A narrative review of periodic breathing during sleep at high altitude: From acclimatizing lowlanders to adapted highlanders.

Periodic breathing during sleep at high altitude is almost universal among sojourners. Here, in the context of acclimatization and adaptation, we provide a contemporary review on periodic breathing at high altitude, and explore whether this is an adaptive or maladaptive process. The mechanism(s), prevalence and role of periodic breathing in acclimatized lowlanders at high altitude are contrasted with the available data from adapted indigenous populations (e.g. Andean and Tibetan highlanders). It is concluded that (1) periodic breathing persists with acclimatization in lowlanders and the severity is proportional to sleeping altitude; (2) periodic breathing does not seem to coalesce with poor sleep quality such that, with acclimatization, there appears to be a lengthening of cycle length and minimal impact on the average sleeping oxygen saturation; and (3) high altitude adapted highlanders appear to demonstrate a blunting of periodic breathing, compared to lowlanders, comprising a feature that withstands the negative influences of chronic mountain sickness. These observations indicate that periodic breathing persists with high altitude acclimatization with no obvious negative consequences; however, periodic breathing is attenuated with high altitude adaptation and therefore potentially reflects an adaptive trait to this environment.

Biological sex-related differences in the postprandial triglyceride response to intermittent hypoxaemia in young adults: a randomized crossover trial.

Obstructive sleep apnoea is characterized by chronic intermittent hypoxaemia and is independently associated with an increased risk of metabolic comorbidities (e.g. type II diabetes and ischaemic heart disease). These comorbidities could be attributable to hypoxaemia-induced alterations in blood lipid profiles. However, it remains unclear whether intermittent hypoxaemia alters triglyceridaemia differently between biological sexes. Therefore, we used a randomized crossover design to examine whether 6 h of moderate intermittent hypoxaemia (15 hypoxaemic cycles/h, 85% oxyhaemoglobin saturation) alters plasma triglyceride levels differently between men and women after a high-fat meal. Relative to men, women displayed lower levels of total triglycerides, in addition to denser triglyceride-rich lipoprotein triglycerides (TRL-TG; mainly very low-density lipoprotein triglycerides and chylomicron remnant triglycerides) and buoyant TRL-TG (mainly chylomicron triglycerides) during normoxia (ambient air) and intermittent hypoxaemia (sex × time: all P ≤ 0.008). Intermittent hypoxaemia led to higher triglyceride levels (condition: all P ≤ 0.016); however, this effect was observed only in men (sex × condition: all P ≤ 0.002). Compared with normoxia, glucose levels were higher in men and lower in women during intermittent hypoxaemia (sex × condition: P < 0.001). The different postprandial responses between biological sexes occurred despite similar reductions in mean oxyhaemoglobin saturation and similar elevations in insulin levels, non-esterified fatty acid levels and mean heart rate (sex × condition: all P ≥ 0.185). These results support growing evidence showing that intermittent hypoxaemia impacts men and women differently, and they might help to explain biological sex-related discrepancies in the rate of certain comorbidities associated with intermittent hypoxaemia. KEY POINTS: Intermittent hypoxaemia is a key characteristic of obstructive sleep apnoea and alters lipid metabolism in multiple tissues, resulting in increased circulating triglyceride levels, an important risk factor for cardiometabolic diseases. Circulating triglyceride levels are regulated differently between biological sexes, with women typically displaying much lower fasting and postprandial triglyceride levels than men, partly explaining why women of all ages experience lower mortality rates from cardiometabolic diseases. In this study, healthy young men and women consumed a high-fat meal and were then exposed to 6 h of intermittent hypoxaemia or ambient air. We show that postprandial triglyceride levels are significantly lower in women compared with men and that intermittent hypoxaemia leads to higher postprandial triglyceride levels in men only. These results might help us to understand better why women living with obstructive sleep apnoea experience lower rates of cardiometabolic diseases (e.g. type II diabetes and ischaemic heart disease) than men living with obstructive sleep apnoea.

Sleep-disordered breathing in children and adults with intellectual disability: mind the gap!

