Obstructive sleep apnoea in adults

Obstructive sleep apnoea (OSA) is characterised by repetitive closure of the upper airway, repetitive oxygen desaturations and sleep fragmentation. The prevalence of adult OSA is increasing because of a worldwide increase in obesity and the ageing of populations. OSA presents with a variety of symptoms the most prominent of which are snoring and daytime tiredness. Interestingly though, a significant proportion of OSA sufferers report little or no daytime symptoms. OSA has been associated with an increased risk of cardiovascular disease, cognitive abnormalities and mental health problems. Randomised controlled trial evidence is awaited to confirm a causal relationship between OSA and these various disorders. The gold standard diagnostic investigation for OSA is overnight laboratory-based polysomnography (sleep study), however, ambulatory models of care incorporating screening questionnaires and home sleep studies have been recently evaluated and are now being incorporated into routine clinical practice. Patients with OSA are very often obese and exhibit a range of comorbidities, such as hypertension, depression and diabetes. Management, therefore, needs to be based on a multidisciplinary and holistic approach which includes lifestyle modifications. Continuous positive airway pressure (CPAP) is the first-line therapy for severe OSA. Oral appliances should be considered in patients with mild or moderate disease, or in those unable to tolerate CPAP. New, minimally invasive surgical techniques are currently being developed to achieve better patient outcomes and reduce surgical morbidity. Successful longterm management of OSA requires careful patient education, enlistment of the family’s support and the adoption of self-management and patient goal-setting principles.Australian National Health and Medical Research Counci

Global warming and increased sleep disordered breathing mortality, rising carbon dioxide levels are a serial pest

This article appeared in a journal published by Wiley-Blackwell. Under Wiley's copyright, mandated authors are not permitted to make work available in an institutional repository.Sleep disordered breathing is such a common clinical problem. We do many diagnostic polysomnograms (PSGS) each year around the world. Should we be collecting more information as part of the testing process to guide decision making? In this issue, Brillante et al. report on an intriguing retrospective study which suggests that an overnight increase in carbon dioxide levels (>7mm Hg) and evening hypoxemia (PO2 < 65mm Hg) preceding a diagnostic polysomnogram (PSG) predicted long-term mortality in sleep disordered breathing.Australian National Health & Medical Research Counci

The impact of ethnicity on the prevalence and severity of obstructive sleep apnea

This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. This author accepted manuscript is made available following 12 month embargo from date of publication (February 2018) in accordance with the publisher’s archiving policyObstructive sleep apnea (OSA) is a common disorder associated with multiple adverse health consequences and its prevalence is increasing in parallel with rising obesity trends. Early support for ethnic differences in OSA prevalence and severity has been derived from studies of relatively homogenous ethnic groups. However, between-study comparisons are problematic given differing methodologies. Recent large inter-ethnic studies examining different ethnic populations using standardized protocols support the notion that Chinese have an increased OSA prevalence and severity compared to those of European descent. Although the evidence is less clear, some data suggest that Hispanic/Mexican Americans also show higher rates of OSA, while OSA prevalence in African Americans is not dissimilar to that of populations of European ancestry. Of the anatomical traits underlying differences in OSA prevalence and severity between ethnic groups (i.e., obesity, fat distribution, and craniofacial structure) obesity appears to be the most important. The effect of ethnicity on non-anatomical factors (i.e., upper airway muscle responsiveness, arousal threshold, and loop gain) responsible for OSA severity and potentially prevalence is currently unknown and needs further research.None

Sleep Disordered Breathing and Chronic Respiratory Failure in Patients with Chronic Pain on Long Term Opioid Therapy

