Obstructive sleep apnea (OSA) is a common clinical condition, with a variable and underestimated prevalence. OSA is the main condition associated with secondary systemic arterial hypertension, as well as with atrial fibrillation, stroke, and coronary artery disease, greatly increasing cardiovascular morbidity and mortality. Treatment with continuous positive airway pressure is not tolerated by all OSA patients and is often not suitable in cases of mild OSA. Hence, alternative methods to treat OSA and its cardiovascular consequences are needed. In OSA patients, regular physical exercise has beneficial effects other than weight loss, although the mechanisms of those effects remain unclear. In this population, physiological adaptations due to physical exercise include increases in upper airway dilator muscle tone and in slow-wave sleep time; and decreases in fluid accumulation in the neck, systemic inflammatory response, and body weight. The major benefits of exercise programs for OSA patients include reducing the severity of the condition and daytime sleepiness, as well as increasing sleep efficiency and maximum oxygen consumption. There are few studies that evaluated the role of physical exercise alone for OSA treatment, and their protocols are quite diverse. However, aerobic exercise, alone or combined with resistance training, is a common point among the studies. In this review, the major studies and mechanisms involved in OSA treatment by means of physical exercise are presented. In addition to systemic clinical benefits provided by physical exercise, OSA patients involved in a regular, predominantly aerobic, exercise program have shown a reduction in disease severity and in daytime sleepiness, as well as an increase in sleep efficiency and in peak oxygen consumption, regardless of weight loss.

Keywords: Exercise therapy; Sleep apnea, obstructive; Cardiovascular diseases.

Objective: To investigate the extent to which exercise is associated with symptoms in patients with severe obstructive sleep apnea (OSA). Methods: We included subjects with an apnea-hypopnea index (AHI) > 30 events/h who completed validated sleep and exercise questionnaires. We compared symptom frequency/scores between exercisers and nonexercisers, adjusting for the usual confounders. Results: The sample included 907 nonexercisers and 488 exercisers (mean age, 49 ± 14 years; mean AHI, 53 ± 20 events/h; 81% men). Nonexercisers and exercisers differed significantly in terms of obesity (72% vs. 54%), the mean proportion of sleep in non-rapid eye movement stage 3 sleep (9 ± 8% vs. 11 ± 6%), and tiredness (78% vs. 68%). Nonexercisers had a higher symptom frequency/scores and poorer sleep quality. Adjustment for exercise weakened the associations between individual symptoms and the AHI, indicating that exercise has a mitigating effect. In binary logistic models, exercise was associated with approximately 30% lower adjusted questionnaire1 score > 2, tiredness; poor-quality sleep, unrefreshing sleep, and negative mood on awakening. Although the odds of an Epworth Sleepiness Scale score > 10 were lower in exercisers, that association did not withstand adjustment for confounders. Conclusions: Exercise is associated with lower frequency/intensity of symptoms in patients with severe OSA. Because up to one third of patients with severe OSA might exercise regularly and therefore be mildly symptomatic, it is important not to rule out a diagnosis of OSA in such patients.

Keywords: Sleep apnea syndromes; Exercise; Sleepiness; Polysomnography.

Objective: To evaluate lung function and inspiratory muscle strength, correlating them with exercise tolerance, in obese individuals with obstructive sleep apnea syndrome (OSAS). Methods: The sample comprised 31 adult subjects with moderate-to-severe OSAS diagnosed by polysomnography. We used spirometry to measure FVC, FEV1, and FVC/FEV1 ratio, using pressure manometry to measure MIP and MEP. The incremental shuttle walk test (ISWT) and the six-minute walk test (6MWT) were used in order to determine functional exercise capacity. Results: In this sample, the mean values for FVC (% of predicted), FEV1 (% of predicted): MIP, and MEP were 76.4 ± 12.3%, 80.1 ± 6.3%, 60.0 ± 21.9 cmH2O, and 81.3 ± 22.2 cmH2O, respectively. The mean distances covered on the ISWT and 6MWT were 221 ± 97 m and 480.8 ± 67.3 m, respectively. The ISWT distance showed moderate positive correlations with FVC (r = 0.658; p = 0.001) and FEV1 (r = 0.522; p = 0.003). Conclusions: In this sample of obese subjects with untreated OSAS, lung function, inspiratory muscle strength, and exercise tolerance were all below normal. In addition, we found that a decline in lung function, but not in respiratory muscle strength, was associated with exercise tolerance in these patients.