BACKGROUND: In adults and children with intellectual disability (ID), sleep -disordered breathing (SDB) is thought to be common. However, large epidemiological studies are lacking, and there are few studies on optimal methods of investigation and even fewer randomised, controlled intervention trials of treatment. METHOD: Peer-reviewed publications from various databases were examined in line with search terms relevant to ID and SDB spanning the years 200-2024. RESULTS: Findings suggest that, due to comorbid conditions, children and adults with ID may experience both an increased risk of SDB, as well as lower frequency of diagnosis. SDB can compromise the emotional, physical and mental health of individuals with ID. Appropriate treatment when tolerated leads to an improvement in health and well-being and several studies emphasized the importance of consistent follow-up of people with ID - something that is not universally occurring during childhood, in the transition to adulthood and during adulthood itself. As the most frequently occurring form of ID worldwide, we use Down syndrome as a specific example of how diagnosing and treating SDB can lead to improved outcomes. CONCLUSIONS: This review highlights the importance of identifying SDB in this heterogenous population, recognising the multi-faceted, deleterious consequences of untreated SDB in people with ID, and presents some strategies that can be harnessed to improve diagnosis and management. Until further ID-specific research is available, we urge flexibility in the approach to people with ID and SDB based in guidelines and standard practice developed for the typically developing population.

Association of positive airway pressure termination with mortality and non-fatal cardiovascular events in patients with obstructive sleep apnoea.

BACKGROUND AND AIMS: The recurrence of obstructive sleep apnoea (OSA) after positive airway pressure (PAP) therapy termination has physiological consequences that may increase cardiovascular (CV) risk. We aimed to determine whether PAP termination is associated with an increased incidence of major adverse CV events (MACE) compared with adherent PAP continuation. METHODS: Data from the Pays de la Loire Sleep Cohort were linked to the French national health insurance database to identify incident MACE (composite outcome of mortality, stroke and cardiac diseases), and CV active drug (lipid-lowering, antihypertensive and antiplatelet drugs, beta-blockers) adherence (medication possession ratio ≥80%). The association of PAP termination with MACE was evaluated using a time-dependent survival Cox model, with adjustment for confounders including CV active drug status. RESULTS: After a median follow-up of 8 years, 969 of 4188 included patients (median age 58 years, 69.6% men) experienced MACE, 1485 had terminated PAP while 2703 continued PAP with at least 4 hours/night use. 38% of patients were adherent to all CV drugs in the PAP continuation group versus 28% in the PAP termination group (p<0.0001). After adjustment for confounders, PAP termination was associated with an increased risk of MACE (HR (95% CI): 1.39 (1.20 to 1.62); p<0.0001). PAP termination was not associated with incident heart failure and coronary artery disease. CONCLUSIONS: In this multicentre clinical-based cohort involving 4188 patients with OSA, PAP termination compared with adherent PAP continuation was associated with an increased risk of MACE. More research is needed to determine whether support programmes on PAP adherence could improve CV outcomes.

Combination pharmacological therapy targeting multiple mechanisms of sleep apnoea: a randomised controlled cross-over trial.

RATIONALE: Acetazolamide and atomoxetine-plus-oxybutynin ('AtoOxy') can improve obstructive sleep apnoea (OSA) by stabilising ventilatory control and improving dilator muscle responsiveness respectively. Given the different pathophysiological mechanisms targeted by each intervention, we tested whether AtoOxy-plus-acetazolamide would be more efficacious than AtoOxy alone. METHODS: In a multicentre randomised crossover trial, 19 patients with moderate-to-severe OSA received AtoOxy (80/5 mg), acetazolamide (500 mg), combined AtoOxy-plus-acetazolamide or placebo at bedtime for three nights (half doses on first night) with a 4-day washout between conditions. Outcomes were assessed at baseline and night 3 of each treatment period. Mixed model analysis compared the reduction in Apnoea-Hypopnoea Index (AHI) from baseline between AtoOxy-plus-acetazolamide and AtoOxy (primary outcome). Secondary outcomes included hypoxic burden and arousal index. RESULTS: Although AtoOxy lowered AHI by 49 (33, 62)%baseline (estimate (95% CI)) vs placebo, and acetazolamide lowered AHI by+34 (14, 50)%baseline vs placebo, AtoOxy-plus-acetazolamide was not superior to AtoOxy alone (difference: -2 (-18, 11)%baseline, primary outcome p=0.8). Likewise, the hypoxic burden was lowered with AtoOxy (+58 (37, 71)%baseline) and acetazolamide (+37 (5, 58)%baseline), but no added benefit versus AtoOxy occurred when combined (difference: -13 (-5, 39)%baseline). Arousal index was also modestly reduced with each intervention (11%baseline-16%baseline). Mechanistic analyses revealed that similar traits (ie, higher baseline compensation, lower loop gain) were associated with both AtoOxy and acetazolamide efficacy. CONCLUSIONS: While AtoOxy halved AHI, and acetazolamide lowered AHI by a third, the combination of these leading experimental interventions provided no greater efficacy than AtoOxy alone. Failure of acetazolamide to further increase efficacy suggests overlapping physiological mechanisms. TRIAL REGISTRATION NUMBER: NCT03892772.

