Comparative Effectiveness of Supine Avoidance versus Continuous Positive Airway Pressure for Treating Supine-isolated Sleep Apnea: A Clinical Trial

Rationale: About 20-35% of patients with obstructive sleep apnea (OSA) have supine-isolated OSA, for which supine sleep avoidance could be an effective therapy. However, traditional supine discomfort-based methods show poor tolerance and compliance to treatment and so cannot be recommended. Supine alarm devices show promise, but evidence to support favorable adherence to treatment and effectiveness at reducing excessive daytime sleepiness compared with continuous positive airway pressure (CPAP) remains limited. Objectives: To establish if alarm-based supine-avoidance treatment in patients with supine-isolated OSA is noninferior to CPAP in reducing daytime sleepiness. Methods: After baseline questionnaire administration and in-home supine-time and polysomnography assessments, patients with supine-isolated OSA and Epworth Sleepiness Scale scores ⩾8 were randomized to ⩾6 weeks of supine-avoidance or CPAP treatment, followed by crossover to the remaining treatment with repeat assessments. Noninferiority was assessed from change in Epworth Sleepiness Scale with supine avoidance compared with CPAP using a prespecified noninferiority margin of 1.5. Average nightly treatment use over all nights and treatment efficacy and effectiveness at reducing respiratory disturbances were also compared between treatments. Results: The reduction in sleepiness score with supine avoidance (mean [95% confidence interval], -1.9 [-2.8 to -1.0]) was noninferior to that with CPAP (-2.4 [-3.3 to -1.4]) (supine avoidance-CPAP difference, -0.4 [-1.3 to 0.6]), and the lower confidence limit did not cross the noninferiority margin of 1.5 (P = 0.021). Average treatment use was higher with supine avoidance compared with CPAP (mean ± standard deviation, 5.7 ± 2.4 vs. 3.9 ± 2.7 h/night; P < 0.001). Conclusions: In patients with supine-isolated OSA, vibrotactile supine alarm device therapy is noninferior to CPAP for reducing sleepiness and shows superior treatment adherence. Clinical trial registered with www.anzctr.org.au (ACTRN 12613001242718).

Effect of depression, anxiety, and stress symptoms on response to cognitive behavioral therapy for insomnia in patients with comorbid insomnia and sleep apnea: a randomized controlled trial

STUDY OBJECTIVES

Patients with comorbid insomnia and sleep apnea (COMISA) report increased severity of depression, anxiety, and stress symptoms compared to patients with either insomnia or sleep apnea alone. Although cognitive behavioral therapy for insomnia (CBTi) is an effective treatment for COMISA, previous research suggests a reduced response to CBTi by patients with insomnia and depression, anxiety, and stress symptoms. Therefore, we used randomized controlled trial data to investigate the impact of depression, anxiety, and stress symptoms before treatment on changes in insomnia after CBTi vs control in patients with COMISA.

METHODS

145 patients with COMISA (insomnia as defined by the International Classification of Sleep Disorders, third edition and apnea-hypopnea index ≥ 15 events/h) were randomized to CBTi (n = 72) or no-treatment control (n = 73). One-week sleep diaries and standardized questionnaire measures of insomnia, sleepiness, fatigue, depression, anxiety, and stress were completed pretreatment and posttreatment. Mixed models were used to examine interactions between depression, anxiety, and stress symptoms before treatment, intervention-group (CBTi, control), and time (pretreatment, posttreatment) on insomnia symptoms.

RESULTS

Approximately half of this COMISA sample reported at least mild symptoms of depression (57%), anxiety (53%), and stress (48%) before treatment. Patients reporting greater depression, anxiety, and stress symptoms before treatment also reported increased severity of insomnia, daytime fatigue, and sleepiness. Improvements in questionnaire and diary-measured insomnia symptoms improved during CBTi and were not moderated by severity of depression, anxiety, or stress symptoms before treatment (all interaction P ≥ .11).

CONCLUSIONS

We found no evidence that symptoms of depression, anxiety, or stress impair the effectiveness of CBTi in improving insomnia symptoms in patients with COMISA. Patients with COMISA and comorbid symptoms of depression, anxiety, and stress should be referred for CBTi to treat insomnia and improve subsequent management of their obstructive sleep apnea.

CLINICAL TRIAL REGISTRATION

Registry: Australian New Zealand Clinical Trials Registry; Name: Treating comorbid insomnia with obstructive sleep apnea (COMISA) study: A new treatment strategy for patients with combined insomnia and sleep apnea; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=365184; Identifier: ACTRN12613001178730.

Polysomnographic Predictors of Treatment Response to Cognitive Behavioral Therapy for Insomnia in Participants With Co-morbid Insomnia and Sleep Apnea: Secondary Analysis of a Randomized Controlled Trial

OBJECTIVE

Co-morbid insomnia and sleep apnea (COMISA) is a common and debilitating condition that is more difficult to treat compared to insomnia or sleep apnea-alone. Emerging evidence suggests that cognitive behavioral therapy for insomnia (CBTi) is effective in patients with COMISA, however, those with more severe sleep apnea and evidence of greater objective sleep disturbance may be less responsive to CBTi. Polysomnographic sleep study data has been used to predict treatment response to CBTi in patients with insomnia-alone, but not in patients with COMISA. We used randomized controlled trial data to investigate polysomnographic predictors of insomnia improvement following CBTi, versus control in participants with COMISA.

METHODS

One hundred and forty five participants with insomnia (ICSD-3) and sleep apnea [apnea-hypopnea index (AHI) ≥ 15] were randomized to CBTi (n = 72) or no-treatment control (n = 73). Mixed models were used to investigate the effect of pre-treatment AHI, sleep duration, and other traditional (AASM sleep macrostructure), and novel [quantitative electroencephalography (qEEG)] polysomnographic predictors of between-group changes in Insomnia Severity Index (ISI) scores from pre-treatment to post-treatment.

RESULTS

Compared to control, CBTi was associated with greater ISI improvement among participants with; higher AHI (interaction p = 0.011), less wake after sleep onset (interaction p = 0.045), and less N3 sleep (interaction p = 0.005). No quantitative electroencephalographic, or other traditional polysomnographic variables predicted between-group ISI change (all p > 0.09).

DISCUSSION

Among participants with COMISA, higher OSA severity predicted a greater treatment-response to CBTi, versus control. People with COMISA should be treated with CBTi, which is effective even in the presence of severe OSA and objective sleep disturbance.

Cognitive and behavioral therapy for insomnia increases the use of continuous positive airway pressure therapy in obstructive sleep apnea participants with comorbid insomnia: a randomized clinical trial

STUDY OBJECTIVES

Insomnia and obstructive sleep apnea (OSA) commonly co-occur which makes OSA difficult to treat with continuous positive airway pressure (CPAP). We conducted a randomized controlled trial in participants with OSA and co-occurring insomnia to test the hypothesis that initial treatment with cognitive and behavioral therapy for insomnia (CBT-i), versus treatment as usual (TAU) would improve insomnia symptoms and increase subsequent acceptance and use of CPAP.