Keywords: Sleep apnea syndromes; Exercise tolerance; Respiratory function tests; Respiratory muscles.

Recent years have seen a growing interest in the use of portable monitoring devices for the diagnosis of obstructive sleep apnea syndrome. These have the potential to be used in lieu of the more complicated and uncomfortable alternative, polysomnography, which has long been considered to be the gold standard for the diagnosis of this relatively prevalent condition. Following their approval in 2008 by the Center of Medicare and Medicaid Services, the federal agency which administers Medicare and Medicaid in the United States, there has been extensive discussion about the utility and validity of these devices for use in the diagnosis of obstructive sleep apnea syndrome. Although there are various models of portable monitoring devices, the literature contains little information regarding how each device should be used in specific age groups, patients presenting comorbidities, and asymptomatic patients. Additionally, studies about the cost-effectiveness of this diagnostic method are scarce and conflicting. Therefore, this objective of this study was to review what has been learned about portable monitoring devices over time, as well as to examine the recent progress, advantages, limitations, and applications of these devices in the diagnosis of obstructive sleep apnea syndrome in different groups of patients.

Keywords: Sleep apnea, obstructive/diagnosis; Polysomnography; Diagnostic equipment; Monitoring, ambulatory.

1. LabSono, Hospital Mãe de Deus Center, Porto Alegre (RS) Brasil. 2. Laboratório do Sono, Laboratório de Investigação Médica 63, Divisão de Pneumologia, Instituto do Coração – InCor – Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo – HCFMUSP – São Paulo (SP) Brasil.

Objective: To determine the prevalence of obstructive sleep apnea syndrome (OSAS), as well as to identify factors associated with a greater risk of developing OSAS, among truck drivers. Methods: The study population comprised 209 truck drivers (mean age, 38.8 years; 98.5% males) at two branches of a transportation company. The mean body mass index was 26.5 ± 4.4 kg/m2. The participants completed questionnaires regarding sociodemographic data, physical activity and OSAS. The prevalence of OSAS was estimated using the Berlin Questionnaire, associations between OSAS and the factors studied being assessed through univariate and multivariate regression analysis. Results: The prevalence of OSAS in the population was 11.5%. Of the 209 truck drivers, 72 (34.5%) reported having fallen asleep while driving and 81 (38.7%) reported snoring. The following variables were found to present statistically significant associations with OSAS: informal employment (OR = 0.27; p = 0.01); body mass index ≥ 25 kg/m2 (OR = 13.64; p = 0.01); and poor sleep quality (OR = 3.00; p = 0.02). Conclusions: The prevalence of OSAS in this study was lower than that reported in other studies of truck drivers and yet higher that that observed for the general population. In addition, our results suggest that work characteristics, such as employment status, are associated with OSAS. These data show the relevance of considering work activity in studies of factors associated with OSAS.

Keywords: Sleep apnea, obstructive; Sleep disorders; Questionnaires.