Effects of non-invasive ventilation on sleep in chronic hypercapnic respiratory failure.

Chronic respiratory disease can exacerbate the normal physiological changes in ventilation observed in healthy individuals during sleep, leading to sleep-disordered breathing, nocturnal hypoventilation, sleep disruption and chronic respiratory failure. Therefore, patients with obesity, slowly and rapidly progressive neuromuscular disease and chronic obstructive airways disease report poor sleep quality. Non-invasive ventilation (NIV) is a complex intervention used to treat sleep-disordered breathing and nocturnal hypoventilation with overnight physiological studies demonstrating improvement in sleep-disordered breathing and nocturnal hypoventilation, and clinical trials demonstrating improved outcomes for patients. However, the impact on subjective and objective sleep quality is dependent on the tools used to measure sleep quality and the patient population. As home NIV becomes more commonly used, there is a need to conduct studies focused on sleep quality, and the relationship between sleep quality and health-related quality of life, in all patient groups, in order to allow the clinician to provide clear patient-centred information.

High prevalence of severe sleep cycle disruption in de novo acromegaly and underdiagnosis by common clinical screening tools: A prospective, observational, cross-sectional study.

CONTEXT: Although sleep disordered breathing (SDB) is well-recognised in acromegaly, most studies have reported heterogeneous, often heavily treated, groups and few have performed detailed sleep phenotyping at presentation. OBJECTIVE: To study SDB using the gold standard of polysomnography, in the largest group of newly-diagnosed, treatment-naïve patients with acromegaly. SETTING AND PATIENTS: 40 patients [22 males, 18 females; mean age 54 years (range 23-78)], were studied to: (i) establish the prevalence and severity of SDB (ii) assess the reliability of commonly employed screening tools [Epworth Sleepiness Scale (ESS) and overnight oxygen desaturation index (DI)] to detect SDB (iii) determine the extent to which sleep architecture is disrupted. RESULTS: Obstructive sleep apnoea (OSA), defined by the apnoea-hypopnoea index (AHI), was present in 79% of subjects (mild, n = 12; moderate, n = 5; severe, n = 14). However, in these individuals with OSA by AHI criteria, ESS (positive in 35% [n = 11]) and DI (positive in 71%: mild, n = 11; moderate, n = 6; severe, n = 5) markedly underestimated its prevalence/extent. Seventy-eight percent of patients exhibited increased arousal, with marked disruption of the sleep cycle, despite most (82%) having normal total time asleep. Fourteen patients spent longer in stage 1 sleep. Deeper sleep stages were severely attenuated in many subjects (reduced stage 2, n = 18; reduced slow wave sleep, n = 24; reduced rapid eye movement sleep, n = 32). CONCLUSION: Our study provides strong support for clinical guidelines that recommend screening for sleep apnoea syndrome in patients with newly-diagnosed acromegaly. Importantly, however, it highlights shortcomings in commonly recommended screening tools (questionnaires, desaturation index) and demonstrates the added value of polysomnography to allow timely detection of obstructive sleep apnoea and associated sleep cycle disruption.

Follow-up of children with Down syndrome and sleep disordered breathing and the effects of treatment on actigraphically recorded sleep, quality of life, behaviour, and daytime functioning.

