Weight loss as a treatment for obstructive sleep apnoea

Predicting Obstructive Sleep Apnea Based on Computed Tomography Scans Using Deep Learning Models

Rationale: The incidence of clinically undiagnosed obstructive sleep apnea (OSA) is high among the general population because of limited access to polysomnography. Computed tomography (CT) of craniofacial regions obtained for other purposes can be beneficial in predicting OSA and its severity. Objectives: To predict OSA and its severity based on paranasal CT using a three-dimensional deep learning algorithm. Methods: One internal dataset (N = 798) and two external datasets (N = 135 and N = 85) were used in this study. In the internal dataset, 92 normal participants and 159 with mild, 201 with moderate, and 346 with severe OSA were enrolled to derive the deep learning model. A multimodal deep learning model was elicited from the connection between a three-dimensional convolutional neural network-based part treating unstructured data (CT images) and a multilayer perceptron-based part treating structured data (age, sex, and body mass index) to predict OSA and its severity. Measurements and Main Results: In a four-class classification for predicting the severity of OSA, the AirwayNet-MM-H model (multimodal model with airway-highlighting preprocessing algorithm) showed an average accuracy of 87.6% (95% confidence interval [CI], 86.8-88.6%) in the internal dataset and 84.0% (95% CI, 83.0-85.1%) and 86.3% (95% CI, 85.3-87.3%) in the two external datasets, respectively. In the two-class classification for predicting significant OSA (moderate to severe OSA), the area under the receiver operating characteristic curve, accuracy, sensitivity, specificity, and F1 score were 0.910 (95% CI, 0.899-0.922), 91.0% (95% CI, 90.1-91.9%), 89.9% (95% CI, 88.8-90.9%), 93.5% (95% CI, 92.7-94.3%), and 93.2% (95% CI, 92.5-93.9%), respectively, in the internal dataset. Furthermore, the diagnostic performance of the Airway Net-MM-H model outperformed that of the other six state-of-the-art deep learning models in terms of accuracy for both four- and two-class classifications and area under the receiver operating characteristic curve for two-class classification (P < 0.001). Conclusions: A novel deep learning model, including a multimodal deep learning model and an airway-highlighting preprocessing algorithm from CT images obtained for other purposes, can provide significantly precise outcomes for OSA diagnosis.

Can Weight Loss Improve the Cardiovascular Outcomes of Patients with Obesity and Obstructive Sleep Apnea?

Cardiovascular events are the primary cause of mortality in patients with obstructive sleep apnea and obesity. The rising prevalence of obstructive sleep apnea in recent decades has been linked to increasing rates of obesity. Obstructive sleep apnea has also been linked with many different cardiovascular diseases including coronary artery disease, stroke, heart failure, hypertension, and atrial fibrillation. Obesity is an increasing health concern globally, in part because obesity complications such as hypertension, diabetes, and obstructive sleep apnea increase the risk of cardiovascular diseases. More than 10% weight loss may be required to prevent or reverse obesity complications. Treatment approaches to obesity include nutritional therapy, exercise therapy, pharmacotherapy, and surgical therapies. This review intends to identify the effects of weight loss on cardiovascular outcomes in patients with obesity and obstructive sleep apnea. Despite the strong association between cardiovascular diseases and obstructive sleep apnea, randomized trials have failed to demonstrate that treatment of obstructive sleep apnea reduces cardiovascular events, even in patients with established cardiovascular diseases. Weight loss in patients with obstructive sleep apnea improves HbA1c, systolic blood pressure, HDL cholesterol, and triglycerides, but thus far no changes in cardiovascular events have been shown. The combination of weight loss with continuous positive airway pressure (CPAP) appears more beneficial than either treatment in isolation. Large well-controlled trials in patients with obstructive sleep apnea to assess the effects of different weight reduction programs on cardiovascular disease are still needed.

The evaluation of serum tryptophan and kynurenine levels in patients with obstructive sleep apnea syndrome

PURPOSE

The kynurenine (Kyn) pathway may play a role in certain physiological functions such as behavior, sleep, thermoregulation, and pregnancy. Tryptophan (Trp) is oxidized with tryptophan 2,3-dioxygenase and indolamine 2,3-dioxygenase (IDO). Under normal conditions, hepatic kynurenine is a transcription factor and IDO expression in healthy tissues is very low. The ratio of Kyn to Trp can be used as an indicator to assess IDO activity. This study aimed to determine the relationship between Kyn/Trp ratio and obstructive sleep apnea syndrome (OSAS) disease activity.

