The Role of Weight Management in the Treatment of Adult Obstructive Sleep Apnea. An Official American Thoracic Society Clinical Practice Guideline.

BACKGROUND: Overweight/obesity is a common, reversible risk factor for obstructive sleep apnea severity (OSA). The purpose of this guideline is to provide evidence-based recommendations for the management of overweight/obesity in patients with OSA. METHODS: The Grading of Recommendations, Assessment, Development and Evaluation approach was used to evaluate the literature. Clinical recommendations were formulated by a panel of pulmonary, sleep medicine, weight management, and behavioral science specialists. RESULTS: Behavioral, pharmacological, and surgical treatments promote weight loss and can reduce OSA severity, reverse common comorbidities, and improve quality of life, although published studies have methodological limitations. After considering the quality of evidence, feasibility, and acceptability of these interventions, the panel made a strong recommendation that patients with OSA who are overweight or obese be treated with comprehensive lifestyle intervention consisting of 1) a reduced-calorie diet, 2) exercise or increased physical activity, and 3) behavioral guidance. Conditional recommendations were made regarding reduced-calorie diet and exercise/increased physical activity as separate management tools. Pharmacological therapy and bariatric surgery are appropriate for selected patients who require further assistance with weight loss. CONCLUSIONS: Weight-loss interventions, especially comprehensive lifestyle interventions, are associated with improvements in OSA severity, cardiometabolic comorbidities, and quality of life. The American Thoracic Society recommends that clinicians regularly assess weight and incorporate weight management strategies that are tailored to individual patient preferences into the routine treatment of adult patients with OSA who are overweight or obese.

Critical review: CPAP and weight management of obstructive sleep apnea cardiovascular co-morbidities.

The cardiovascular co-morbidities of obstructive sleep apnea (OSA) are similar to those of obesity. Cardiovascular co-morbidities often are the cause of adverse outcomes in overweight/obese OSA patients. Continuous positive airway pressure (CPAP) therapy resolves the symptoms of OSA, but may, or may not lead to improvement of a given cardiovascular co-morbidity. The impact of CPAP on cardiovascular risk variables, adverse cardiovascular events in overweight/obese OSA patients has been evaluated primarily in prospective, uncontrolled cohort studies. These studies show improvement in myocardial and endothelial function, blood pressure, left ventricular performance and stroke survival. Randomized controlled studies (RCTs) examining the effect of weight management on cardiovascular risk factors and disease outcomes show that intentional weight loss leads to improvement in cardiovascular risk, hypertension, coronary artery disease, but not in stroke. Weight loss improves mortality in relatively healthy overweight/obese populations, but possibly not in all groups with cardiometabolic diseases. Clinicians caring for overweight/obese OSA patients should consider the advantages of incorporating weight management into their treatment programs for such patients.

Influence of neighbourhood-level crowding on sleep-disordered breathing severity: mediation by body size.

Neighbourhood-level crowding, a measure of the percentage of households with more than one person per room, may impact the severity of sleep-disordered breathing. This study examined the association of neighbourhood-level crowding with apnoea-hypopnoea index in a large clinical sample of diverse adults with sleep-disordered breathing. Sleep-disordered breathing severity was quantified as the apnoea-hypopnoea index calculated from overnight polysomnogram; analyses were restricted to those with apnoea-hypopnoea index ≥5. Neighbourhood-level crowding was defined using 2000 US Census tract data as percentage of households in a census tract with >1 person per room. Multivariable linear mixed models were fit to examine the associations between the percentage of neighbourhood-level crowding and apnoea-hypopnoea index, and a causal mediation analysis was conducted to determine if body mass index acted as a mediator between neighbourhood-level crowding and apnoea-hypopnoea index. Among 1789 patients (43% African American; 68% male; 80% obese), the mean apnoea-hypopnoea index was 29.0 ±â€…25.3. After adjusting for race, age, marital status and gender, neighbourhood-level crowding was associated with apnoea-hypopnoea index; for every one-unit increase in percentage of neighbourhood-level crowding mean, the apnoea-hypopnoea index increased by 0.40 ±â€…0.20 (P = 0.04). There was a statistically significant indirect effect of neighbourhood-level crowding through body mass index on the apnoea-hypopnoea index (P < 0.001). Neighbourhood-level crowding is associated with severity of sleep-disordered breathing. Body mass index partially mediated the association between neighbourhood-level crowding and sleep-disordered breathing. Investigating prevalent neighbourhood conditions impacting breathing in urban settings may be promising.