Children with Down syndrome are at increased risk of obstructive sleep disordered breathing, which has deleterious effects on daytime functioning. We aimed to examine the effects of treatment of sleep disordered breathing on sleep quality and daytime functioning in children with Down syndrome, and hypothesised that these would be improved. Thirty-four children completed a baseline study and a follow-up 2 years later. Measures at both time points included 7 days of actigraphy and parents completed a number of questionnaires assessing sleep, behaviour, daytime functioning, and quality of life. All children had overnight polysomnography at baseline; 15 children (44%) were treated. At baseline the treated group had more severe sleep disordered breathing compared with the untreated group: obstructive apneoa-hypopnoea index 29.3 ± 38.2 events/h versus 3.3 ± 5.2 events/h (p < 0.01). Actigraphy showed no significant differences in total sleep time, sleep efficiency, sleep schedules from baseline to follow up in either group. The sleep disturbance (p < 0.01) and total problems (p < 0.05) scales on the OSA-18 and the sleep disordered breathing subscale on the Paediatric Sleep Problem Survey Instrument (p < 0.01) improved in the treated children. There were no changes in any measure in the untreated children. Treatment of sleep disordered breathing improves symptoms, sleep disturbance and quality of life in children with Down syndrome, but has no demonstrable impact on actigraphic sleep measures or daytime behaviour or function. In contrast, children who were not treated, despite having less severe disease at baseline, had increased sleep disruption and no change in quality of life.

Clinical correlates of obstructive sleep apnoea in idiopathic normal pressure hydrocephalus.

BACKGROUND AND PURPOSE: The pathogenesis of idiopathic normal pressure hydrocephalus (iNPH) remains controversial. Limited studies have indicated a high prevalence of obstructive sleep apnoea (OSA) amongst iNPH patients. The aim was to investigate the clinical correlates of OSA in iNPH patients. METHODS: In this cross-sectional observational study, consecutive iNPH patients were prospectively enrolled. Evaluations included the iNPH Rating Scale, the Movement Disorder Society Unified Parkinson's Disease Rating Scale part III, the time and number of steps to walk 10 m, the Epworth Sleepiness Scale, the Pittsburgh Sleep Quality Index, a complete neuropsychological evaluation, 3-T brain MRI, full-night video-polysomnography, tap test and cerebrospinal fluid (CSF) neurodegeneration biomarkers. RESULTS: Fifty-one patients were screened, of whom 38 met the inclusion criteria. Amongst the recruited patients, 19/38 (50%) exhibited OSA, with 12/19 (63.2%) presenting moderate to severe disorder. OSA+ iNPH patients required more time (p = 0.02) and more steps (p = 0.04) to complete the 10-m walking test, had lower scores on the gait subitem of the iNPH Rating Scale (p = 0.04) and demonstrated poorer performance on specific neuropsychological tests (Rey Auditory Verbal Learning Test immediate recall, p = 0.03, and Rey-Osterrieth Complex Figure, p = 0.01). Additionally, OSA+ iNPH patients had higher levels of total tau (p = 0.02) and phospho-tau (p = 0.03) in their CSF but no statistically significant differences in beta-amyloid (1-42) levels compared to OSA- iNPH patients. CONCLUSION: Obstructive sleep apnoea is highly prevalent in iNPH patients, particularly at moderate to severe levels. OSA is associated with worse motor and cognitive performance in iNPH. The CSF neurodegeneration biomarker profile observed in OSA+ iNPH patients may reflect OSA-induced impairment of cerebral fluid dynamics.

Sleep apnoea symptoms and sleepiness associate with future diet quality: a prospective analysis in the Bogalusa Heart Study.

Sleep apnoea is a known risk factor for cardiometabolic diseases (CMD), but it is unknown whether sleep apnoea or its symptoms contribute to increased CMD through an association with diet quality. This study assessed the association between sleep apnoea symptoms on future diet quality in the Bogalusa Heart Study (BHS). This prospective study included 445 participants who completed a sleep apnoea questionnaire in 2007-2010 and a FFQ in 2013-2016 (mean follow-up: 5·8 years; age 43·5 years; 34 % male; 71 % White/29 % Black persons). Diet quality was measured with the Alternate Healthy Eating Index (AHEI) 2010, the Healthy Eating Index (HEI) 2015 and the alternate Mediterranean diet score. Adjusted mean differences in dietary patterns by sleep apnoea risk, excessive snoring and daytime sleepiness were estimated with multivariable linear regression. Models included multi-level socio-economic factors, lifestyle and health characteristics including BMI, physical activity and depressive symptoms. Those with high sleep apnoea risk, compared with low, had lower diet quality 5·8 years later (percentage difference in AHEI (95 % CI -2·1 % (-3·5 %, -0·7 %)). Daytime sleepiness was associated with lower diet quality. After adjusting for dietary pattern scores from 2001 to 2002, having high sleep apnoea risk and excessive sleepiness were associated with 1·5 % (P < 0·05) and 3·1 % (P < 0·001) lower future AHEI scores, respectively. These findings suggest that individuals with sleep apnea or excessive sleepiness should be monitored for diet quality and targeted for dietary interventions to improve CMD risk.