METHODS

Study participants were categorized in 3 groups: Group 1 included patients with mild OSAS, Group 2, patients with moderate to severe OSAS, and Group 3, individuals considered normal to serve as controls. The demographic characteristics of the patients were recorded. Apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) measurements were performed by diagnostic polysomnography (PSG). Trp and Kyn levels were determined by HPLC-UV method.

RESULTS

Group 1 included 30 patients (18 men) with mild OSAS; Group 2 included 42 patients (31 men) with moderate to severe OSAS; and Group 3 included 25 controls (13 men). While there was no statistically significant difference between the levels of tryptophan and kynurenine in the groups, a significant difference was found between the Kyn/Trp ratios. A significant correlation was observed in individuals with a body mass index less than 25 with the Kyn/Trp ratio. In individuals with mild OSAS, a significant correlation was observed between ODI and BMI. In individuals with moderate to severe OSAS, there was a significant correlation between ODI, AHI, and BMI.

CONCLUSION

In this study, there was no relationship between OSAS disease severity and IDO activity as assessed by immunoreactivity via the Kyn/Trp pathway.

Role of melanocortin 4 receptor in hypertension induced by chronic intermittent hypoxia

AIM

We previously demonstrated that central nervous system (CNS) melanocortin 4 receptors (MC4R) play a key role in regulating blood pressure (BP) in some conditions associated with increased SNS activity, including obesity. In this study, we examined whether activation of CNS MC4R contributes to chronic intermittent hypoxia (CIH)-induced hypertension and ventilatory responses to hypercapnia.

METHODS

Rats were instrumented with an intracerebroventricular (ICV) cannula in the lateral cerebral ventricle for continuous infusion of MC4R antagonist (SHU-9119) and telemetry probes for measuring mean arterial pressure (MAP) and heart rate (HR). Untreated and SHU-9119-treated rats as well as obese and lean MC4R-deficient rats were exposed to CIH for 7-18 consecutive days.

RESULTS

Chronic intermittent hypoxia reduced cumulative food intake by 18 ± 5 g while MAP and HR increased by 10 ± 3 mm Hg and 9 ± 5 bpm in untreated rats. SHU-9119 increased food intake (from 15 ± 1 to 46 ± 3 g) and prevented CIH-induced reduction in food intake. CIH-induced hypertension was not attenuated by MC4R antagonism (average increase of 10 ± 1 vs 9 ± 1 mm Hg for untreated and SHU-9119 treated rats). In obese MC4R-deficient rats, CIH for 7 days raised BP by 11 ± 4 mm Hg. However, when MC4R-deficient rats were food restricted to prevent obesity, CIH-induced hypertension was attenuated by 32%. We also found that MC4R deficiency was associated with impaired ventilatory responses to hypercapnia independently of obesity.

CONCLUSION

These results show that obesity and the CNS melanocortin system interact in complex ways to elevate BP during CIH and that MC4R may be important in the ventilatory responses to hypercapnia.

Early Onset of Obesity and Adult Onset of Obesity as Factors Affecting Patient Characteristics Prior to Bariatric Surgery

BACKGROUND

Patients who are slated for bariatric surgery vary in terms of their age at onset of obesity, duration of obesity, and their health complications. Therefore, we aimed to explore a relationship between the age at onset of obesity, metabolic parameters, and health problems in bariatric surgery candidates.

METHODS

A total of 469 unrelated adults with obesity prior to bariatric surgery were included in this study. The study group consisted of 246 individuals who became obese < 20 years of age, and 223 individuals who became obese ≥ 20 years. Clinical, biochemical, anthropometric assessments, and DXA-derived measures were taken.

RESULTS

Patients with early onset of obesity had a higher total body fat mass, and higher body fat percentage, and a 1.84 times higher risk of BMI above 40 kg/m2 than patients with adult onset of obesity (≥ 20 years). Multivariable logistic regression demonstrated that, among bariatric surgery candidates with early onset of obesity, the frequency of hypertension and type 2 diabetes was significantly lower than that in cases with an adult onset of obesity, despite a longer duration of obesity and higher BMI.

CONCLUSIONS

The age at which an individual reaches obesity has a significant impact on patient characteristics on the day he or she is evaluated for bariatric surgery. A younger age at obesity onset is a predicting factor for a higher BMI in patients, but they are less likely to clinically manifest well-established consequences of obesity, such as diabetes or hypertension, compared to patients with adult onset of obesity.

Obstructive Sleep Apnea and Neurocognitive Dysfunction in Edentulous Patients

PURPOSE

To record the incidence of cognitive dysfunction in edentulous patients suffering from obstructive sleep apnea (OSA) and establish a plausible hypothesis to explain the correlation of cognitive dysfunction and OSA.

