% men; mean forced expiratory volume in 1 s [FEV1] = 50.6% predicted value, SD = 18.6%; data from 41 patients) fulfilled the criteria for sleep apnea (mean apnea-hypopnea index = 32.6 events/h, SD = 19.9) and 45 patients (mean age = 69 years, SD = 8; 87% men; mean FEV1 predicted value 44.6%, SD = 15%) did not (mean apnea-hypopnea index = 5.5 events/h, SD = 3.8). None of the patients' characteristics (including demographic, anthropometric, and physiologic measures) predicted the diagnosis of sleep apnea according to PSG results. CONCLUSION: The diagnosis of sleep apnea in patients with moderate to severe COPD cannot rely on nocturnal oximetry alone, even when typical cyclical changes in saturation are seen on oximetry tracing. When suspecting an overlap syndrome, a full-night, in-laboratory PSG should be obtained.

ERS statement on respiratory muscle testing at rest and during exercise.

Assessing respiratory mechanics and muscle function is critical for both clinical practice and research purposes. Several methodological developments over the past two decades have enhanced our understanding of respiratory muscle function and responses to interventions across the spectrum of health and disease. They are especially useful in diagnosing, phenotyping and assessing treatment efficacy in patients with respiratory symptoms and neuromuscular diseases. Considerable research has been undertaken over the past 17 years, since the publication of the previous American Thoracic Society (ATS)/European Respiratory Society (ERS) statement on respiratory muscle testing in 2002. Key advances have been made in the field of mechanics of breathing, respiratory muscle neurophysiology (electromyography, electroencephalography and transcranial magnetic stimulation) and on respiratory muscle imaging (ultrasound, optoelectronic plethysmography and structured light plethysmography). Accordingly, this ERS task force reviewed the field of respiratory muscle testing in health and disease, with particular reference to data obtained since the previous ATS/ERS statement. It summarises the most recent scientific and methodological developments regarding respiratory mechanics and respiratory muscle assessment by addressing the validity, precision, reproducibility, prognostic value and responsiveness to interventions of various methods. A particular emphasis is placed on assessment during exercise, which is a useful condition to stress the respiratory system.

Adherence to CPAP with a nasal mask combined with mandibular advancement device versus an oronasal mask: a randomized crossover trial.

PURPOSE: Evidence for the management of CPAP-treated obstructive sleep apnea suggests that oronasal masks reduce mouth leaks at the expense of higher pressures and poorer adherence. Some authors have proposed the use of mandibular advancement devices in combination with nasal masks to address this. The aim of this study was to assess adherence to CPAP after 1 month's use of a nasal mask with a mandibular advancement device and to compare adherence with an oronasal mask. METHODS: A randomized crossover trial design to assess whether a mandibular advancement device combined with a nasal mask would improve CPAP adherence compared to an oronasal mask. RESULTS: There was no improvement in CPAP adherence and self-reported interface-related pain was significantly higher with the combined treatment. CONCLUSIONS: Although the combined treatment reduced pressures, likely by improving upper airway patency, it may only be appropriate for a small number of patients due to associated discomfort. TRIAL REGISTRATION: NCT01889472.

Body Weight Status and Sleep Disturbances During Pregnancy: Does Adherence to Gestational Weight Gain Guidelines Matter?