Obstructive sleep apnoea is independently associated with non-alcoholic fatty pancreatic disease.

PURPOSE: This study investigated the prevalence of non-alcoholic fatty pancreatic disease (NAFPD) in patients with obstructive sleep apnoea (OSA) and analysed the correlation between them. MATERIALS AND METHODS: Patients who underwent polysomnography and modified abdominal ultrasound examinations were continuously enrolled and divided into OSA and control groups. The OSA group was further divided into NAFPD and non-NAFPD groups. Differences in various indicators were compared. Binary logistic regression analyses were conducted to identify factors influencing NAFPD. RESULTS: A total of 210 participants were included in the study, including 178 in the OSA group and 32 in the control group. The prevalence of NAFPD, weight, body mass index (BMI), and other indicators were significantly higher in the OSA group than that in the control group (p < 0.05). The above indices, prevalence of hypertension and metabolic associated steatotic liver disease (MASLD), and severity of sleep apnoea were higher in the NAFPD group than that in the non-NAFPD group (p < 0.05). Binary logistic regression analysis showed a 4.4% increased risk of NAFPD for each unit increase in apnea-hypopnea index (AHI) after adjusting for BMI and hypertension. CONCLUSION: The prevalence of NAFPD was higher in the OSA group than that in the control group, and chronic intermittent hypoxia was strongly associated with pancreatic fat infiltration; AHI, BMI, and hypertension were independent risk factors for NAFPD. The NAFPD group had a higher prevalence of obesity and some other diseases.

This study confirms that the modified ultrasound evaluation method can serve as an effective tool for screening pancreatic fat infiltration in OSA patients, aiding in the early identification of the risk of ectopic lipid deposition and metabolic excess.

Catheter-based pulmonary vein isolation fails to prevent transient atrial arrhythmogenic changes related to acute obstructive respiratory events in a porcine model.

AIMS: Pulmonary vein isolation (PVI) is the corner stone of modern rhythm control strategies in patients with atrial fibrillation (AF). Sleep-disordered breathing (SDB) is prevalent in more than 50% of patients undergoing AF ablation, and studies have indicated a greater recurrence rate after PVI in patients with SDB. Herein, we study the effect of catheter-based PVI on AF in a pig model for SDB. METHODS AND RESULTS: In 11 sedated spontaneously breathing pigs, obstructive apnoeas were simulated by 75 s of intermittent negative upper airway pressure (INAP) applied by a negative pressure device connected to the endotracheal tube. Intermittent negative upper airway pressures were performed before and after PVI. AF-inducibility and atrial effective refractory periods (aERPs) were determined before and during INAP by programmed atrial stimulation. Pulmonary vein isolation prolonged the aERP by 48 ± 27 ms in the right atrium (RA) (P < 0.0001) and by 40 ± 34 ms in the left atrium (LA) (P = 0.0004). Following PVI, AF-inducibility dropped from 28 ± 26% to 0% (P = 0.0009). Intermittent negative upper airway pressure was associated with a transient aERP-shortening (ΔaERP) in both atria, which was not prevented by PVI (INAP indued ΔaERP after PVI in the RA: -57 ± 34 ms, P = 0.0002; in the LA: -42 ± 24 ms, P < 0.0001). Intermittent negative upper airway pressure was associated with a transient increase in AF-inducibility (from 28 ± 26% to 69 ± 21%; P = 0.0008), which was not attenuated by PVI [INAP-associated AF-inducibility after PVI: 58 ± 33% (P = 0.5)]. CONCLUSION: Transient atrial arrhythmogenic changes related to acute obstructive respiratory events are not prevented by electrical isolation of the pulmonary veins, which partially explains the increased AF recurrence in patients with SDB after PVI procedures.