Assessment of multiple health risks in a single obstructive sleep apnea population.

STUDY OBJECTIVES: In order to provide a comprehensive estimate of the health risks for OSA patients, we analyzed multiple outcomes and independent predictors of these outcomes in an OSA population evaluated and followed at one sleep center. METHODS: Cox proportional hazard regression analyses were used in an 8-year follow-up analysis of consecutive OSA patients (N = 1025) and non-apneic snorers (apnea-hypopnea index < 5, N = 494). RESULTS: In our fully adjusted model, independent variables predictive of all-cause mortality, myocardial infarction, cerebral vascular accident, and pulmonary embolus were: older age, male gender, and history of cardiovascular diseases or procedures. In examining subgroups based on age and gender, severe OSA (AHI ≥ 30) was one of the independent predictors of mortality in males and in patients < 50 years old. Severe OSA interacted with maleness, age, and hypertension to predict mortality and myocardial infarction. CPAP use ≥ 4 h/night was associated with lower mortality rates in males and those ≥ 50 years old with severe OSA. CONCLUSIONS: Mortality and cardiovascular event outcomes were predicted by demographics and cardiovascular disease history more commonly than by OSA severity. OSA severity was an important predictor of mortality in male and young OSA patients. CPAP use appeared protective in older and male severe OSA patients.

Continuous positive airway pressure in severe obstructive sleep apnea reduces pain sensitivity.

STUDY OBJECTIVE: To evaluate effects of CPAP on pain sensitivity in severe OSA patients. DESIGN: Within-subject treatment study. SETTING: Hospital-based sleep disorders center. PATIENTS: Twelve severe OSA patients (7 men, 5 women), 50.2 ± 12.5 years, with no pain. INTERVENTIONS: The morning after a diagnostic nocturnal polysomnogram (NPSG), patients underwent a training session of finger withdrawal latency (FWL) testing to a radiant heat stimulus, a validated human behavioral model of thermal nociception. Baseline FWL in seconds was obtained after the training session. CPAP pressure was titrated on a second night in the laboratory. Two nights after titration, patients returned to sleep in the laboratory on CPAP. FWL was tested in the morning after awakening, after 6-8 wks of CPAP use, and finally (within 6-8 weeks) after 2 nights of discontinuation of CPAP. Mean FWL in seconds (sec) was compared using MANOVAs with nights as the within subject variable. RESULTS: Apnea-hypopnea index (AHI) decreased from 50.9 ± 14.5 to 1.4 ± 1.0 with CPAP, and sleep continuity improved. In parallel, FWL increased significantly from a mean baseline of 9.8 ± 1.3 sec to 13.7 ± 5.1 sec (P = 0.01) and with continued CPAP use (5.1 ± 2.3 h nightly) for 6-8 weeks FWL remained elevated (21.1 ± 16.2 sec). After the 2-night CPAP discontinuation, apnea/hypopneas returned and sleep was fragmented (AHI = 32.6 ± 19.8). FWL decreased to 11.6 ± 5.9 sec relative to intermediate-term CPAP use (P = 0.03). CONCLUSION: CPAP treatment reduces pain sensitivity in OSA patients. Future studies will focus on patients with OSA and chronic pain and identify mediating mechanisms.