METHODS

One hundred and forty-five participants with OSA (apnea-hypopnea index ≥ 15) and comorbid insomnia were randomized to either four sessions of CBT-i, or TAU, before commencing CPAP therapy until 6 months post-randomization. Primary between-group outcomes included objective average CPAP adherence and changes in objective sleep efficiency by 6 months. Secondary between-group outcomes included rates of immediate CPAP acceptance/rejection, and changes in; sleep parameters, insomnia severity, and daytime impairments by 6 months.

RESULTS

Compared to TAU, participants in the CBT-i group had 61 min greater average nightly adherence to CPAP (95% confidence interval [CI] = 9 to 113; p = 0.023, d = 0.38) and higher initial CPAP treatment acceptance (99% vs. 89%; p = 0.034). The CBT-i group showed greater improvement of global insomnia severity, and dysfunctional sleep-related cognitions by 6 months (both: p < 0.001), and greater improvement in sleep impairment measures immediately following CBT-i. There were no between-group differences in sleep outcomes, or daytime impairments by 6 months.

CONCLUSIONS

In OSA participants with comorbid insomnia, CBT-i prior to initiating CPAP treatment improves CPAP use and insomnia symptoms compared to commencing CPAP without CBT-i. OSA patients should be evaluated for co-occurring insomnia and considered for CBT-i before commencing CPAP therapy.

CLINICAL TRIAL

Treating comorbid insomnia with obstructive sleep apnea (COMSIA) study: A new treatment strategy for patients with combined insomnia and sleep apnea, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=365184 Australian New Zealand Clinical Trials Registry: ACTRN12613001178730. Universal Trial Number: U1111-1149-4230.

Cognitive behavioural therapy for insomnia reduces sleep apnoea severity: a randomised controlled trial

Insomnia and obstructive sleep apnoea (OSA) frequently co-occur and may be causally related through sleep fragmentation and/or hyperarousal mechanisms. Previous studies suggest that OSA treatment can improve insomnia severity. However, the effect of insomnia treatment on OSA severity has not been investigated. We performed a randomised controlled trial to investigate the effect of cognitive behavioural therapy for insomnia (CBTi) on OSA severity, controlling for potential sleep-stage and posture effects. 145 patients with comorbid insomnia (International Classification of Sleep Disorders, 3rd Edn) and untreated OSA (apnoea-hypopnoea index (AHI) ≥15 events·h-1 sleep) were randomised to a four-session CBTi programme or to a no-treatment control. Overnight sleep studies were completed pre- and post-treatment to measure AHI, arousal index and sleep architecture, to investigate the effect of intervention group, time, sleep stage (N1-3 or REM) and posture (supine or nonsupine) on OSA severity. The CBTi group showed a 7.5 event·h-1 greater AHI difference (mean (95% CI) decrease 5.5 (1.3-9.7) events·h-1, Cohen's d=0.2, from 36.4 events·h-1 pre-treatment) across sleep-stages and postures, compared to control (mean increase 2.0 (-2.0-6.1) events·h-1, d=0.01, from 37.5 events·h-1 at pre-treatment; interaction p=0.012). Compared to control, the CBTi group also had a greater reduction in total number (mean difference 5.6 (0.6-10.6) greater overall reduction; p=0.029) and duration of nocturnal awakenings (mean difference 21.1 (2.0-40.3) min greater reduction; p=0.031) but showed no difference in the arousal index, or sleep architecture. CBTi consolidates sleep periods and promotes a 15% decrease in OSA severity in patients with comorbid insomnia and OSA. This suggests that insomnia disorder may exacerbate OSA and provides further support for treating insomnia in the presence of comorbid OSA.

The effect of cognitive and behavioral therapy for insomnia on week-to-week changes in sleepiness and sleep parameters in patients with comorbid insomnia and sleep apnea: a randomized controlled trial

Study Objectives

While cognitive and behavioral therapy for insomnia (CBTi) is an effective treatment in patients with comorbid moderate and severe obstructive sleep apnea (OSA), there is concern that the bedtime restriction component of CBTi might dangerously exacerbate daytime sleepiness in such patients. We examined randomized controlled trial data to investigate the effect of OSA severity, and pretreatment daytime sleepiness on week-to-week changes in daytime sleepiness and sleep parameters during CBTi and no-treatment control.

Methods

One hundred and forty-five patients with untreated physician-diagnosed OSA (apnea–hypopnea index ≥15) and psychologist-diagnosed insomnia (ICSD-3) were randomized to a 4-week CBTi program (n = 72) or no-treatment control (n = 73). The Epworth sleepiness scale (ESS) and sleep diaries were completed during pretreatment, weekly CBTi sessions, and posttreatment. Effects of OSA severity, pretreatment daytime sleepiness, and intervention group on weekly changes in daytime sleepiness and sleep parameters were investigated.

Results

The CBTi group reported a 15% increase in ESS scores following the first week of bedtime restriction (M change = 1.3 points, 95% CI = 0.1–2.5, p = 0.031, Cohen’s d = 0.27) which immediately returned to pretreatment levels for all subsequent weeks, while sleep parameters gradually improved throughout CBTi. There were no differences in changes in daytime sleepiness during treatment between CBTi and control groups or OSA-severity groups. Higher pretreatment ESS scores were associated with a greater ESS reduction during CBTi.

Conclusions

CBTi appears to be a safe and effective treatment in the presence of comorbid moderate and severe OSA. Nevertheless, patients living with comorbid insomnia and sleep apnea and treated with CBTi should be monitored closely for increased daytime sleepiness during the initial weeks of bedtime restriction therapy.

Clinical Trial Registration

Treating comorbid insomnia with obstructive sleep apnoea (COMISA) study: A new treatment strategy for patients with combined insomnia and sleep apnoea, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id = 365184 Australian New Zealand Clinical Trials Registry: ACTRN12613001178730. Universal Trial Number: U1111-1149-4230.

Sleep Apnea Multilevel Surgery (SAMS) trial protocol: a multicenter randomized clinical trial of upper airway surgery for patients with obstructive sleep apnea who have failed continuous positive airway pressure

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is a serious and costly public health problem. The main medical treatment, continuous positive airway pressure, is efficacious when used, but poorly tolerated in up to 50% of patients. Upper airway reconstructive surgery is available when medical treatments fail but randomized trial evidence supporting its use is limited. This protocol details a randomized controlled trial designed to assess the clinical effectiveness, safety, and cost-effectiveness of a multilevel upper airway surgical procedure for OSA.

METHODS

A prospective, parallel-group, open label, randomized, controlled, multicenter clinical trial in adults with moderate or severe OSA who have failed or refused medical therapies. Six clinical sites in Australia randomly allocated participants in a 1:1 ratio to receive either an upper airway surgical procedure consisting of a modified uvulopalatopharyngoplasty and minimally invasive tongue volume reduction, or to continue with ongoing medical management, and followed them for 6 months.