Author manuscript freely available online at PubMed Central STUDY OBJECTIVES: The use of opioid medication for chronic pain has been increasing. The main aim of this study was to assess how many patients on opioids for chronic pain had sleep disordered breathing (SDB) and the type of SDB. The impact of these medications on daytime arterial blood gas (ABG) measurements and psychomotor vigilance was also studied. METHODS: Twenty-four patients (aged 18-75 years) on long-term opioids were prospectively recruited. Patients underwent home polysomnogram (PSG), psychomotor vigilance testing (PVT), and awake daytime ABG. Overnight PSG findings were compared to those of patients matched for age, sex, and BMI referred to our sleep service for evaluation of SDB. PVT results in the patient cohort were compared to PVT in healthy controls. RESULTS: Forty-six percent of opioid patients had severe SDB as defined by an apnea hypopnea index (AHI) > 30/h. The severity of SDB was similar in opioid-treated pain clinic patients and sleep clinic patients (mean ± SD AHI: Opioid-treated patients 32.7 ± 25.6; Sleep Study comparator group 28.9 ± 24.6, p = 0.6). Opioid patients had a higher frequency of central apneas and a lower arousal index (CAI: 3.9 ± 8.3 vs. 0.3 ± 0.5 events/h; p = 0.004, AI 8.0 ± 4.1 vs. 20.1 ± 13.8, p < 0.001). Pain clinic patients had impaired gas exchange during sleep and wakefulness. Nine of 20 (45%) had daytime hypercapnia, indicating a surprising number were in chronic respiratory failure. Morphine equivalent doses correlated with the severity of SDB. PVT was impaired when compared to a healthy PVT comparator group (RT: Opioid-treated patients 0.43 ± 0.27: Healthy PVT comparator group 0.28 ± 0.03 sec; p < 0.001). CONCLUSIONS: Patients on long-term opioids frequently have severe SDB, which in part is central in origin. PVT was markedly impaired. Half of the patients studied have evidence of chronic ventilatory failure. COMMENTARY: A commentary on this article appears in this issue on page 85

The relationship between functional health literacy and obstructive sleep apnea and its related risk factors and comorbidities in a population cohort of men

Author manuscript version freely available online at PubMed Central STUDY OBJECTIVES: To examine the relationship between functional health literacy (FHL) and obstructive sleep apnea (OSA), its diagnosis, related risk factors, and comorbidities. DESIGN: Population cohort study. SETTING: Adelaide, South Australia, 2011-12. PARTICIPANTS: 1,021 Men Androgen Inflammation Lifestyle Environment and Stress Study participants aged ≥ 40 years, of whom 627 were identified with OSA by self-report (n = 184 previously diagnosed) or with in-home polysomnography in 837 randomly selected participants without self-reported OSA (n = 443 previously undiagnosed). INTERVENTIONS: The Newest Vital Sign assessed FHL in 88% of participants. Full in-home unattended polysomnography (Embletta X100) was scored by 2007 AASM (alternative) criteria. MEASUREMENTS AND RESULTS: FHL was adequate in 75.3% (n = 122) of previously diagnosed and 68.3% (n = 261) of previously undiagnosed OSA. Not having a previous diagnosis was independently associated with inadequate FHL (odds ratio [OR]:2.84, 95% confidence interval [CI]:1.25-6.45) and workforce participation (OR = 2.04, 95% CI = 1.01-4.00), and inversely associated with previous snoring (OR = 0.48, 95% CI = 0.29-0.81), obesity (OR = 0.35, 95% CI = 0.15-0.81), and cardiovascular disease (OR = 0.45, 95% CI = 0.24-0.85). In polysomnography participants, inadequate FHL was independently associated with previously undiagnosed OSA (OR = 2.43, 95% CI = 1.40-4.20). In undiagnosed men, less than adequate FHL was independently associated with sedentary lifestyle (OR = 2.42, 95% CI = 1.36-4.29), and depression (OR = 2.50, 95% CI = 1.23-5.09) and inadequate FHL was associated with current smoking (OR = 2.87, 95% CI = 1.21-6.84). The depression association was attenuated after additional adjustment for comorbidities and general health (OR = 2.04, 95% CI = 0.93-4.49, P = 0.076). In previously diagnosed OSA, less than adequate FHL was independently associated with cardiovascular disease (OR = 2.76, 95% CI = 1.09-7.01). CONCLUSIONS: Limited functional health literacy was independently associated with obstructive sleep apnea (OSA), OSA diagnosis, lifestyle factors and comorbidities, highlighting the importance of developing and promoting national disease-specific health literacy policies

Nocturnal Hypoxemia and Severe Obstructive Sleep Apnea are Associated with Incident Type 2 Diabetes in a Population Cohort of Men