Prevalence and polysomnographic correlates of insomnia comorbid with medical disorders.

STUDY OBJECTIVES: To determine the prevalence and polysomnographic correlates of insomnia in subjects with self-reported medical disorders. DESIGN: Prospective cross-sectional study. PARTICIPANTS: Community-based sample of 3282 men and women aged 18 to 65 years old, with a subset who underwent polysomnography. MEASUREMENTS: Self-reported measures of sleep habits and current health, and polysomnographic sleep variables. RESULTS: The prevalence of insomnia was 21.4%. The adjusted odds of insomnia were 2.2 times as high in persons with any medical disorders as in those without medical disorders. Specifically, odds of insomnia were higher in people with heart disease (OR = 1.6 [95% CI: 1.2-23], P = 0.004), hypertension (1.5 [12-18], P < 0.001), diabetes (1.4 [105-20], P = 0.04), stomach ulcers (2.1 [1.6-2.7], P < 0.001), arthritis (1.8 [1.5-2.2], P < 0.001), migraine (1.8 [1.5-2.1], P < 0.001), asthma (1.6 [1.3-2.0], P = 0.04), COPD (1.9 [1.5-2.5], P < 0.001), neurological problems (2.0 [1.5-2.7], P < 0.001), and menstrual problems (1.7 [1.3-2.1], P < 0.001) than in people without these disorders. Prevalence of insomnia increased with increasing number of medical disorders. However, polysomnographic sleep was not significantly different in persons with or without medical disorders for most disorders assessed. CONCLUSION: This large population-based study suggests that insomnia is highly prevalent in diverse chronic medical disorders. However, polysomnographic evidence of disturbed sleep is present in only a subset of comorbid insomnia populations.

Comparative levels of excessive daytime sleepiness in common medical disorders.

INTRODUCTION: Sleep restriction and sleep disorders are common causes of excessive daytime sleepiness (EDS). Medical disorders (MD) can also cause EDS, but previous studies have used non-standardized measures, selected samples, or have examined EDS in singular disorders. This study describes the relative degree of EDS associated with medical disorders to provide comparative data across a range of common medical conditions in a large unselected community-based sample. METHODS: Responses of 2612 individuals (aged 18-65) were assessed after excluding those with suspected sleep disordered breathing, narcolepsy, and shift workers. Participants across a range of medical disorders were evaluated using the Epworth Sleepiness Scale (ESS) and patient reports of nocturnal sleep. RESULTS: Sixty-seven percent of the sample reported a MD. The prevalence of EDS (ESS>or=10) was 31.4% in individuals with MD and increased as a function of a number of MD (0 MD=29.4%, 1 MD=28.4%, 2 MD=31.0%, 3 MD=35.3%, 4 MD=38.4%). Disorders which were independent predictors of EDS were ulcers OR=2.21 (95% CI=1.35-3.61), migraines OR=1.36 (95% CI=1.08-1.72), and depression OR=1.46 (95% CI=1.16-1.83) after controlling for other conditions, age, gender, time in bed, caffeine, smoking and alcohol use. Participants with ulcers had the highest prevalence of sleepiness, 50.0%, as well as the highest level of problems falling asleep (40.8%) and awakenings during the night (62.5%). CONCLUSIONS: Individuals with ulcers, migraines, and depression have independent and clinically significant levels of EDS relative to other common MD.

Improvement of idiopathic central sleep apnea with zolpidem.