A Position Modification Device for the Prevention of Supine Sleep During Pregnancy: A Randomised Crossover Trial.

OBJECTIVE: To assess the effectiveness and acceptability of a pillow-like position modification device to reduce supine sleep during late pregnancy, and to determine the impacts on the severity of sleep-disordered breathing (SDB) and foetal well-being. DESIGN: Randomised cross-over study. SETTING AND POPULATION: Individuals in the third trimester of pregnancy receiving antenatal care at a tertiary maternity hospital in Australia. METHODS: Participants used their own pillow for a control week and an intervention pillow for a week overnight, in randomised order. Sleep position and total sleep time for each night of both weeks were objectively monitored, with a sleep study and foetal heart rate monitoring performed on the last night of each week. MAIN OUTCOME MEASURES: Primary outcome = percentage of sleep time in the supine position; secondary outcomes = apnoea-hypopnoea index, foetal heart rate decelerations and birthweight centile. RESULTS: Forty-one individuals were randomised with data collected on 35 participants over 469 nights. There was no difference in percentage of total sleep time in the supine position overnight between the control or intervention pillow week (13.0% [6.1, 25.5] vs. 16.0% [5.6, 27.2], p = 0.81 with a mean difference of 2.5% [95% CI] = -0.7, 5.6, p = 0.12), and no difference in the severity of SDB or foetal heart rate decelerations across weeks. However, increased supine sleep was significantly related to a higher apnoea-hypopnoea index (rs = 0.37, p = 0.003), lower birthweight (rs = -0.45, p = 0.007) and lower birthweight centile (rs = -0.45, p = 0.006). The proportion of supine sleep each night of the week varied widely both within and across participants, despite awareness of side-sleeping recommendations. CONCLUSIONS: We found no evidence to suggest that the adoption of a pillow designed to discourage supine sleep was effective in late pregnancy, with women spending an average of 1 h per night supine. Alternative devices should be investigated, incorporating lessons learnt from this study to inform trials of supine sleep minimisation in pregnancy. TRIAL REGISTRATION: Clinical Trial: (Australia New Zealand Clinical Trials Registry): ACTRN12620000371998.

Assessment of obstructive sleep apnoea in children: What are the challenges we face?

There is an increasing demand for the assessment of sleep-disordered breathing in children of all ages to prevent the deleterious neurocognitive and behaviour consequences of the under-diagnosis and under-treatment of obstructive sleep apnoea [OSA]. OSA can be considered in three broad categories based on predominating contributory features: OSA type 1 [enlarged tonsils and adenoids], type II [Obesity] and type III [craniofacial abnormalities, syndromal, storage diseases and neuromuscular conditions]. The reality is that sleep questionnaires or calculations of body mass index in isolation are poorly predictive of OSA in individuals. Globally, the access to testing in tertiary referral centres is comprehensively overwhelmed by the demand and financial cost. This has prompted the need for better awareness and focussed history taking, matched with simpler tools with acceptable accuracy used in the setting of likely OSA. Consequently, we present key indications for polysomnography and present scalable, existing alternatives for assessment of OSA in the hospital or home setting, using polygraphy, oximetry or contactless sleep monitoring.

OSA type-III and neurocognitive function.

Obstructive sleep apnea (OSA) due to a hypertrophy of the adenoids and/or the tonsils in otherwise healthy children is associated with neurocognitive dysfunction and behavioural disorders with various degrees of hyperactivity, aggressiveness, sometimes evolving to a label of attention-deficit hyperactivity disorder. Children with anatomical and/or functional abnormalities of the upper airways represent a very specific population which is at high risk of OSA (also called complex OSA or OSA type III). Surprisingly, the neurocognitive consequences of OSA have been poorly studied in these children, despite the fact that OSA is more common and more severe than in their healthy counterparts. This may be explained by that fact that screening for OSA and sleep-disordered breathing is not systematically performed, the performance of sleep studies and neurocognitive tests may be challenging, and the respective role of the underlining disease, OSA, but also poor sleep quality, is complex. However, the few studies that have been performed in these children, and mainly children with Down syndrome, tend to show that OSA, but even more disruption of sleep architecture and poor sleep quality, aggravate the neurocognitive impairment and abnormal behaviour in these patients, underlining the need for a systematic and early in life assessment of sleep and neurocognitive function and behaviour in children with OSA type III.