Objective: To validate the Portuguese-language version of the STOP-Bang (acronym for Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index, Age, Neck circumference, and Gender) questionnaire, culturally adapted for use in Brazil, as a means of screening for obstructive sleep apnea (OSA) in adults. Methods: In this validation study, we enrolled patients ≥ 18 years of age, recruited between May of 2015 and August of 2016. All patients completed the STOP-Bang questionnaire and underwent overnight polysomnography. To evaluate the performance of the questionnaire, we used contingency tables and areas under the (receiver operating characteristic) curve (AUCs). Results: We included 456 patients. The mean age was 43.7 ± 12.5 years, and 291 (63.8%) of the patients were male. On the basis of the apnea-hypopnea index (AHI), we categorized OSA as mild/moderate/severe (any OSA; AHI ≥ 5 events/h), moderate/severe (AHI ≥ 15 events/h), or severe (AHI ≥ 30 events/h). The overall prevalence of OSA was 78.3%, compared with 52.0%, and 28.5% for moderate/severe and severe OSA, respectively. The most common score on the STOP-Bang questionnaire was 4 points (n = 106), followed by 3 points (n = 85) and 5 points (n = 82). An increase in the score was paralleled by a reduction in sensitivity with a corresponding increase in specificity for all AHI cut-off points. The AUCs obtained for the identification of any, moderate/severe, and severe OSA were: 0.743, 0.731, and 0.779, respectively. For any OSA, the score on the questionnaire (cut-off, ≥ 3 points) presented sensitivity, specificity, and accuracy of 83.5%, 45.5%, and 75.2%, respectively. Conclusions: The STOP-Bang questionnaire performed adequately for OSA screening, indicating that it could be used as an effective screening tool for the disorder.

Keywords: Sleep apnea, obstructive/diagnosis; Polysomnography; Diagnostic techniques and procedures; Surveys and questionnaires.

Objective: Obstructive sleep apnea syndrome (OSAS) has a high prevalence and carries significant cardiovascular risks. It is important to study new therapeutic approaches to this disease. Positional therapy might be beneficial in reducing the apnea-hypopnea index (AHI). Imaging methods have been employed in order to facilitate the evaluation of the airways of OSAS patients and can be used in order to determine the effectiveness of certain treatments. This study was aimed at determining the influence that upper airway volume, as measured by cervical CT, has in patients diagnosed with OSAS. Methods: This was a quantitative, observational, cross-sectional study. We evaluated 10 patients who had been diagnosed with OSAS by polysomnography and on the basis of the clinical evaluation. All of the patients underwent conventional cervical CT in the supine position. Scans were obtained with the head of the patient in two positions (neutral and at a 44° upward inclination), and the upper airway volume was compared between the two. Results: The mean age, BMI, and neck circumference were 48.9 ± 14.4 years, 30.5 ± 3.5 kg/m2, and 40.3 ± 3.4 cm, respectively. The mean AHI was 13.7 ± 10.6 events/h (range, 6.0-41.6 events/h). The OSAS was classified as mild, moderate, and severe in 70%, 20%, and 10% of the patients, respectively. The mean upper airway volume was 7.9 cm3 greater when the head was at a 44° upward inclination than when it was in the neutral position, and that difference (17.5 ± 11.0%) was statistically significant (p = 0.002). Conclusions: Elevating the head appears to result in a significant increase in the caliber of the upper airways in OSAS patients.

Keywords: Sleep apnea, obstructive/prevention and control; Sleep apnea, obstructive/therapy; Tomography.

Objective: To evaluate the performance of the No-Apnea score, a simplified screening instrument for obstructive sleep apnea (OSA), by gender. Methods: This was a cross-sectional study including adults undergoing full polysomnography. The No-Apnea model comprises two items (neck circumference and age) with a total score of 0 to 9. The severity of OSA was categorized, on the basis of the apnea-hypopnea index, as any (≥ 5 events/h), moderate-to-severe (≥ 15 events/h), or severe (≥ 30 events/h). The performance of the No-Apnea instrument was assessed by determining the area under the (ROC) curve (AUC) and by constructing contingency tables. Results: We evaluated a total of 6,606 adults (53.8% men). For categorizing the level of OSA severity, the No-Apnea score had a sensitivity of 83.9-93.0% and a specificity of 57.3-35.2%. At all OSA severity levels, the No-Apnea score exhibited higher sensitivity and lower specificity in men than in women. The No-Apnea score proved to be an appropriate screening model for patients in general or when separated by gender or severity of OSA (AUC > 0.7 for all). The discriminatory power of the No-Apnea score to predict any, moderate-to-severe, and severe OSA was similar between genders (p = 0.109, p = 0.698, and p = 0.094, respectively). Conclusions: In a sample of adults referred to the sleep laboratory, there was no significant difference between men and women in terms of the discriminatory power of the No-Apnea instrument in for screening for OSA severity.