MATERIALS AND METHODS

In this study, 315 edentulous patients (aged 60 to 65 years) visiting the outpatient department at Saraswati Dental College, Lucknow were recruited from January 2013 to October 2015. Prosthodontic Diagnostic Index (PDI) classification was used to assess the intraoral condition to relate it with the span of edentulousness. The BERLIN questionnaire and Epworth Sleepiness Scales were used to diagnose sleep-disordered breathing, following which the patients were put through all-night polysomnography. The apnea-hypopnea index (AHI) scores were derived. Mild and moderate OSA patients were classified into mild, moderate, and severe cognitive dysfunction based on SGRQ-C and SCD. Data were tabulated according to a new classification (Cognitive Dysfunction of Dental Sleep Medicine Patients [CDDSMP] Classification) designed specifically for this study. Data were analyzed using SPSS v15.0. Scores were tabulated as mean ± SD and median [IQR] values. Change from baseline was analyzed using Wilcoxon signed rank test.

RESULTS

Mean scores at different time intervals were 3.03 ± 1.76 (3 months), 2.98 ± 1.80 (6 months), and 2.81 ± 1.84 (9 months). The median [IQR] values of scores at all time intervals except 9 months were 3 [1 to 5]. At 9 months, median [IQR] was 2 [1 to 5]. A significant change in scores was observed in the 3-month interval (p ≤ 0.001).

CONCLUSIONS

The severity of OSA and neurocognitive dysfunction could be directly related to the PDI classification and the span of edentulousness of the patient and modified mandibular advancement device treatment significantly improved the patients' condition, which was reflective from 3 months post-intervention itself.

Prevalence and risk factors of obstructive sleep apnea syndrome in a Saudi Arabian population

BACKGROUND:

Obstructive sleep apnea (OSA) is a common disorder worldwide; however, epidemiological studies on its prevalence lack in Saudi Arabia. This study aimed to determine the prevalence and risk factors of OSA in Saudi Arabia.

METHODS:

The study was performed from 2013 to 2015 in two stages. The screening stage was first; a random sample of Saudi employees (n = 2682) 30–60 years of age completed a survey that included the Wisconsin questionnaire. According to these data, the subjects were categorized as habitual, moderate, or nonsnorers (NSs). The confirmatory second stage was a case–control study conducted on 346 individuals selected from each group using polysomnography (PSG).

RESULTS:

In the first stage, the prevalence of habitual snoring was 23.5%, moderate snoring was16.6%, while 59.9% of the sample was NSs. Among the 346 individuals who underwent PSG, a total of 235 (67.9%) subjects had OSA with an apnea-hypopnea index (AHI) of ≥5; 76 (22.0%) had OSA syndrome (OSAS), defined by an AHI of ≥5 plus daytime sleepiness; and 227 (65.6%) had clinically diagnosed OSA syndrome (COSAS), as defined by the American Academy of Sleep Medicine. A conservative estimate of at least 8.8% (12.8% in men and 5.1% in women) was calculated for the overall prevalence of OSA. Similarly, the overall estimated prevalence of OSAS and COSAS was 2.8% (4.0% in men and 1.8% in women) and 8.5% (12.4% in men and 4.8% in women), respectively. A multivariate analysis revealed age, gender, obesity, and hypertension as independent risk factors of OSA.

CONCLUSIONS:

Our study demonstrated that the rate and risk factors of OSA in the Saudi population are similar to those observed in Western studies.

The relation between sleep and weight in a suburban sleep center: observations and speculations on apnea and weight

STUDY OBJECTIVES

The relationship between obstructive sleep apnea (OSA) and body weight is not clearly established. In order to describe the relationship of weight and OSA severity seen in a suburban sleep center, an observational review was performed of initial diagnostic polysomnograms (PSGs) ordered on patients with American Academy of Sleep Medicine (AASM) symptomatic indications.

METHODOLOGY/PRINCIPLE FINDINGS

Initial, full-night diagnostic or initial split-night (diagnostic portion) PSGs performed for any indication on patients >18 years old were retrospectively reviewed for a two year period. All studies were performed following AASM guidelines. PSG data were reviewed for the presence and severity of apnea (no OSA - apnea hypopnea index (AHI) <5, mild - AHI 5-14, moderate - AHI 15-29, severe - AHI 30-59, and very severe - AHI >60). Data were reviewed from 629 PSGs (37% females and 63% males) of which 450 met the criteria for apnea. Studies were classified by apnea severity (196 mild, 103 moderate, 91 severe apnea and 60 with very severe apnea) and weight (body mass index (BMI)). Of those with apnea, and BMIs <25, severe or very severe apnea occurred in 22% (10/45). Three individuals with BMIs <20 had apnea, one severe. Of those with BMIs ≥40, one (1.6%) did not have apnea and 52% (31/60) had AHI >30.