RESULTS

Primary outcomes: difference between groups in baseline-adjusted 6 month OSA severity (apnea-hypopnea index) and subjective sleepiness (Epworth Sleepiness Scale). Secondary outcomes: other OSA symptoms (e.g. snoring and objective sleepiness), other polysomnography parameters (e.g. arousal index and 4% oxygen desaturation index), quality of life, 24 hr ambulatory blood pressure, adverse events, and adherence to ongoing medical therapies (medical group).

CONCLUSIONS

The Sleep Apnea Multilevel Surgery (SAMS) trial is of global public health importance for testing the effectiveness and safety of a multilevel surgical procedure for patients with OSA who have failed medical treatment.

CLINICAL TRIAL REGISTRATION

Multilevel airway surgery in patients with moderate-severe Obstructive Sleep Apnea (OSA) who have failed medical management to assess change in OSA events and daytime sleepiness. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366019&isReview=true Australian New Zealand Clinical Trials Registry ACTRN12614000338662, prospectively registered on 31 March 2014.

Comparing the Efficacy, Mask Leak, Patient Adherence, and Patient Preference of Three Different CPAP Interfaces to Treat Moderate-Severe Obstructive Sleep Apnea

STUDY OBJECTIVES

To determine if the type of continuous positive airway pressure (CPAP) mask interface influences CPAP treatment efficacy, adherence, side effects, comfort and sleep quality in patients with moderate-severe obstructive sleep apnea (OSA).

METHODS

This took place in a hospital-based tertiary sleep disorders unit. It is a prospective, randomized, crossover trial comparing three CPAP interfaces: nasal mask (NM), nasal mask plus chinstrap (NM-CS) and oronasal mask (ONM) each tried in random order, for 4 weeks. After each 4-week period, patient outcomes were assessed. Participants had a new diagnosis of obstructive sleep apneas. Forty-eight patients with moderate-severe OSA (32 males, mean ± standard deviation apnea-hypopnea index (AHI) 55.6 ± 21.1 events/h, age 54.9 ± 13.1 years, body mass index 35.8 ± 7.2 kg/m²) were randomized. Thirty-five participants completed the full study, with complete data available for 34 patients.

RESULTS

There was no statistically significant difference in CPAP adherence; however, residual AHI was higher with ONM than NM and NM-CS (residual AHI 7.1 ± 7.7, 4.0 ± 3.1, 4.2 ± 3.7 events/h respectively, main effect P = .001). Patient satisfaction and quality of sleep were higher with the NM and NM-CS than the ONM. Fewer leak and mask fit problems were reported with NM (all chi-square P < .05), which patients preferred over the NM-CS and ONM options (n = 22, 9 and 4 respectively, P = .001).

CONCLUSIONS

The CPAP adherence did not differ between the three different mask interfaces but the residual AHI was lower with NM than ONM and patients reported greater mask comfort, better sleep, and overall preference for a NM. A nasal mask with or without chinstrap should be the first choice for patients with OSA referred for CPAP treatment.

CLINICAL TRIAL REGISTRATION

Registry: Australian and New Zealand Clinical Trials Registry, URL: https://www.anzctr.org.au, title: A comparison of continuous positive airway pressure (CPAP) interface in the control of leak, patient compliance and patient preference: nasal CPAP mask and chinstrap versus full face mask in patients with obstructive sleep apnoea (OSA), identifier: ACTRN12609000029291.

Chronic Kidney Disease and Sleep Apnea Association of Kidney Disease With Obstructive Sleep Apnea in a Population Study of Men

Study Objectives

To determine the relationship between obstructive sleep apnea (OSA) and chronic kidney disease (CKD). Previous population studies of the association are sparse, conflicting and confined largely to studies of administrative data.

Methods

Cross-sectional analysis in unselected participants of the Men Androgens Inflammation Lifestyle Environment and Stress (MAILES) study, aged >40 years. Renal data were available for 812 men without a prior OSA diagnosis who underwent full in-home polysomnography (Embletta X100) in 2010-2011. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2 or eGFR≥60 and albuminuria (albumin-creatinine ratio ≥3.0 mg/mmol).

Results

CKD (10.5%, n = 85 [Stage 1-3, 9.7%; Stage 4-5, 0.7%]) of predominantly mild severity showed significant associations with OSA (apnea-hypoapnea index [AHI] ≥ 10): odds ratio (OR) = 1.9, 95% confidence interval (CI): 1.02-3.5; severe OSA (AHI ≥ 30/h): OR = 2.6, 95% CI: 1.1-6.2; and respiratory-related arousal index: ≥7.6/h, OR = 2.3, 95%CI: 1.1-4.7; but not measures of hypoxemia after adjustment for age, hypertension, diabetes, smoking, obesity, and NSAID use. There was no association of CKD with daytime sleepiness. In men with CKD, those with OSA were not significantly more likely to report symptoms (sleepiness, snoring, and apneas) or be identified with the STOP OSA screening questionnaire, compared to men without OSA.

Conclusions

Predominantly mild CKD is associated with severe OSA and arousals. Further population studies examining the longitudinal relationship between CKD and OSA are warranted. Better methods are needed to identify OSA in CKD which may have few symptoms.

Predictors of obstructive sleep apnoea in patients admitted for acute coronary syndrome

Identifying undiagnosed obstructive sleep apnoea (OSA) patients in cardiovascular clinics could improve their management. Aiming to build an OSA predictive model, a broad analysis of clinical variables was performed in a cohort of acute coronary syndrome (ACS) patients.

Sociodemographic, anthropometric, life-style and pharmacological variables were recorded. Clinical measures included blood pressure, electrocardiography, echocardiography, blood count, troponin levels and a metabolic panel. OSA was diagnosed using respiratory polygraphy. Logistic regression models and classification and regression trees were used to create predictive models.

A total of 978 patients were included (298 subjects with apnoea–hypopnoea index (AHI) <15 events·h−1and 680 with AHI ≥15 events·h−1). Age, BMI, Epworth sleepiness scale, peak troponin levels and use of calcium antagonists were the main determinants of AHI ≥15 events·h−1(C statistic 0.71; sensitivity 94%; specificity 24%). Age, BMI, blood triglycerides, peak troponin levels and Killip class ≥II were determinants of AHI ≥30 events·h−1(C statistic of 0.67; sensitivity 31%; specificity 86%).

Although a set of variables associated with OSA was identified, no model could successfully predict OSA in patients admitted for ACS. Given the high prevalence of OSA, the authors propose respiratory polygraphy as a to-be-explored strategy to identify OSA in ACS patients.

Physician Decision Making and Clinical Outcomes With Laboratory Polysomnography or Limited-Channel Sleep Studies for Obstructive Sleep Apnea: A Randomized Trial

BACKGROUND

The clinical utility of limited-channel sleep studies (which are increasingly conducted at home) versus laboratory polysomnography (PSG) for diagnosing obstructive sleep apnea (OSA) is unclear.