STUDY OBJECTIVES: We hypothesized that the non-benzodiazepine hypnotic zolpidem would improve idiopathic central sleep apnea (ICSA) by enhancing sleep stability, resulting in fewer arousals, which in turn would lessen oscillation in arterial CO2 and produce a decrease in central apnea/hypopnea events. Zolpidem might also decrease ventilatory control responsiveness during arousals, thereby reducing hyperpnea, hypocapnia, and subsequent apneas. PATIENTS AND STUDY DESIGN: This was a case series in which all patients with ICSA seen in the Henry Ford Sleep Disorders Clinic from January 1, 2004, to December 31, 2006, were offered zolpidem, as well as other therapeutic options of acetazolamide, continuous positive airway pressure (CPAP), bilevel pressure support, or assist control ventilatory support. Those 20 patients who chose zolpidem were prescribed 10 mg at bedtime. MEASUREMENTS AND RESULTS: After a therapeutic trial averaging 9 weeks, a follow-up polysomnogram showed that the overall apnea/hypopnea index (AHI) and central AHI (CAHI) decreased, 30.0 +/- 18.1 (SD) to 13.5 +/- 13.3 (p = 0.001), and 26.0 +/- 17.2 to 7.1 +/- 11.8 (p < 0.001), respectively, without an overall change in obstructive AHI or arterial oxygen saturation. The total number of arousals per hour decreased with zolpidem use, 24.0 +/- 11.6 to 15.1 +/- 7.7 (p < 0.001), leading to a significant improvement in sleep efficiency. There was a positive correlation between the decrease in CAHI and the arousal index. Consistent with the hypnotic effect of zolpidem, sleep latency decreased, stage 1 sleep percentage decreased, and stage 2 percentage increased (all significant), without changes in stage 3-4 or REM sleep. Excessive daytime sleepiness, measured by the Epworth Sleepiness Scale (ESS) decreased from 13 +/- 5 to 8 +/- 5 (p < 0.001). Three patients experienced a significant increase in obstructive events. CONCLUSION: In an open-label trial, ICSA patients studied experienced a decrease in central apnea/hypopneas with zolpidem. They also had improved sleep continuity and decreased subjective daytime sleepiness, without a worsening of oxygenation or obstructive events in the majority of patients. However, in the absence of a randomized, controlled trial, zolpidem cannot be recommended for treatment of ICSA at this time.

Pain sensitivity in sleepy pain-free normals.

STUDY OBJECTIVE: Past studies have shown that acute experimental reduction of time in bed in otherwise healthy, non-sleepy people leads to hyperalgesia. We hypothesized that otherwise healthy, sleepy people may also exhibit hyperalgesia relative to their non-sleepy counterparts. DESIGN: Between-groups sleep laboratory study. SETTING: Hospital-based sleep disorders center. PARTICIPANTS: Twenty-seven, healthy, normal participants (age 18-35 years) were recruited and categorized into sleepy and non-sleepy groups based on their average sleep latencies on a screening multiple sleep latency test (MSLT). INTERVENTIONS: Both groups were then allowed 8 hours time in bed, following which they underwent pain sensitivity testing (10:30 and 14:30) and sleepiness assessments by the MSLT (10:00, 12:00, 14:00, and 16:00). Pain sensitivity assessments were made by measuring finger withdrawal latencies to a radiant heat source delivering 5 different heat intensities. MEASUREMENTS AND RESULTS: This study showed that after only one night of 8 hours time in bed, the sleepy participants continued to be sleepy and exhibited a more rapid finger withdrawal response (i.e., increased pain sensitivity) to radiant heat than non-sleepy participants. CONCLUSION: This suggests that sleepy individuals experience hyperalgesia in response to a painful stimulus when compared with non-sleepy individuals.

Variables affecting the change in systemic blood pressure in response to nasal CPAP in obstructive sleep apnea patients.