CONCLUSION/SIGNIFICANCE

The profile of this nonrandom series, tested because they were suspected of having a disorder of sleep, provides guidelines for physicians in their approach to symptomatic patients. Individuals with a normal BMI can have apnea, including severe apnea. Severe obesity (BMI >40) is almost always associated with apnea when symptoms are present. Obesity increases the severity of the diagnosed apnea. Excessive weight should be an indication for testing, but normal weight should not exclude individuals with appropriate symptoms. Obesity, while a major contributing factor to severity, is not the etiological cause of OSA in the majority of these patients.

Obstructive sleep apnea is a common disorder in the population-a review on the epidemiology of sleep apnea

The prevalence of obstructive sleep apnea (OSA) defined at an apnea-hypopnea index (AHI) ≥5 was a mean of 22% (range, 9-37%) in men and 17% (range, 4-50%) in women in eleven published epidemiological studies published between 1993 and 2013. OSA with excessive daytime sleepiness occurred in 6% (range, 3-18%) of men and in 4% (range, 1-17%) of women. The prevalence increased with time and OSA was reported in 37% of men and in 50% of women in studies from 2008 and 2013 respectively. OSA is more prevalent in men than in women and increases with age and obesity. Smoking and alcohol consumption are also suggested as risk factors, but the results are conflicting. Excessive daytime sleepiness is suggested as the most important symptom of OSA, but only a fraction of subjects with AHI >5 report daytime sleepiness and one study did not find any relationship between daytime sleepiness and sleep apnea in women. Stroke and hypertension and coronary artery disease are associated with sleep apnea. Cross-sectional studies indicate an association between OSA and diabetes mellitus. Patients younger than 70 years run an increased risk of early death if they suffer from OSA. It is concluded that OSA is highly prevalent in the population. It is related to age and obesity. Only a part of subjects with OSA in the population have symptoms of daytime sleepiness. The prevalence of OSA has increased in epidemiological studies over time. Differences and the increase in prevalence of sleep apnea are probably due to different diagnostic equipment, definitions, study design and characteristics of included subjects including effects of the obesity epidemic. Cardiovascular disease, especially stroke is related to OSA, and subjects under the age of 70 run an increased risk of early death if they suffer from OSA.

Correlation of cephalometric and anthropometric measures with obstructive sleep apnea severity

Introduction: Patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) often have associated changes in craniofacial morphology and distribution of body fat, either alone or in combination.

Aim: To correlate cephalometric and anthropometric measures with OSAHS severity by using the apnea-hypopnea index (AHI).

Method: A retrospective cephalometry study of 93 patients with OSAHS was conducted from July 2010 to July 2012. The following measurements were evaluated: body mass index (BMI), neck circumference (NC), waist circumference (WC), hip circumference (HC), the angles formed by the cranial base and the maxilla (SNA) and the mandible (SNB), the difference between SNA and SNB (ANB), the distance from the mandibular plane to the hyoid bone (MP-H), the space between the base of the tongue and the posterior pharyngeal wall (PAS), and the distance between the posterior nasal spine and the tip of the uvula (PNS-P). Means, standard deviations, and Pearson's correlation coefficients were calculated and analyzed.

Results: AHI correlated significantly with BMI (r = 0.207, p = 0.047), NC (r = 0.365, p = 0.000), WC (r = 0.337, p = 0.001), PNS-P (r = 0.282, p = 0.006), and MP-H (r = 0.235, p = 0.023).

Conclusion: Anthropometric measurements (BMI, NC, and WC) and cephalometric measurements (MP-H and PNS-P) can be used as predictors of OSAHS severity.

Weight reduction improves sleep, sleepiness and metabolic status in obese sleep apnoea patients

SUMMARY

METHOD

In this prospective intervention study, 33 obese patients with obstructive sleep apnoea syndrome (OSAS) (24 men, 9 women) were consecutively enrolled for a weight reduction program at the Obesity Unit, Karolinska University Hospital. 23 of 33 patients used OSAS-device, 19 with Continuous Positive Airway Pressure and 4 with Mandibular Retaining Device. The patients were investigated with questionnaires, blood tests and ambulant nocturnal polysomnography before and after a 6-month program. Patients with OSAS-device slept without it during the sleep studies. The intervention consisted of 8 weeks low calorie diet and group meetings, followed by a day-care program of behaviour change support.