OBJECTIVE

To compare patient outcomes after PSG versus limited-channel studies.

DESIGN

Multicenter, randomized, noninferiority study. (Australian New Zealand Clinical Trials Registry: ACTRN12611000926932).

SETTING

7 academic sleep centers.

PARTICIPANTS

Patients (n = 406) aged 25 to 80 years with suspected OSA.

INTERVENTION

Sleep study information disclosed to sleep physicians comprised level 1 (L1) PSG data (n = 135); level 3 (L3), which included airflow, thoracoabdominal bands, body position, electrocardiography, and oxygen saturation (n = 136); or level 4 (L4), which included oxygen saturation and heart rate (n = 135).

MEASUREMENTS

The primary outcome was change in Functional Outcomes of Sleep Questionnaire (FOSQ) score at 4 months. Secondary outcomes included the Epworth Sleepiness Scale (ESS), the Sleep Apnea Symptoms Questionnaire (SASQ), continuous positive airway pressure (CPAP) compliance, and physician decision making.

RESULTS

Change in FOSQ score was not inferior for L3 (mean difference [MD], 0.01 [95% CI, -0.47 to 0.49; P = 0.96]) or L4 (MD, -0.46 [CI, -0.94 to 0.02; P = 0.058]) versus L1 (noninferiority margin [NIM], -1.0). Compared with L1, change in ESS score was not inferior for L3 (MD, 0.08 [CI, -0.98 to 1.13; P = 0.89]) but was inconclusive for L4 (MD, 1.30 [CI, 0.26 to 2.35; P = 0.015]) (NIM, 2.0). For L4 versus L1, there was less improvement in SASQ score (-17.8 vs. -24.7; P = 0.018), less CPAP use (4.5 vs. 5.3 hours per night; P = 0.04), and lower physician diagnostic confidence (P = 0.003).

LIMITATION

Limited-channel studies were simulated by extracting laboratory PSG data and were not done in the home.

CONCLUSION

The results support manually scored L3 testing in routine practice. Poorer outcomes with L4 testing may relate, in part, to reduced physician confidence.

PRIMARY FUNDING SOURCE

National Health and Medical Research Council and Repat Foundation.

CPAP for Prevention of Cardiovascular Events in Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea is associated with an increased risk of cardiovascular events; whether treatment with continuous positive airway pressure (CPAP) prevents major cardiovascular events is uncertain.

METHODS

After a 1-week run-in period during which the participants used sham CPAP, we randomly assigned 2717 eligible adults between 45 and 75 years of age who had moderate-to-severe obstructive sleep apnea and coronary or cerebrovascular disease to receive CPAP treatment plus usual care (CPAP group) or usual care alone (usual-care group). The primary composite end point was death from cardiovascular causes, myocardial infarction, stroke, or hospitalization for unstable angina, heart failure, or transient ischemic attack. Secondary end points included other cardiovascular outcomes, health-related quality of life, snoring symptoms, daytime sleepiness, and mood.

RESULTS

Most of the participants were men who had moderate-to-severe obstructive sleep apnea and minimal sleepiness. In the CPAP group, the mean duration of adherence to CPAP therapy was 3.3 hours per night, and the mean apnea-hypopnea index (the number of apnea or hypopnea events per hour of recording) decreased from 29.0 events per hour at baseline to 3.7 events per hour during follow-up. After a mean follow-up of 3.7 years, a primary end-point event had occurred in 229 participants in the CPAP group (17.0%) and in 207 participants in the usual-care group (15.4%) (hazard ratio with CPAP, 1.10; 95% confidence interval, 0.91 to 1.32; P=0.34). No significant effect on any individual or other composite cardiovascular end point was observed. CPAP significantly reduced snoring and daytime sleepiness and improved health-related quality of life and mood.

CONCLUSIONS

Therapy with CPAP plus usual care, as compared with usual care alone, did not prevent cardiovascular events in patients with moderate-to-severe obstructive sleep apnea and established cardiovascular disease. (Funded by the National Health and Medical Research Council of Australia and others; SAVE ClinicalTrials.gov number, NCT00738179 ; Australian New Zealand Clinical Trials Registry number, ACTRN12608000409370 .).

A novel sleep optimisation programme to improve athletes' well-being and performance

OBJECTIVES

To improve well-being and performance indicators in a group of Australian Football League (AFL) players via a six-week sleep optimisation programme.

DESIGN

Prospective intervention study following observations suggestive of reduced sleep and excessive daytime sleepiness in an AFL group.

METHODS

Athletes from the Adelaide Football Club were invited to participate if they had played AFL senior-level football for 1-5 years, or if they had excessive daytime sleepiness (Epworth Sleepiness Scale [ESS] >10), measured via ESS. An initial education session explained normal sleep needs, and how to achieve increased sleep duration and quality. Participants (n = 25) received ongoing feedback on their sleep, and a mid-programme education and feedback session. Sleep duration, quality and related outcomes were measured during week one and at the conclusion of the six-week intervention period using sleep diaries, actigraphy, ESS, Pittsburgh Sleep Quality Index, Profile of Mood States, Training Distress Scale, Perceived Stress Scale and the Psychomotor Vigilance Task.

RESULTS

Sleep diaries demonstrated an increase in total sleep time of approximately 20 min (498.8 ± 53.8 to 518.7 ± 34.3; p < .05) and a 2% increase in sleep efficiency (p < 0.05). There was a corresponding increase in vigour (p < 0.001) and decrease in fatigue (p < 0.05).

CONCLUSIONS

Improvements in measures of sleep efficiency, fatigue and vigour indicate that a sleep optimisation programme may improve athletes' well-being. More research is required into the effects of sleep optimisation on athletic performance.

The association of obstructive sleep apnea (OSA) and nocturnal hypoxemia with the development of abnormal HbA1c in a population cohort of men without diabetes

AIM

To examine the relationship between indices of undiagnosed OSA and the development of abnormal glycaemic control in community-dwelling men free of diabetes.

METHODS

The Men, Androgens, Inflammation, Lifestyle, Environment, and Stress (MAILES) Study is a population-based cohort study in Adelaide, South Australia. Clinic visits at baseline (2002-06) and follow-up (2007-10) identified abnormal glycaemic metabolism [HbA1c 6.0 to <6.5% (42 to <48mmol/mol)] in men without diabetes. At follow-up (2010-11), n=837 underwent assessment of OSA by full in-home unattended polysomnography (Embletta X100).