Opioid sensitivity in treated and untreated obstructive sleep apnoea: a prospective cohort study.

BACKGROUND: Opioid administration to patients with obstructive sleep apnoea (OSA) is controversial because they are believed to be more sensitive to opioids. However, objective data on opioid effects in OSA are lacking. We tested the hypothesis that subjects with untreated OSA have increased sensitivity to opioids compared with subjects without OSA, or with OSA treated with continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BIPAP). METHODS: This was a single-centre, prospective cohort study in subjects without OSA (n=20), with untreated OSA (n=33), or with treated OSA (n=21). OSA diagnosis was verified using type III (in-home) polysomnography. Subjects received a stepped-dose remifentanil infusion (target effect-site concentrations of 0.5, 1, 2, 3, 4 ng ml-1). Primary outcome was miosis (pupil area fractional change), the most sensitive opioid effect. Secondary outcomes were ventilatory rate, end-expired CO2, sedation, and thermal analgesia. RESULTS: There were no differences in miosis between untreated OSA subjects (mean=0.51, 95% confidence interval [CI] 0.41-0.61) and subjects without OSA (mean=0.49, 95% CI 0.36-0.62) (mean difference=0.02, 95% CI -0.18 to 0.22); between treated OSA subjects (mean=0.56, 95% CI 0.43-0.68) and subjects without OSA (difference=0.07, 95% CI -0.16 to 0.29); or between untreated OSA and treated OSA (difference=-0.05, 95% CI -0.25 to 0.16). There were no significant differences between subjects without OSA, untreated OSA, and treated OSA in ventilatory rate, end-expired CO2, sedation, or thermal analgesia responses to remifentanil. There was no relationship between OSA severity and magnitude of opioid effects. CONCLUSIONS: Neither obstructive sleep apnoea nor obstructive sleep apnoea treatment affected sensitivity to the miotic, sedative, analgesic, or respiratory depressant effects of the opioid remifentanil in awake adults. These results challenge conventional notions of opioid effects in obstructive sleep apnoea. CLINICAL TRIAL REGISTRATION: NCT02898792 (clinicaltrials.gov).

Impact of spinal versus general anaesthesia on perioperative obstructive sleep apnoea severity in patients undergoing hip arthroplasty: a post hoc analysis of two randomised controlled trials.

BACKGROUND: Recommendations suggest favouring regional over general anaesthesia to reduce impact on postoperative sleep apnoea severity, but there is currently no evidence to support this. We compared the impact of general vs spinal anaesthesia on postoperative sleep apnoea severity and assessed the evolution of sleep apnoea severity up to the third postoperative night. METHODS: This post hoc analysis used pooled data from two previous randomised controlled trials in patients undergoing total hip arthroplasty under general or spinal anaesthesia (n=96), without performing a preliminary power analysis. All participants underwent respiratory polygraphy before surgery and on the first and third postoperative nights. The primary outcomes were the supine apnoea-hypopnea index on the first postoperative night and the evolution of the supine apnoea-hypopnea index up to the third postoperative night. Secondary outcomes included the oxygen desaturation index on the first and third postoperative nights. RESULTS: In the general and spinal anaesthesia groups, mean (95% confidence interval) values for the supine apnoea-hypopnoea index on the first postoperative night were 20 (16-25) and 21 (16-26) events h-1 (P=0.82), respectively; corresponding values on the third postoperative night were 34 (22-45) and 35 (20-49) events h-1 (P=0.91). The generalised estimating equations model showed a significant time effect. Secondary outcomes were similar in the two groups. CONCLUSIONS: Use of spinal anaesthesia compared with general anaesthesia was not associated with a reduction in postoperative sleep apnoea severity, which was worse on the third postoperative night. CLINICAL TRIAL REGISTRATION: NCT02717780 and NCT02566226.

Measuring immediate surgical success in children undergoing adenotonsillectomy.

Adenotonsillectomy is the most common indication for sleep-disordered breathing in children. Measuring pharyngeal closing pressures in anaesthetised children allows identification of severe obstructive sleep apnoea. This technique could help quantify immediate surgical impact and risk stratify postoperative treatment in these patients.