RESULTS

27 of 33 patients (82%, 21 men and 6 women) completed the study. After the intervention there were highly significant decreases (p < 0.001) in Body Mass Index from mean(S.D.) 40(5) to 34(3), apnoea-hypopnoea index from 43(24) to 26(20) and Epworth Sleepiness Scale (ESS)-score from 9(4) to 6(4). Sleep quality (arousal index, sleep efficiency, percentage deep sleep) and metabolic status (blood pressure, blood glucose levels, lipidemia) were also significantly improved. There was a significant correlation between increased percentage deep sleep and reduced ESS-score. There were no differences due to gender or use/no use of OSAS-device.

CONCLUSION

The results suggest that weight loss, induced by low calorie diet and behaviour change support, significantly improves nocturnal respiratory parameters, sleep quality, daytime sleepiness and metabolic status in obese OSAS patients after 6 months.

Obesity and obstructive sleep apnea--clinical significance of weight loss

Obesity is a major health burden that contributes to increased morbidity and mortality. Obesity is also the most important risk factor for obstructive sleep apnea (OSA); at least 70% of patients are obese. OSA as such, has been linked with increased cardiovascular morbidity and mortality, and OSA patients often display metabolic syndrome. The exact underlying mechanisms behind these associations are complex and not fully understood. In obese individuals, weight reduction and increased physical activity form cornerstones for the prevention and treatment of metabolic syndrome, and recent controlled intervention trials strongly suggest that weight reduction together with a healthy diet and increased physical activity may correct or at least improve the symptoms of OSA. However, regardless of promising results in terms of symptoms of OSA and the undoubted metabolic benefits of changing lifestyles, weight reduction as a treatment of OSA is still underrated by many clinicians. Based on the current knowledge, clinicians should revise their previous attitudes, including suspicions about weight reduction as an effective treatment for OSA patients. Nevertheless, we also need large well-controlled trials on the effects of different weight reduction programs among OSA patients to determine the overall efficacy of different treatment modalities and their long-term success.

The surgical treatment of sleep-related upper airway obstruction

BACKGROUND

Obstructive sleep apnea (OSA) is a very common disorder among adults: the prevalence of mild OSA is 20%, and that of moderate or severe OSA is 6% to 7%. Simple snoring is even more common. Conservative treatments such as nocturnal ventilation therapy and oral appliances are successful as long as the patient actually uses them, but they do not eliminate the underlying obstruction of the upper airway.

METHOD

The relevant literature up to 2008 on the surgical treatment of OSA was selectively reviewed.

RESULTS

Five types of surgical treatment for OSA are available, each for its own indications: optimization of the nasal airway to support nasal ventilation therapy, (adeno-)tonsillectomy as first-line treatment for OSA in children, minimally invasive surgery for simple snoring and mild OSA, invasive surgery as first- and second-line treatment for mild OSA, and invasive multilevel surgery as second-line treatment of moderate to severe OSA that remains refractory to ventilation therapy.

CONCLUSION

Surgical treatment for OSA is appropriate for specific indications as a complement to the established conservative treatment methods.

Maxillary, mandibular and chin advancement surgery for the treatment of obstructive sleep apnoea

The aim of this retrospective study was to determine the effectiveness of maxillary, mandibular and chin advancement (MMCA) surgery as a treatment for obstructive sleep apnoea and to determine the cephalometric parameters of this surgery. Twenty consecutive adult patients with obstructive sleep apnoea for whom other treatments (constant positive airway pressure, mandibular advancement splint and soft tissue surgery) had failed underwent MMCA surgery. Pre- and post-surgical polysomnography studies measuring the Respiratory Disturbance Index (RDI), minimum blood oxygen saturation (MinSaO2) and Epworth Sleepiness Scale (ESS) were compared. Lateral cephalometric radiographs measuring the pre- and post-surgical posterior airway space (PAS) were also analysed. Regression analysis indicated that the change in PAS at the level of B point largely accounted for the change in the RDI, although it was not significantly related with the postoperative oxygen saturation. MMCA surgery was found to be effective as a treatment for obstructive sleep apnoea, and improved all postoperative measures in this study. There was a significant relationship between B point, the PAS and a reduction in RDI.