RESULTS

Development of abnormal glycaemic metabolism over 4-6 years (n=103 "incident" cases, 17.0%) showed adjusted associations [odds ratio (95% CI)] with the 1st [1.7 (0.8-3.8)], 2nd [2.4 (1.1-4.9)], and 3rd [2.3 (1.1-4.8)] quartiles of mean oxygen saturation (SaO2) compared to the highest quartile. Prevalent abnormal glycaemic metabolism (n=140, 20.8%) was independently associated with the third and fourth quartiles of percentage of sleep time with oxygen saturation <90% and lowest quartile of mean SaO2. Linear regression analysis showed a significant reduction in HbA1c [unstandardized B, 95% CI: -0.02 (-0.04, -0.002), p=0.034] per percentage point increase in mean SaO2. OSA as measured by the apnea-hypopnea index showed no adjusted relationship with abnormal glycaemic metabolism.

CONCLUSIONS

Development of abnormal glycaemic metabolism was associated with nocturnal hypoxemia. Improved management of OSA and glycaemic control may occur if patients presenting with one abnormality are assessed for the other.

Hypertension Is Associated With Undiagnosed OSA During Rapid Eye Movement Sleep

BACKGROUND

Evidence linking OSA with hypertension in population studies is conflicting. We examined longitudinal and cross-sectional associations of previously unrecognized OSA, including OSA occurring in rapid eye movement (REM) sleep, with hypertension.

METHODS

The Men Androgens Inflammation Lifestyle Environment and Stress (MAILES) study is a longitudinal study of community-dwelling men in Adelaide, South Australia. Biomedical assessments at baseline (2002-2006) and follow-up (2007-2010) identified hypertension (systolic ≥ 140 mm Hg and/or diastolic ≥ 90 mm Hg, or medication) and risk factors. In 2010 to 2011, 837 men without a prior diagnosis of OSA underwent full in-home unattended polysomnography of whom 739 recorded ≥ 30 min of REM sleep. Hypertension at follow-up (concomitant with OSA status) was defined as prevalent hypertension. Recent-onset hypertension was defined as hypertension at biomedical follow-up (56 months mean follow-up [range, 48-74]) in men free of hypertension at baseline.

RESULTS

Severe REM OSA (apnea hypopnea index ≥30/h) showed independent adjusted associations with prevalent (OR, 2.40, 95% CI, 1.42-4.06), and recent-onset hypertension (2.24 [1.04-4.81]). Significant associations with non-REM AHI were not seen. In men with AHI < 10, REM OSA (apnea hypopnea index) ≥ 20/h was significantly associated with prevalent hypertension (2.67 [1.33-5.38]) and the relationship with recent-onset hypertension was positive but not statistically significant (2.32 [0.79-6.84]). Similar results were seen when analyses were confined to men with non-REM AHI < 10.

CONCLUSIONS

In men not considered to have OSA (AHI < 10), hypertension was associated with OSA during REM sleep. REM OSA may need consideration as an important clinical entity requiring treatment but further systematic assessment and evidence is needed.

Self-Reporting by Unsafe Drivers Is, with Education, More Effective than Mandatory Reporting by Doctors

STUDY OBJECTIVES

Health professionals are frequently required to report to relevant authorities all drivers who are potentially unsafe due to medical conditions. We aimed to assess both the effect of mandatory reporting (MR) on patient self-predicted behavior and what factors might encourage unsafe drivers to self-report to these authorities.

METHODS

We included 5 questions in the South Australian Health Omnibus Survey, an annual, community based, face-to-face survey. We asked (1) how subjects would behave towards their doctor in light of MR if they believed their licences were at risk due to a medical condition; and (2) which factor(s) would cause them to self-report to the same authorities.

RESULTS

Responses to 3,007 surveys (response rate 68.5%, age 15-98) showed that 9.0% would avoid diagnosis, lie to their doctor, or doctor shop in order to keep their licence; 30.8% were unaware of the legislated requirement to self-report; and 37.9% were unaware of potentially jeopardizing insurance support if they failed to comply. If educated in these 2 areas, warned about the dangers of driving against medical advice and instructed to do so by their doctor, then 95.8% of people would self-report to the authorities, a number significantly higher than could be reported by their doctors (91.0%).

CONCLUSIONS

MR causes 9.0% of people to predict to behave towards their doctor in a manner that reduces road safety. With education and encouragement to do so, more people will self-report to the authorities than could be reported by their doctors via the MR pathway.

COMMENTARY

A commentary on this article appears in this issue on page 287.

Statistical analysis plan for the Sleep Apnea cardioVascular Endpoints study: An international randomised controlled trial to determine whether continuous positive airways pressure treatment for obstructive sleep apnea in patients with CV disease prevents secondary cardiovascular events

RATIONALE

Obstructive sleep apnea (OSA) is associated with increased risk of cardiovascular disease. Continuous positive airway pressure (CPAP) delivered via a nasal mask during sleep immediately alleviates obstructive apneas and improves sleep quality and daytime somnolence. However, there is uncertainty as to whether such treatment can modify CV risk and disease.

AIMS

The Sleep Apnea Cardiovascular Endpoints (SAVE) study aims to determine whether CPAP on top of best medical care compared to best medical care alone can reduce the risk of serious CV events in patients with co-morbid OSA and established CV disease.

DESIGN

SAVE is an investigator initiated and conducted, international, multicenter, open, blinded endpoint, randomized controlled trial. Participants were randomised to either CPAP or usual care between 2008 and 2013 and will be followed up for an average of approximately 4 years.

STUDY OUTCOME

The primary endpoint is a composite of CV death, myocardial infarction (MI, including silent MI), stroke, hospitalisation for heart failure, hospitalisation for an acute ischemic cardiac event (unstable angina) or cerebral event (transient ischemic event [TIA]).

DISCUSSION

The pre-specified statistical analysis plan (SAP) for the main analyses is presented. This SAP was finalised before patient follow-up was completed and before any unblinding of the data. The SAP outlines details of the primary, secondary and tertiary outcomes, together with planned subgroup and exploratory analyses.

Obstructive sleep apnea and schizophrenia: A systematic review to inform clinical practice

BACKGROUND

Risk factors for obstructive sleep apnea (OSA) are common in people with schizophrenia. Identification and treatment of OSA may improve physical health in this population; however there are no guidelines to inform screening and management.

OBJECTIVES

Systematic review to determine, in people with schizophrenia and related disorders: the prevalence of OSA; the prevalence of OSA compared to general population controls; the physical and psychiatric correlates of OSA, associations between antipsychotic medications and OSA; the impact of treatment of OSA on psychiatric and physical health; and the diagnostic validity of OSA screening tools.

DATA SOURCES

Medline, EMBASE, ISI Web of Science and PsycINFO electronic databases. Cohort, case-control and cross-sectional studies and RCTs reporting on prevalence of OSA in subjects with schizophrenia and related disorders were reviewed.

RESULTS

The prevalence of OSA varied between 1.6% and 52%. The prevalence of OSA was similar between people with schizophrenia and population controls in two studies. Diagnosis of OSA was associated with larger neck circumference, BMI>25, male sex and age>50years. There were no data on physical or psychiatric outcomes following treatment of OSA. The diagnostic utility of OSA screening tools had not been investigated.