Keywords: Sleep apnea, obstructive/diagnosis; Polysomnography; Sex; Surveys and questionnaires.

Objective: To translate the Quebec Sleep Questionnaire (QSQ), a specific instrument for the assessment of quality of life in patients with sleep obstructive apnea, into Portuguese and to create a version that is cross-culturally adapted for use in Brazil. Methods: The Portuguese-language version was developed according to a rigorous methodology, which included the following steps: preparation; translation from English into Portuguese in three versions; reconciliation to a single version; back-translation of that version into English; comparison and harmonization of the back-translation with the original version; review of the Portuguese-language version; cognitive debriefing; text review; and arrival at the final version. Results: The Portuguese-language version of the QSQ for use in Brazil had a clarity score, as measured by cognitive debriefing, ranging from 0.81 to 0.99, demonstrating the consistency of translation and cross-cultural adaptation processes. Conclusions: The process of translating the QSQ into Portuguese and creating a version that is cross-culturally adapted for use in Brazil produced a valid instrument to assess the quality of life in patients with obstructive sleep apnea.

Keywords: Obstructive sleep apnea, Quality of life; Translations; Validation studies.

Objective: The Mallampati classification system has been used to predict obstructive sleep apnea (OSA). Upper airway soft tissue structures are prone to fat deposition, and the tongue is the largest of these structures. Given that a higher Mallampati score is associated with a crowded oropharynx, we hypothesized that the Mallampati score is associated with tongue volume and an imbalance between tongue and mandible volumes. Methods: Adult males underwent clinical evaluation, polysomnography, and upper airway CT scans. Tongue and mandible volumes were calculated and compared by Mallampati class. Results: Eighty patients were included (mean age, 46.8 years). On average, the study participants were overweight (BMI, 29.3 ± 4.0 kg/m2) and had moderate OSA (an apnea-hypopnea index of 26.2 ± 26.7 events/h). Mallampati class IV patients were older than Mallampati class II patients (53 ± 9 years vs. 40 ± 12 years; p < 0.01), had a larger neck circumference (43 ± 3 cm vs. 40 ± 3 cm; p < 0.05), had more severe OSA (51 ± 27 events/h vs. 24 ± 23 events/h; p < 0.01), and had a larger tongue volume (152 ± 19 cm3 vs. 135 ± 18 cm3; p < 0.01). Mallampati class IV patients also had a larger tongue volume than did Mallampati class III patients (152 ± 19 cm3 vs. 135 ± 13 cm3; p < 0.05), as well as having a higher tongue to mandible volume ratio (2.5 ± 0.5 cm3 vs. 2.1 ± 0.4 cm3; p < 0.05). The Mallampati score was associated with the apnea-hypopnea index (r = 0.431, p < 0.001), BMI (r = 0.405, p < 0.001), neck and waist circumference (r = 0.393, p < 0.001), tongue volume (r = 0.283, p < 0.001), and tongue/mandible volume (r = 0.280, p = 0.012). Conclusions: The Mallampati score appears to be influenced by obesity, tongue enlargement, and upper airway crowding.

Keywords: Sleep apnea, obstructive; Tongue; Obesity; Diagnostic imaging.