[Guideline: Treatment of obstructive sleep apnea in adults]

The current guideline discusses conservative and surgical therapy of obstructive sleep apnea (OSA) in adults from the perspective of the ear, nose and throat specialist. The revised guideline was commissioned by the German Society of Ear-Nose-Throat, Head-Neck Surgery (DG HNO KHC) and compiled by the DG HNO KHC's Working Group on Sleep Medicine. The guideline was based on a formal consensus procedure according to the guidelines set out by the German Association of Scientific Medical Societies (AWMF) in the form of a"S2e guideline". Research of the literature available on the subject up to and including December 2008 forms the basis for the recommendations. Evaluation of the publications found was made according to the recommendations of the Oxford Centre for Evidence-Based Medicine (OCEBM). This yielded a recommendation grade, whereby grade A represents highly evidence-based studies and grade D those with a low evidence base.

Obstructive sleep apnea (OSA) and excessive sleepiness associated with OSA: recognition in the primary care setting

Obstructive sleep apnea (OSA) is a common and debilitating condition characterized by recurrent episodes of upper airway obstruction, resulting in intermittent occurrence of apnea-hypopnea. Clinical features include snoring or disturbed sleep, reduced concentration and memory, mood disorders, and excessive sleepiness (ES). Left undiagnosed and untreated, OSA may have detrimental consequences, including cardiovascular (CV) morbidity and mortality, decreased health-related quality of life, and increased incidence of motor vehicle accidents. As most individuals affected by OSA will initially present in the primary care setting, primary care physicians have the opportunity to recognize the condition and refer patients for treatment when necessary. Management of the condition should include lifestyle changes and continuous positive airway pressure (CPAP) treatment if required. Wakefulness-promoting agents may be considered if ES persists despite CPAP. Effective intervention for OSA not only provides symptomatic benefits, but also improves hypertension and reduces the risk for fatal and nonfatal CV events associated with the condition.

Optimal treatment of obstructive sleep apnea and excessive sleepiness

INTRODUCTION

Collapsibility of the upper airway in obstructive sleep apnea (OSA) causes repeated arousals from sleep, decreased oxygen saturation of the blood, and excessive sleepiness (ES). Patients with OSA are at increased risk of cardiovascular and cerebrovascular disease, and experience occupational and vehicular accidents more frequently than the general population. Furthermore, the life expectancy of patients with untreated OSA is significantly reduced.

METHODS

A MEDLINE search of articles published between 2003 and 2008 was conducted using the search terms: obstructive sleep apnea [ti/ab] AND treatment; obstructive sleep apnoea [ti/ab] AND treatment; and excessive sleepiness [ti/ab] AND treatment. Searches were limited to articles in English; clinical trials; meta-analyses; practice guidelines; randomized, controlled trials; and reviews.

RESULTS

Continuous positive airway pressure (CPAP) is the reference-standard treatment for patients with OSA. CPAP addresses the symptoms of OSA and reduces the risk of heart disease and depression associated with this sleep disorder. However, the efficacy of CPAP is contingent on patient adherence, and >or=4 hours of therapy per night are required for patients with OSA to experience significant clinical benefits. However, reports of nonadherence to CPAP therapy range from 29% to 83%. Other therapies are available for patients who refuse or cannot adhere to CPAP treatment, including dental devices and surgery, but these treatments are generally considered to be less efficacious. A significant number of patients continue to experience residual ES despite CPAP treatment. Pharmacologic therapies, eg, modafinil and armodafinil, may be of use in patients with OSA to improve tolerance with CPAP or to address residual ES.

CONCLUSION

There are a variety of treatments available for patients with OSA. Successful treatment involves encouraging patient compliance with CPAP or oral appliances. Primary-care physicians play a crucial role in recognizing this disorder and ensuring the best possible outcome through support and education.

Effect of weight reduction on rhinometric measurements in overweight patients with obstructive sleep apnea

BACKGROUND

Elevated nasal resistance and obesity predispose to obstructive sleep apnea (OSA). Weight loss has been shown to result in an alleviation of OSA, but its effect on nasal airflow has not been studied.

METHODS

This study was a prospective, randomized, controlled study with two parallel groups. A total of 52 adult overweight patients (body mass index [BMI], 28-40 kg/m2) with mild obstructive sleep apnea (apnea-hypopnea index (AHI), 5-15) were randomized into two study groups. The intervention group (n = 26) followed a very low calorie diet with a supervised lifestyle intervention while the control group (n = 26) received routine lifestyle counseling. The changes in BMI, total nasal resistance, total nasal volume, and quality of life scores (Mini Rhinoconjunctivitis Quality of Life Questionnaire, MiniRQLQ) were assessed at baseline and after the intervention at 3 months.

RESULTS

The reduction in BMI in the intervention group was significantly greater than that achieved by patients in the control group (5.4 kg/m2 versus 0.5 kg/m2). Accordingly, AHI was reduced by 3.2 events/hour in the intervention group and by 1.3 in the control group. However, there were no significant changes in rhinometric measurements despite significant weight loss. There was no correlation between the reduction of BMI and the change in nasal resistance or MiniRQLQ scores.