BACKGROUND: To determine the effect of preconception body mass index (BMI) and/or gestational weight gain (GWG) on the occurrence of sleep disorders over the whole pregnancy. METHODS: A sample of 2,366 pregnant women, recruited in their 1st trimester (TM), was evaluated until delivery for their sleeping characteristics, using the Pittsburgh Sleep Quality Index (PSQI). Mixed or multinomial logistic modeling was applied, as appropriate. RESULTS: When compared with TM 1, PSQI score was the lowest at TM 2 (ß = -1.03; 95% CI: -1.17 to -0.89) and highest in TM 3 (ß = 0.27; 95% CI: 0.10-0.45). Obese (ß = 0.48; 95% CI: 0.17-0.78) and overweight women (ß = 0.24; 95% CI: 0.00-0.48) exhibited an overall greater PSQI than normal-weight women over the whole pregnancy. When sociodemographic factors were accounted for, the effect size was reduced by 25% among obese women (ß = 0.36; 95% CI: 0.06-0.68), but was no more not significant in overweight women (ß = 0.06; 95% CI: -0.17 to 0.30). Both obese and overweight women still exhibited, although at a lower extend, a greater PSQI than normal-weight women. Further adjustment for GWG had no effect on these observations. Obese women almost had a four-fold increased risk (OR = 3.89; 95% CI: 2.50-6.06) of being snorers in the three TMs. While GWG had only a minor effect (aOR = 3.83; 95% CI: 2.43-6.03), sociodemographic factors increased the odds of being habitual snorer (aOR = 4.04; 95% CI: 2.57-6.35). CONCLUSIONS: High prepregnancy BMI together with sociodemographic correlates appear as the most critical for sleep disturbances across pregnancy. GWG is of marginal importance, especially regarding snoring. These findings confirm the importance of considering the initial body weight status of women in tailoring sleep hygiene advises irrespective of the recommendations for weight gain during pregnancy. The results also underscore the need to providing as early as possible during a pregnancy, supportive tools to ethnic minorities, multiparous, and women from deprived socioeconomic neighborhoods.

Ventilatory support or respiratory muscle training as adjuncts to exercise in obese CPAP-treated patients with obstructive sleep apnoea: a randomised controlled trial.

BACKGROUND: Obstructive sleep apnoea (OSA) and obesity are interdependent chronic diseases sharing reduced exercise tolerance and high cardiovascular risk. INTERVENTION: A 3-month intervention with innovative training modalities would further improve functional capacity and cardiovascular health than usual cycle exercise training in already continuous positive airway pressure (CPAP)-treated obese patients with OSA. METHODS: Fifty three patients (35

Distinct Patterns of Hyperpnea During Cheyne-Stokes Respiration: Implication for Cardiac Function in Patients With Heart Failure.

STUDY OBJECTIVES: In heart failure (HF), we observed two patterns of hyperpnea during Cheyne-Stokes respiration with central sleep apnea (CSR-CSA): a positive pattern where end-expiratory lung volume remains at or above functional residual capacity, and a negative pattern where it falls below functional residual capacity. We hypothesized the negative pattern is associated with worse HF. METHODS: Patients with HF underwent polysomnography. During CSR-CSA, hyperpnea, apnea-hyperpnea cycle, and lung to finger circulation times (LFCT) were measured. Plasma N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentration and left ventricular ejection fraction (LVEF) were assessed. RESULTS: Of 33 patients with CSR-CSA (31 men, mean age 68 years), 9 had a negative hyperpnea pattern. There was no difference in age, body mass index, and apnea-hypopnea index between groups. Patients with a negative pattern had longer hyperpnea time (39.5 ± 6.4 versus 25.8 ± 5.9 seconds, P < .01), longer cycle time (67.8 ± 15.9 versus 51.7 ± 9.9 seconds, P < .01), higher NT-proBNP concentrations (2740 [6769] versus 570 [864] pg/ml, P = .01), and worse New York Heart Association class (P = .02) than those with a positive pattern. LFCT and LVEF did not differ between groups. CONCLUSIONS: Patients with HF and a negative CSR-CSA pattern have evidence of worse cardiac function than those with a positive pattern. Greater positive expiratory pressure during hyperpnea is likely generated during the negative pattern and might support stroke volume in patients with worse cardiac function. COMMENTARY: A commentary on this article appears in this issue on page 1227. CLINICAL TRIAL REGISTRATION: The trial is registered with Current Controlled Trials (www.controlled-trials.com; ISRCTN67500535) and Clinical Trials (www.clinicaltrials.gov; NCT01128816).