CONCLUSION

OSA may be prevalent and potentially under-recognized in people with schizophrenia. Further research is required to determine utility of OSA screening tools, the relationships between antipsychotic medications and OSA and any benefits of treating OSA. We propose a strategy for the identification of OSA in people with schizophrenia and related disorders.

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

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.

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

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.

Individual variability and predictors of driving simulator impairment in patients with obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with driving impairment and road crashes. However, daytime function varies widely between patients presenting a clinical challenge when assessing crash risk. This study aimed to determine the proportion of patients showing "normal" versus "abnormal" driving simulator performance and examine whether anthropometric, clinical, and neurobehavioral measures predict abnormal driving.

METHODS

Thirty-eight OSA patients performed a 90-min simulated driving task under 3 conditions: normal sleep, restricted sleep (4 h in bed), and normal sleep + alcohol (BAC∼0.05 g/dL). Patients were classified as "resilient" drivers if, under all 3 experimental conditions their mean steering deviation fell within 2 standard deviations of the mean steering deviation of 20 controls driving under baseline normal sleep conditions, or a "vulnerable" driver if mean steering deviation was outside this range in at least one experimental condition. Potentially predictive baseline anthropometric, clinical, neurocognitive, and cortical activation measures were examined.

RESULTS

Of the 38 OSA patients examined, 23 (61%) and 15 (39%) were classified as resilient and vulnerable drivers, respectively. There were no differences in baseline measures between the groups, although the proportion of females was greater and self-reported weekly driving exposure was less among vulnerable drivers (p < 0.05). On univariate analysis gender, weekly driving hours, and auditory event related potential P2 amplitude were weakly associated with group status. Multivariate analysis showed weekly driving hours (OR 0.69, 95%CI, 0.51-0.94, p = 0.02) and P2 amplitude (OR 1.34, 95%CI 1.02-1.76, p = 0.035) independently predicted vulnerable drivers.

CONCLUSIONS

Most OSA patients demonstrated normal simulated driving performance despite exposure to further sleep loss or alcohol. Most baseline measures did not differentiate between resilient and vulnerable drivers, although prior driving experience and cortical function were predictive. Novel measures to assist identification of OSA patients at risk of driving impairment and possibly accidents are needed.

TRIAL REGISTRATION

Data presented in this manuscript was collected as part of a clinical trial "Experimental Investigations of Driving Impairment in Obstructive Sleep Apnea." Trial ID: ACTRN12610000009011, URL: http://www.anzctr.org.au/trial_view.aspx?ID=334979.

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

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.

Predictors of long-term adherence to continuous positive airway pressure therapy in patients with obstructive sleep apnea and cardiovascular disease in the SAVE study

STUDY OBJECTIVES

To determine the clinical variables that best predict long- term continuous positive airway pressure (CPAP) adherence among patients with cardiovascular disease who have obstructive sleep apnea (OSA).

DESIGN

12-mo prospective within-trial observational study.

SETTING

Centers in China, Australia, and New Zealand participating in the Sleep Apnea cardioVascular Endpoints (SAVE) study.

PATIENTS

There were 275 patients age 45-70 y with cardiovascular disease (i.e., previously documented transient ischemic attack, stroke, or coronary artery disease) and OSA (4% oxygen desaturation index (ODI) > 12) who were randomized into the CPAP arm of the SAVE trial prior to July 1, 2010.

METHODS

Age, sex, country of residence, type of cardiovascular disease, baseline ODI, severity of sleepiness, and Hospital Anxiety and Depression Scale (HADS) scores plus CPAP side effects and adherence at 1 mo were entered in univariate analyses in an attempt to identify factors predictive of CPAP adherence at 12 mo. Variables with P < 0.2 were then included in a multivariate analysis using a linear mixed model with sites as a random effect and 12-mo CPAP use as the dependent outcome variable.

MEASUREMENTS AND RESULTS

CPAP adherence at 1, 6, and 12 mo was (mean ± standard deviation) 4.4 ± 2.0, 3.8 ± 2.3, and 3.3 ± 2.4 h/night, respectively. CPAP use at 1 mo (effect estimate ± standard error, 0.65 ± 0.07 per h increase, P < 0.001) and side effects at 1 mo (-0.24 ± 0.092 per additional side effect, P = 0.009) were the only independent predictors of 12- mo CPAP adherence.

CONCLUSION

Continuous positive airway pressure use in patients with coexisting cardiovascular disease and moderate to severe obstructive sleep apnea decreases significantly over 12 months. This decline can be predicted by early patient experiences with continuous positive airway pressure (i.e., adherence and side effects at 1 month), raising the possibility that intensive early interventions could improve long-term continuous positive airway pressure compliance in this patient population.

CLINICAL TRIALS REGISTER

Clinical Trials, http://www.clinicaltrials.gov, NCT00738179.

Primary care vs specialist sleep center management of obstructive sleep apnea and daytime sleepiness and quality of life: a randomized trial

IMPORTANCE

Due to increasing demand for sleep services, there has been growing interest in ambulatory models of care for patients with obstructive sleep apnea. With appropriate training and simplified management tools, primary care physicians are ideally positioned to take on a greater role in diagnosis and treatment.

OBJECTIVE

To compare the clinical efficacy and within-trial costs of a simplified model of diagnosis and care in primary care relative to that in specialist sleep centers.

DESIGN, SETTING, AND PATIENTS

A randomized, controlled, noninferiority study involving 155 patients with obstructive sleep apnea that was treated at primary care practices (n=81) in metropolitan Adelaide, 3 rural regions of South Australia or at a university hospital sleep medicine center in Adelaide, Australia (n = 74), between September 2008 and June 2010.

INTERVENTIONS

Primary care management of obstructive sleep apnea vs usual care in a specialist sleep center; both plans included continuous positive airway pressure, mandibular advancement splints, or conservative measures only.

MAIN OUTCOME AND MEASURES

The primary outcome was 6-month change in Epworth Sleepiness Scale (ESS) score, which ranges from 0 (no daytime sleepiness) to 24 points (high level of daytime sleepiness). The noninferiority margin was -2.0. Secondary outcomes included disease-specific and general quality of life measures, obstructive sleep apnea symptoms, adherence to using continuous positive airway pressure, patient satisfaction, and health care costs.

RESULTS

There were significant improvements in ESS scores from baseline to 6 months in both groups. In the primary care group, the mean baseline score of 12.8 decreased to 7.0 at 6 months (P < .001), and in the specialist group, the score decreased from a mean of 12.5 to 7.0 (P < .001). Primary care management was noninferior to specialist management with a mean change in ESS score of 5.8 vs 5.4 (adjusted difference, -0.13; lower bound of 1-sided 95% CI, -1.5; P = .43). There were no differences in secondary outcome measures between groups. Seventeen patients (21%) withdrew from the study in the primary care group vs 6 patients (8%) in the specialist group.