CONCLUSION

Weight reduction does not seem to have any effect on nasal resistance or volume in overweight patients with mild OSA. Patients with OSA and impaired nasal breathing need specific medical or surgical treatment to restore nasal airflow.

The epidemiology of adult obstructive sleep apnea

Obstructive sleep apnea is a chronic condition characterized by frequent episodes of upper airway collapse during sleep. Its effect on nocturnal sleep quality and ensuing daytime fatigue and sleepiness are widely acknowledged. Increasingly, obstructive sleep apnea is also being recognized as an independent risk factor for several clinical consequences, including systemic hypertension, cardiovascular disease, stroke, and abnormal glucose metabolism. Estimates of disease prevalence are in the range of 3% to 7%, with certain subgroups of the population bearing higher risk. Factors that increase vulnerability for the disorder include age, male sex, obesity, family history, menopause, craniofacial abnormalities, and certain health behaviors such as cigarette smoking and alcohol use. Despite the numerous advancements in our understanding of the pathogenesis and clinical consequences of the disorder, a majority of those affected remain undiagnosed. Simple queries of the patient or bed-partner for the symptoms and signs of the disorder, namely, loud snoring, observed apneas, and daytime sleepiness, would help identify those in need of further diagnostic evaluation. The primary objective of this article is to review some of the epidemiologic aspects of obstructive sleep apnea in adults.

Positional therapy for obstructive sleep apnea patients: A 6-month follow-up study

BACKGROUND

Approximately half of obstructive sleep apnea (OSA) patients are positional (i.e., the majority of their breathing abnormalities during sleep appear in the supine posture). Little information exists as to whether avoiding the supine posture during sleep (positional therapy) is a valuable form of therapy for these patients.

AIM

To assess the use of positional therapy (by the tennis ball technique [TBT]) during a 6 month period in 78 consecutive positional OSA patients.

METHODS

Demographic, polysomnographic, and self-reported questionnaire data on the use of the TBT were analyzed.

RESULTS

Of the 50 patients who returned the questionnaire, 19 (38%) (group A) said they were still using the TBT, and 12 (24%) (group B) said they used it initially and stopped using it within a few months but were still avoiding the supine position during sleep. Nineteen patients (38%) (group C) stopped using the TBT within a few months but did not learn how to avoid the sleep supine posture. Patients still using the TBT showed a significant improvement in their self-reported sleep quality (P < .005) and daytime alertness (P < .046) and a decrease in snoring loudness (P < .001). Patients of groups A and B were older than patients who did not comply with this therapy (P < .001). The main reason for patients stopping the use of the TBT in group C was that using it was uncomfortable.

CONCLUSIONS

Positional therapy appears to be a valuable form of therapy mainly for some older aged positional OSA patients.

The effect of sibutramine-assisted weight loss in men with obstructive sleep apnoea

OBJECTIVE

Obstructive sleep apnoea (OSA) occurs frequently in obese patients and may be reversible with weight loss. Obstructive sleep apnoea and obesity are both independent risk factors for hypertension and increased sympathetic activity. Sibutramine has been increasingly used in the management of obesity, but is relatively contraindicated in patients with hypertension. No studies have investigated the effect of sibutramine on OSA, blood pressure and heart rate. We aimed to assess the changes in OSA and cardiovascular parameters in obese men with OSA enrolled in a sibutramine-assisted weight loss programme (SIB-WL).

DESIGN

Open uncontrolled cohort study of obese male subjects with OSA in an SIB-WL.

SUBJECTS

Eighty-seven obese (body mass index =34.2+/-2.8 kg/m(2)) middle-aged (46.3+/-9.3 years) male subjects with symptomatic OSA (Epworth score 13.4+/-3.6; respiratory disturbance index (RDI) 46.0+/-23.1 events/h) completed the study.

RESULTS

At 6 months, there was significant weight loss (8.3+/-4.7 kg, P<0.0001), as well as a reduction in waist and neck circumference and sagittal height (all P<0.0001). These changes were accompanied by a reduction in OSA severity (RDI fell by 16.3+/-19.4 events/h and Epworth score by 4.5+/-4.6), both P<0.0001). There was no significant change to systolic (P=0.07) or diastolic blood pressure (P=0.87); however, there was a mild rise in resting heart rate (P<0.0001).

CONCLUSION

Moderate (approximately 10%) weight loss with SIB-WL results in improvement in OSA severity without increase in blood pressure in closely monitored OSA subjects.