We hypothesized that an improvement in systemic blood pressure (BP) during continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea (OSA) would be related to severity of hypertension (HTN), morphometric parameters such as body mass index, and level of CPAP adherence. We tested this hypothesis with a retrospective review of 85 consecutive OSA patients who had completed diagnostic and CPAP titration polysomnograms and were equipped with a CPAP-adherence monitoring system for a minimum of 1 month of observation. Sphygmomanometer-obtained BP readings were compared at baseline and after 4-6 weeks of CPAP therapy. Presentation BP was significantly and strongly associated with the change in BP seen with treatment. Those with an elevated systolic and diastolic BP and those with an elevation of either systolic or diastolic BP showed a significant fall in BP on CPAP. Those with a BP below the hypertensive range of 140/90 on presentation did not have a significant drop in BP with CPAP. There were no significant changes in systolic, diastolic, or mean BP when patients were categorized by the severity of HTN, as determined by the number of antihypertensive medications prescribed or if they were categorized by the degree of CPAP adherence, objectively determined by the average use of more or less than 4 h/night. We conclude that HTN at initial presentation is among the most important indicators of potential benefit of CPAP administration on BP.

Early CPAP use identifies subsequent adherence to CPAP therapy.

STUDY OBJECTIVES: To explore the relationship between specific factors such as sex and early continuous positive airway pressure (CPAP) use, and 30-day adherence to CPAP therapy. DESIGN AND SETTING: Retrospective study conducted at a single center in southeast Michigan. PATIENTS: One hundred patients with obstructive sleep apnea who were recently initiated on CPAP therapy with electronic adherence information relayed from the CPAP device to a laboratory-based computer through telephone modem. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: An empiric threshold value of objective CPAP use of greater than 4 hours per night measured 3 days following CPAP initiation was predictive of level of CPAP adherence measured 30 days later. Furthermore, CPAP adherence was directly proportional to age (R = 0.25, P = .018). There were no sex-related differences in adherence to CPAP therapy. CONCLUSIONS: Long-term adherence to CPAP therapy can be predicted as early as 3 days following CPAP initiation. The study also demonstrates that younger age and African-American race are independently associated with lower CPAP adherence.

Clinical guidelines for the use of unattended portable monitors in the diagnosis of obstructive sleep apnea in adult patients. Portable Monitoring Task Force of the American Academy of Sleep Medicine.

Based on a review of literature and consensus, the Portable Monitoring Task Force of the American Academy of Sleep Medicine (AASM) makes the following recommendations: unattended portable monitoring (PM) for the diagnosis of obstructive sleep apnea (OSA) should be performed only in conjunction with a comprehensive sleep evaluation. Clinical sleep evaluations using PM must be supervised by a practitioner with board certification in sleep medicine or an individual who fulfills the eligibility criteria for the sleep medicine certification examination. PM may be used as an alternative to polysomnography (PSG) for the diagnosis of OSA in patients with a high pretest probability of moderate to severe OSA. PM is not appropriate for the diagnosis of OSA in patients with significant comorbid medical conditions that may degrade the accuracy of PM. PM is not appropriate for the diagnostic evaluation of patients suspected of having comorbid sleep disorders. PM is not appropriate for general screening of asymptomatic populations. PM may be indicated for the diagnosis of OSA in patients for whom in-laboratory PSG is not possible by virtue of immobility, safety, or critical illness. PM may also be indicated to monitor the response to non-CPAP treatments for sleep apnea. At a minimum, PM must record airflow, respiratory effort, and blood oxygenation. The airflow, effort, and oximetric biosensors conventionally used for in-laboratory PSG should be used in PM. The Task Force recommends that PM testing be performed under the auspices of an AASM-accredited comprehensive sleep medicine program with written policies and procedures. An experienced sleep technologist/technician must apply the sensors or directly educate patients in sensor application. The PM device must allow for display of raw data with the capability of manual scoring or editing of automated scoring by a qualified sleep technician/technologist. A board certified sleep specialist, or an individual who fulfills the eligibility criteria for the sleep medicine certification examination, must review the raw data from PM using scoring criteria consistent with current published AASM standards. Under the conditions specified above, PM may be used for unattended studies in the patient's home. Afollow-up visit to review test results should be performed for all patients undergoing PM. Negative or technically inadequate PM tests in patients with a high pretest probability of moderate to severe OSA should prompt in-laboratory polysomnography.