Portable polygraphic device (Somnocheck micro CARDIO®) provides accurate diagnostic information in psychiatric patients at risk for obstructive sleep apnoea: an observational cohort study.

BACKGROUND: Symptoms of obstructive sleep apnoea (OSA) overlap significantly with those of psychiatric disorders, making accurate diagnosis of OSA challenging within psychiatric settings. Diagnosing OSA in psychiatric patients is crucial because untreated OSA can exacerbate psychiatric symptoms, reduce treatment efficacy, and impair overall quality of life. This study aimed to determine the diagnostic accuracy of a readily accessible procedure for psychiatric patients in a real-world clinical setting by comparing the Somnocheck micro CARDIO® (SCm) portable cardiorespiratory polygraphy device with the gold standard polysomnography (PSG). METHODS: This observational cohort study included consecutive psychiatric patients at intermediate to high risk for OSA based on screening with the STOP-Bang questionnaire, admitted to a single tertiary care centre between June 1, 2016 and December 31, 2022. The Apnoea-Hypopnoea-Index (AHI), Apnoea-Index (AI), Oxygen-Desaturation-Index (ODI), and minimum oxygen saturation were measured sequentially by SCm and PSG. RESULTS: A total of 57 patients were analysed (median age 62.0 [Interquartile Range (IQR), 51.5-72.5] years; 34 [59.6%] men). Regarding AHI, no significant differences (AHI measured by PSG, median, 16.6 [IQR, 6.2-26.7] vs. AHI measured by SCm, median, 14.9 [IQR, 10.0-22.8]; p = 0.812; r = 0.71) were found between SCm and PSG. AI, ODI and minimum oxygen saturation differed significantly between SCm and PSG. Using optimised cut-off values (any OSA: AHISCm ≥ 9.25), SCm showed high sensitivity (0.894) and high specificity (0.800) for the diagnosis of OSA, with an area under the receiver operating characteristic curve of 0.877. CONCLUSIONS: This study found that the SCm portable device was accurate in identifying psychiatric patients with OSA. AHI measurement by SCm provided reliable diagnostic performance in comparison with the gold standard polysomnography. These findings support the integration of polygraphic measurements into the routine sleep assessment of psychiatric patients. Early and accurate diagnosis of OSA in this population can significantly improve the management of both sleep disorders and psychiatric conditions, potentially enhancing overall treatment outcomes and quality of life for these patients.

Associations of early life and childhood risk factors with obstructive sleep apnoea in middle-age.

BACKGROUND AND OBJECTIVE: Early-life risk factors for obstructive sleep apnoea (OSA) are poorly described, yet this knowledge may be critical to inform preventive strategies. We conducted the first study to investigate the association between early-life risk factors and OSA in middle-aged adults. METHODS: Data were from population-based Tasmanian Longitudinal Health Study cohort (n = 3550) followed from 1st to 6th decades of life. Potentially relevant childhood exposures were available from a parent-completed survey at age 7-years, along with previously characterized risk factor profiles. Information on the primary outcome, probable OSA (based on a STOP-Bang questionnaire cut-off ≥5), were collected when participants were 53 years old. Associations were examined using logistic regression adjusting for potential confounders. Analyses were repeated using the Berlin questionnaire. RESULTS: Maternal asthma (OR = 1.5; 95% CI 1.1-2.0), maternal smoking (OR = 1.2; 1.05, 1.5), childhood pleurisy/pneumonia (OR = 1.3; 1.04, 1.7) and frequent bronchitis (OR = 1.2; 1.01, 1.5) were associated with probable OSA. The risk-factor profiles of 'parental smoking' and 'frequent asthma and bronchitis' were also associated with probable OSA (OR = 1.3; 1.01, 1.6 and OR = 1.3; 1.01-1.9, respectively). Similar associations were found for Berlin questionnaire-defined OSA. CONCLUSIONS: We found novel temporal associations of maternal asthma, parental smoking and frequent lower respiratory tract infections before the age of 7 years with adult OSA. While determination of their pathophysiological and any causal pathways require further research, these may be useful to flag the risk of OSA within clinical practice and create awareness and vigilance among at-risk groups.