CONCLUSIONS AND RELEVANCE

Among patients with obstructive sleep apnea, treatment under a primary care model compared with a specialist model did not result in worse sleepiness scores, suggesting that the 2 treatment modes may be comparable. TRIAL REGISTRATION anzctr.org.au Identifier: ACTRN12608000514303.

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 long-term management of OSA requires careful patient education, enlistment of the family's support and the adoption of self-management and patient goal-setting principles.

The sleep apnea cardiovascular endpoints (SAVE) trial: Rationale and start-up phase

THE SLEEP APNEA CARDIOVASCULAR ENDPOINTS (SAVE) STUDY (CLINICAL TRIALS REGISTRATION NUMBER: NCT00738170) is an academic initiated and conducted, multinational, open, blinded endpoint, randomised controlled trial designed to determine whether treatment of obstructive sleep apnea (OSA) with continuous positive airways pressure (CPAP) can reduce the incidence of serious cardiovascular events in patients with established cardiovascular disease. The answer to this question is of major importance to populations undergoing ageing and lifestyle changes all over the world. The SAVE study brings together respiratory, sleep and cardiovascular clinician-scientists in a unique interdisciplinary collaborative effort with industry sponsors to conduct the largest and most ambitious clinical trial yet conducted in the field of sleep apnea, with a global recruitment target of 5000 patients. Following its launch in Australia and China in late 2008, SAVE has now entered a phase of international expansion with new recruitment networks being established in New Zealand, India and Latin America. This article describes the rationale for the SAVE study, the considerations behind its design, and progress thus far in establishing the recruitment network. The report emphasises the important role that Chinese sleep and cardiovascular investigators have played in the start-up phase of this landmark international project.

What is "success" following surgery for obstructive sleep apnea? The effect of different polysomnographic scoring systems

OBJECTIVES/HYPOTHESIS

To illustrate that the diagnosis of obstructive sleep apnea (OSA) is dependent on the polysomnographic scoring criteria used, and the success rates of treatments for OSA are dependent on the defined outcome measures.

STUDY DESIGN

Retrospective case series with prospective reanalysis of polysomnographic data.

METHODS

Consecutively treated adult patients (N = 40) with moderate to severe OSA having multilevel pharyngeal surgery in 2007 were studied. All patients underwent submucosal lingualplasty and concurrent or previous uvulopalatopharyngoplasty ± palatal advancement. Full polysomnography (PSG) was performed preoperatively and at a mean of 145 days postoperatively. Pre- and postoperative PSG data were analyzed by two different but widely used scoring systems for the apnea-hypopnea index (AHI): The American Academy of Sleep Medicine (AASM) 1999 Chicago criteria and the AASM 2007 recommended criteria.

RESULTS

Follow-up PSG data were available in 31 of 40 patients. Successful surgery was defined as a reduction in AHI(Rec) <20 with a 50% reduction from the patient's baseline, and in this group the surgical intervention was associated with a 72.2% success rate. If, however, differing AHI metrics are used or the absolute or percent reduction used to define a successful outcome is changed, then the rate of surgical success is shown to range from 39% to 92%.

CONCLUSIONS

Different criteria for measuring AHI and defining success following OSA surgery can produce widely conflicting outcome data. Reported results following OSA surgery should be interpreted with this in mind. Using acceptable criteria, multilevel sleep surgery can be demonstrated to be of benefit to the majority of carefully selected patients.

Accurate position monitoring and improved supine-dependent obstructive sleep apnea with a new position recording and supine avoidance device

STUDY OBJECTIVES

Approximately 30% of obstructive sleep apnea (OSA) patients have supine-predominant OSA, and simply avoiding supine sleep should normalise respiratory disturbance event rates. However, traditional supine-avoidance therapies are inherently uncomfortable, and treatment adherence is poor and difficult to monitor objectively. This study evaluated the efficacy of a novel, potentially more acceptable position monitor and supine-avoidance device for managing supine-predominant OSA and snoring.

DESIGN AND SETTING

In-laboratory evaluation of position recording accuracy versus video recordings (validation study), and randomized controlled crossover trial of active versus inactive supine-avoidance therapy in the home setting (efficacy study).

PATIENTS

17 patients undergoing in-laboratory sleep studies (validation) and 15 patients with supine-predominant OSA (efficacy).

INTERVENTIONS

EFFICACY STUDY: 1 week of inactive and 1 week of active treatment in randomized order, separated by 1 week.

MEASUREMENTS AND RESULTS

Agreement between 30-sec epoch-based posture classifications from device versus video records was high (median κ 0.95, interquartile range: 0.88-1.00), and there was good supine time agreement (bias 0.3%, 95%CI: -4.0% to 4.6%). In the efficacy study, apnea-hypopnea index (AHI) and snoring frequency were measured in-home using a nasal pressure and microphone based system during inactive and active treatment weeks. The position monitoring and supine alarm device markedly inhibited supine time (mean ± SEM 19.3% ± 4.3% to 0.4% ± 0.3%, p < 0.001) and reduced AHI (25.0 ± 1.7 to 13.7 ± 1.1 events/h, p = 0.030) but not snoring frequency.

CONCLUSIONS

This new position monitoring and supine alarm device records sleep position accurately and improves OSA but not snoring in patients with supine-predominant OSA.

Treating obstructive sleep apnea with hypoglossal nerve stimulation

BACKGROUND

Reduced upper airway muscle activity during sleep is fundamental to obstructive sleep apnea (OSA) pathogenesis. Hypoglossal nerve stimulation (HGNS) counteracts this problem, with potential to reduce OSA severity.

STUDY OBJECTIVES

To examine safety and efficacy of a novel HGNS system (HGNS, Apnex Medical, Inc.) in treating OSA.

PARTICIPANTS

Twenty-one patients, 67% male, age (mean ± SD) 53.6 ± 9.2 years, with moderate to severe OSA and unable to tolerate continuous positive airway pressure (CPAP).

DESIGN

Each participant underwent surgical implantation of the HGNS system in a prospective single-arm interventional trial. OSA severity was defined by apnea-hypopnea index (AHI) during in-laboratory polysomnography (PSG) at baseline and 3 and 6 months post-implant. Therapy compliance was assessed by nightly hours of use. Symptoms were assessed using the Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), Calgary Sleep Apnea Quality of Life Index (SAQLI), and the Beck Depression Inventory (BDI).

RESULTS

HGNS was used on 89% ± 15% of nights (n = 21). On these nights, it was used for 5.8 ± 1.6 h per night. Nineteen of 21 participants had baseline and 6-month PSGs. There was a significant improvement (all P < 0.05) from baseline to 6 months in: AHI (43.1 ± 17.5 to 19.5 ± 16.7), ESS (12.1 ± 4.7 to 8.1 ± 4.4), FOSQ (14.4 ± 2.0 to 16.7 ± 2.2), SAQLI (3.2 ± 1.0 to 4.9 ± 1.3), and BDI (15.8 ± 9.0 to 9.7 ± 7.6). Two serious device-related adverse events occurred: an infection requiring device removal and a stimulation lead cuff dislodgement requiring replacement.