Freely available online at PubMed Central Study Objectives Studies examining the longitudinal association of untreated obstructive sleep apnea (OSA) with diabetes in population samples are limited. This study therefore examined the relationship between previously undiagnosed OSA with incident type 2 diabetes in community-dwelling men aged ≥ 40 y. Methods The Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) Study is a longitudinal population-based cohort in Adelaide, South Australia. Clinic assessments at baseline and follow-up identified diabetes (self-reported doctor diagnosed, fasting plasma glucose ≥ 7.0 mmol/L, glycated hemoglobin ≥ 6.5% or diabetes medication use) and included anthropometry. At cohort follow-up (2010–2012), n = 837 underwent full in-home unattended polysomnography (PSG, Embletta X100, Broomfield, CO). Results Of 736 men free of diabetes at baseline, incident diabetes occurred in 66 (9.0%) over a mean follow-up time of 56 mo (standard deviation = 5, range: 48–74 mo). Incident diabetes was associated with current oxygen desaturation index (3%) ≥ 16 events/h (odds ratio [OR]: 1.85 [1.06–3.21]), and severe OSA [OR: 2.6 (1.1–6.1)], in adjusted models including age, percentage total body fat, and weight gain (> 5 cm waist circumference). An age-adjusted association of incident diabetes with percentage of total sleep time with oxygen saturation < 90% did not persist after adjustment for percentage of body fat. No modification of these relationships by excessive daytime sleepiness was observed. Conclusions Severe undiagnosed OSA and nocturnal hypoxemia were independently associated with the development of diabetes. A reduction in the burden of undiagnosed OSA and undiagnosed diabetes is likely to occur if patients presenting with one disorder are assessed for the other

The Sleep Apnea cardioVascular Endpoints (SAVE) Trial: Rationale, Ethics, Design, and Progress

Freely available online from PubMed Central ABSTRACT: The Sleep Apnea cardioVascular Endpoints (SAVE) study is an ongoing investigator-initiated and conducted, international, multicenter, open, blinded endpoint, randomized controlled trial that was designed to determine whether treatment of obstructive sleep apnea (OSA) with continuous positive airways pressure (CPAP) can reduce the risk of serious cardiovascular (CV) events in patients with established CV disease (clinical trial registration NCT00738179). The results of this study will have important implications for the provision of health care to patients with sleep apnea around the world. The SAVE study has brought together respiratory, sleep, CV and stroke clinicians-scientists in an interdisciplinary collaboration with industry and government sponsorship to conduct an ambitious clinical trial. Following its launch in Australia and China in late 2008, the recruitment network expanded across 89 sites that included New Zealand, India, Spain, USA, and Brazil for a total of 2,717 patients randomized by December 2013. These patients are being followed until December 2015 so that the average length of follow-up of the cohort will be over 4 y. This article describes the rationale for the SAVE study, considerations given to the design including how various cultural and ethical challenges were addressed, and progress in establishing and maintaining the recruitment network, patient follow-up, and adherence to CPAP and procedures. The assumptions underlying the original trial sample size calculation and why this was revised downward in 2012 are also discussed. CLINICAL TRIALS REGISTRATION NUMBER: NCT00738179. AUSTRALIA NEW ZEALAND CLINICAL TRIALS REGISTRY NUMBER: ACTRN12608000409370

Aggressive risk factor reduction study for atrial fibrillation and implications for the outcome of ablation: the ARREST-AF cohort study

Version of record (Published version) freely available online at Publisher website BACKGROUND: The long-term outcome of atrial fibrillation (AF) ablation demonstrates attrition. This outcome may be due to failure to attenuate the progressive substrate promoted by cardiovascular risk factors. OBJECTIVES: The goal of this study was to evaluate the impact of risk factor and weight management on AF ablation outcomes. METHODS: Of 281 consecutive patients undergoing AF ablation, 149 with a body mass index ≥27 kg/m(2) and ≥1 cardiac risk factor were offered risk factor management (RFM) according to American Heart Association/American College of Cardiology guidelines. After AF ablation, all 61 patients who opted for RFM and 88 control subjects were assessed every 3 to 6 months by clinic review and 7-day Holter monitoring. Changes in the Atrial Fibrillation Severity Scale scores were determined. RESULTS: There were no differences in baseline characteristics, number of procedures, or follow-up duration between the groups (p = NS). RFM resulted in greater reductions in weight (p = 0.002) and blood pressure (p = 0.006), and better glycemic control (p = 0.001) and lipid profiles (p = 0.01). At follow-up, AF frequency, duration, symptoms, and symptom severity decreased more in the RFM group compared with the control group (all p < 0.001). Single-procedure drug-unassisted arrhythmia-free survival was greater in RFM patients compared with control subjects (p < 0.001). Multiple-procedure arrhythmia-free survival was markedly better in RFM patients compared with control subjects (p < 0.001), with 16% and 42.4%, respectively, using antiarrhythmic drugs (p = 0.004). On multivariate analysis, type of AF (p < 0.001) and RFM (hazard ratio 4.8 [95% confidence interval: 2.04 to 11.4]; p < 0.001) were independent predictors of arrhythmia-free survival. CONCLUSIONS: Aggressive RFM improved the long-term success of AF ablation. This study underscores the importance of therapy directed at the primary promoters of the AF substrate to facilitate rhythm control strategies