Objective: To investigate whether the presence of obstructive sleep apnea syndrome (OSAS) alters the perception of respiratory symptoms and quality of life in COPD patients, by using specific questionnaires, as well as to determine whether scales for assessing daytime sleepiness and for screening for OSAS can be used in the triad of OSAS, COPD, and obesity. Methods: We included 66 patients diagnosed with mild-to-moderate or severe COPD and presenting with a body mass index > 27 kg/m2. After polysomnography, patients completed the Epworth sleepiness scale (ESS), the Berlin questionnaire (BQ), the modified Medical Research Council (mMRC) scale, the Baseline Dyspnea Index (BDI), and the Saint George's Respiratory Questionnaire (SGRQ). Results: Patients were first divided into two groups: COPD + OSAS (n = 46); and COPD-only (n = 20). The COPD + OSAS group was subdivided into a COPD + mild-to-moderate OSAS group (n = 32) and a COPD + severe OSAS group (n = 14), all of which were compared with the COPD-only group. There was a significant difference in mean FEV1 (L) between the COPD + OSAS groups and the COPD-only group (p = 0.073). The presence of the triad did not lead to significantly higher ESS scores, and scores > 10 had a specificity of 0.58. The BQ did not identify high risk for OSAS in the presence of the triad (specificity of 0.31). There were no significant differences in domain or total scores of the SGRQ between the COPD + OSAS groups and the COPD-only group. Conclusions: The confounding factors present in the triad of OSAS, COPD, and obesity prevented the perception of increased daytime sleepiness and high risk for OSAS. We observed no worsening of dyspnea perception or quality of life.

Keywords: Sleep apnea, obstructive; Pulmonary disease, chronic obstructive; Obesity; Surveys and questionnaires.

Objective: To estimate the prevalence of obstructive sleep apnea syndrome (OSAS) in children and adolescents with sickle cell anemia (SCA); to investigate the possible correlation between mean annual hemoglobin level and total sleep time with SpO2 < 90%, as well as between mean annual hemoglobin level and total sleep time with SpO2 < 80%; and to investigate the possible correlation between apnea-hypopnea index (AHI) and painful crisis. Methods: The study involved 85 patients with SCA. The patients completed a questionnaire, were submitted to polysomnography and underwent clinical evaluation (by a pediatrician and an otolaryngologist). An AHI > 1 was considered indicative of a diagnosis of OSAS. Results: The prevalence of OSAS was 10.6%. We found a negative correlation between mean annual hemoglobin level and total sleep time with SpO2 < 90% (r = −0.343; p = 0.002), as well as between mean annual hemoglobin level and total sleep time with SpO2 < 80% (r = −0.270; p = 0.016). There was no association between AHI and painful crisis. Conclusions: The prevalence of OSAS in this population was high (10.6%). Therefore, it is important to identify signs of OSAS as soon as possible and to determine the mean annual hemoglobin level because of the inverse correlation between that level and the total sleep time with SpO2 < 90% or < 80%.

Keywords: Prevalence; Sleep apnea, obstructive; Anemia, sickle cell; Polysomnography; Sleep apnea syndromes.

Objective: To study the impact that heated humidification instituted in the beginning of automatic positive airway pressure (APAP) therapy has on compliance with and the side effects of the treatment. Methods: Thirty-nine treatment-naïve patients with obstructive sleep apnea were randomized into two groups to receive APAP using one of two modalities: with heated humidification (APAPwith group); and without heated humidification (APAPw/o group).Patients were evaluated at 7 and 30 days after APAP initiation. The following parameters were analyzed: compliance with treatment (mean number of hours/night); side effects (dry nose or mouth, nasal obstruction and rhinorrhea); daytime sleepiness (Epworth sleepiness scale score) and subjective comfort (visual analog scale score). Patients were also evaluated in terms of residual apnea-hypopnea index (AHI), as well as mean pressures and leaks registered in the ventilators. Results: There were no differences between the two groups in terms of mean age (APAPwith: 57.4 ± 9.2; APAPw/o: 56.5 ± 10.7 years), AHI (APAPwith: 28.1 ± 14.0; APAPw/o: 28.8 ± 20.5 events/hour of sleep), baseline Epworth score (APAPwith: 11.2 ± 5.8; APAPw/o: 11.9 ± 6.3) and initial nasal symptoms. Compliance was similar in both groups (APAPwith: 5.3 ± 2.4; APAPw/o: 5.2 ± 2.3 h/night). There were no differences in any of the other parameters analyzed. Conclusions: The introduction of heated humidification at the beginning of APAP therapy provided no advantage in terms of treatment compliance or side effects of treatment.

Keywords: Humidity; Positive-pressure respiration/adverse effects; Patient compliance.