Factores que influyen en el síndrome de apneas-hipopneas durante el sueño

BACKGROUND AND OBJECTIVE

Evaluate the influence of some variables (gender, age, alcohol intake and obesity) on the apnea/hypopnea index (AHI) in patients with sleep apnea/hypopnea syndrome (SAHS).

PATIENTS AND METHOD

We retrospectively reviewed medical records of patients with SAHS in the Hospital General Universitario of Murcia. We assessed demographic variables, alcohol intake, Epworth's scale, obesity and cardiorespiratory polygraphy or polysomnography. A multivariate regression model was used to explain the AHI in relation with other variables.

RESULTS

We reviewed 127 medical records of patients with SAHS. Alcohol intake was the most powerful variable influencing the AHI, followed by the numeric value of the Epworth's Scale. No statistical significance was found with regard to the the rest of variables.

CONCLUSIONS

In patients with SAHS, the AHI can be related to the alcohol intake and the numeric value of Epworth's Scale.

Treatment of sleep disorders in elderly patients

Sleep disorders are common among the elderly and are associated with diminished quality of life, increased risk for development of psychiatric disorders, inappropriate use of sleep aids, and decreased daytime functioning. The most common and important sleep disorders in the elderly include insomnia, obstructive sleep apnea syndrome, restless legs syndrome, rapid eye movement sleep behavior disorder, and the advanced sleep phase syndrome. In this article, we summarize the current treatment strategies for each of these sleep-related disorders. Before contemplating specific treatments, the authors recommend that more conservative and nonpharmacologic therapies be attempted first because the elderly are more likely to have medication side effects or complications related to surgery. Many sleep problems can be treated by simple sleep hygiene modifications that can be implemented and adopted easily. For others, therapies that specifically consider older adults may be required. For each of the sleep disorders we provide an updated discussion of therapies beginning with diet and lifestyle, pharmacologic treatment, interventional procedures, surgery, assistive devices, physical and speech therapy, exercise, and emerging therapies with specific considerations for older adults.

Epidemiology of obstructive sleep apnea: a population health perspective

Population-based epidemiologic studies have uncovered the high prevalence and wide severity spectrum of undiagnosed obstructive sleep apnea, and have consistently found that even mild obstructive sleep apnea is associated with significant morbidity. Evidence from methodologically strong cohort studies indicates that undiagnosed obstructive sleep apnea, with or without symptoms, is independently associated with increased likelihood of hypertension, cardiovascular disease, stroke, daytime sleepiness, motor vehicle accidents, and diminished quality of life. Strategies to decrease the high prevalence and associated morbidity of obstructive sleep apnea are critically needed. The reduction or elimination of risk factors through public health initiatives with clinical support holds promise. Potentially modifiable risk factors considered in this review include overweight and obesity, alcohol, smoking, nasal congestion, and estrogen depletion in menopause. Data suggest that obstructive sleep apnea is associated with all these factors, but at present the only intervention strategy supported with adequate evidence is weight loss. A focus on weight control is especially important given the expanding epidemic of overweight and obesity in the United States. Primary care providers will be central to clinical approaches for addressing the burden and the development of cost-effective case-finding strategies and feasible treatment for mild obstructive sleep apnea warrants high priority.

Outcome success in obesity

Intentional weight loss improves many of the medical complications associated with obesity. Moreover, many of these beneficial effects have a dose-dependent relationship with the amount of weight lost and begin after only modest weight losses of 5% to 10% of initial body weight. There is no conclusive evidence that weight loss decreases mortality in obese people. The therapeutic effect of weight loss on risk factors for cardiovascular disease (insulin resistance and diabetes, dyslipidemia, and hypertension) has received the most attention in clinical trials. The hazard of developing coronary heart disease is directly related to the concomitant burden of risk factors. Modest weight loss can affect the entire cluster of risk factors simultaneously. Both negative energy balance and weight loss improve insulin sensitivity and glycemic control in obese patients with type 2 diabetes. Most studies have found that weight loss decreases serum triglyceride, total cholesterol, and low-density lipoprotein cholesterol concentrations and increases serum high-density lipoprotein cholesterol concentration. Regain of weight leads to relapse in triglyceride and cholesterol concentrations. Weight loss, independent of sodium restriction, decreases systolic and diastolic blood pressure. Dietary intervention is the cornerstone of weight-loss therapy. Most diets proposed for losing weight vary in two principal dimensions: energy content and macronutrient composition. Manipulation of food macronutrient content, energy density, and portion size can help decrease energy intake and facilitate weight loss.