CONCLUSIONS

HGNS demonstrated favorable safety, efficacy, and compliance. Participants experienced a significant decrease in OSA severity and OSA-associated symptoms.

CLINICAL TRIAL INFORMATION

NAME: Australian Clinical Study of the Apnex Medical HGNS System to Treat Obstructive Sleep Apnea.

REGISTRATION NUMBER

NCT01186926. URL: http://clinicaltrials.gov/ct2/show/NCT01186926.

Auditory evoked potentials remain abnormal after CPAP treatment in patients with severe obstructive sleep apnoea

OBJECTIVE

To assess the effects of 3 months of optimal CPAP treatment on auditory event related potentials (AERP) in patients with severe obstructive sleep apnoea (OSA) compared with healthy controls.

METHODS

Auditory odd-ball related N1, P2, N2 and P3 AERP components were assessed in 9 severe OSA subjects and 9 healthy controls at baseline evaluation and at ∼3 months follow-up in both groups, with OSA subjects treated with continuous positive air-way pressure (CPAP) during this period.

RESULTS

Severe OSA subjects showed significantly delayed, P2, N2 and P3 latencies, and significantly different P2 and P3 amplitudes compared to controls at baseline (group effect, all p<0.05). At follow-up evaluation P3 latency shortened in treated OSA patients but remained prolonged compared to controls (group by treatment interaction, p<0.05) despite high CPAP compliance (6h/night). The earlier AERP (P2 and N2) components did not change in either controls or OSA patients at follow-up and remained different in patients versus controls.

CONCLUSIONS

This study demonstrates that in severe OSA patients AERP responses show minimal or no improvement and remain abnormal following 3 months of optimal CPAP treatment.

SIGNIFICANCE

Persistent cortical sensory processing abnormalities despite treatment in severe OSA may have implications for daytime neurobehavioral performance and safety in OSA patients. AERP responses may help identify residual performance deficits and risks.

Driving simulator performance remains impaired in patients with severe OSA after CPAP treatment

STUDY OBJECTIVES

To assess the effectiveness of CPAP treatment in improving 90-minute driving simulator performance in severe OSA patients compared to age/gender matched controls.

DESIGN

Driving simulator performance was assessed at baseline and 3 months later, with OSA patients treated with CPAP during the interval.

SETTING

University Teaching Hospital.

PARTICIPANTS

Patients with severe OSA (n = 11) and control subjects without OSA (n = 9).

INTERVENTIONS

CPAP MEASUREMENTS AND RESULTS: Simulator driving parameters of steering deviation, braking reaction time and crashes were measured at baseline and ∼3 months follow-up. At baseline, OSA subjects demonstrated significantly greater steering deviation compared to controls (mean [95% CI], OSA group, 49.9 cm [43.7 to 56.0 cm] vs control group, 34.9 cm [28.1 to 41.7 cm], p = 0.003). Following ∼3 months of CPAP treatment (mean ± SD 6.0 ± 1.4 h/night), steering deviation in OSA subjects improved by an average of 3.1 cm (CI, 1.4 to 4.9), p < 0.001, while no significant steering changes were observed in the control group. Despite the improvement, steering deviation in the OSA group remained significantly higher than in controls (OSA group, 46.7 cm [CI, 40.6 to 52.8 cm] vs control group, 36.1 cm [CI, 29.3 to 42.9 cm], p = 0.025).

CONCLUSIONS

While driving simulator performance improved after ∼3 months of CPAP treatment with high adherence in patients with severe OSA, performance remained impaired compared to control subjects. These results add to the growing body of evidence that some neurobehavioral deficits in patients with severe OSA are not fully reversed by treatment. Further studies are needed to assess causes of residual driving simulator impairment and to determine whether this is associated with persistent elevated real-life accident risk.

TRIAL REGISTRATION

Data presented in this manuscript was collected as part of a clinical trial "Experimental Investigations of Driving Impairment in Obstructive Sleep Apnoea" ACTRN12610000009011, http://www.anzctr.org.au/trial_view.aspx?ID=334979

The effect of CPAP in normalizing daytime sleepiness, quality of life, and neurocognitive function in patients with moderate to severe OSA

STUDY OBJECTIVES

The study aimed to document the neurobehavioral outcomes of patients referred to and treated by a sleep medicine service for moderate to severe obstructive sleep apnea (OSA). In particular, we aimed to establish the proportion of patients who, while appearing to have optimal continuous positive airway pressure (CPAP) adherence, did not normalize their daytime sleepiness or neurocognitive function after 3 months of CPAP therapy despite effective control of OSA.

DESIGN

Multicenter clinical-effectiveness study.

SETTING

Three academic sleep centers in Australia.

PARTICIPANTS

Patients referred to a sleep medicine service with moderate to severe OSA (n = 174).

INTERVENTION

CPAP.

MEASUREMENTS AND RESULTS

Participants were assessed pretreatment and again after 3 months of CPAP therapy. At the beginning and at the conclusion of the trial, participants completed a day of testing that included measures of objective and subjective daytime sleepiness, neurocognitive function, and quality of life. In patients with symptomatic moderate to severe OSA (i.e., apnea-hypopnea index > 30/h), we found a treatment dose-response effect for CPAP in terms of Epworth Sleepiness Scale scores (P < 0.001). Several key indexes of neurobehavior (e.g., Functional Outcomes of Sleep Questionnaire, Epworth Sleepiness Scale) currently used to assess treatment response failed to normalize in a substantial group of patients after 3 months of CPAP treatment, even in those who were maximally compliant with treatment. Forty percent of patients in this trial had an abnormal Epworth Sleepiness Scale score at the conclusion of the trial. In addition, we showed no dose-response effect with the Maintenance of Wakefulness Test, raising doubts as to the clinical utility of the Maintenance of Wakefulness Test in assessing treatment response to CPAP in patients with OSA.

CONCLUSIONS

Our study suggests that a greater percentage of patients achieve normal functioning with longer nightly CPAP duration of use, but a substantial proportion of patients will not normalize neurobehavioral responses despite seemingly adequate CPAP use. It is thus crucial to adequately assess patients after CPAP therapy and seek alternate etiologies and treatments for any residual abnormalities.

Obstructive Sleep Apnoea: From pathogenesis to treatment: Current controversies and future directions

Obstructive sleep apnoea (OSA) is a common disease, recognized as an independent risk factor for a range of clinical conditions, such as hypertension, stroke, depression and diabetes. Despite extensive research over the past two decades, the mechanistic links between OSA and other associated clinical conditions, including metabolic disorders and cardiovascular disease, remain unclear. Indeed, the pathogenesis of OSA itself remains incompletely understood. This review provides opinions from a number of leading experts on issues related to OSA and its pathogenesis, interaction with anaesthesia, metabolic consequences and comorbidities, cardiovascular disease, genetics, measurement and diagnosis, surgical treatment and pharmacotherapeutic targets.