Sleep and Breathing

To evaluate the intensity of nocturnal hypoxemia associated with sleepiness in Peruvian men with a diagnosis of obstructive sleep apnea (OSA). We carried out a secondary data analysis based on a study which includes patients with OSA who were seen in a private hospital in Lima, Peru from 2006 to 2012. We included male adults who had polysomnographic recordings and who answered the Epworth sleepiness scale (ESE). The intensity of nocturnal hypoxemia (oxygen saturation ≤90 %) was classified in four new categories: 0, <1, 1 to 10 and >10 % total sleep time with nocturnal hypoxemia (NH). When the ESE score was higher than 10, we used the definitions presence or absence of sleepiness. We used Poisson regression models with robust variance to estimate crude and adjusted prevalence ratios (PR) for association between sleepiness and NH. 518 male patients with OSA were evaluated. Four hundred and fifty-two (87 %) patients had NH and 262 (51 %) had sleepiness. Of the 142 (27.4 %) patients who had >10 % total sleep time with NH, 98 (69.0 %) showed sleepiness and had a greater probability of sleepiness prevalence, with a crude PR of 1.82 (95 % CI 1.31–2.53). This association persisted in the multivariate models. We found an association between NH and sleepiness. Only patients with the major intensity of NH (over 10 % of the total sleep time) had a greater probability of sleepiness. This suggests that sleepiness probably occurs after a chronic process and after overwhelming compensatory mechanisms.

Epidemiologic and genetic studies of obstructive sleep apnoea (OSA) are limited by a lack of large-scale, well-characterized OSA cohorts. These studies require large sample size to provide adequate power to detect differences between groups. This study describes the development of such a cohort (The Western Australian Sleep Health Study) in OSA patients of Caucasian–European origin attending the only public sleep clinic in Western Australia (WA). The main aim of the study is to phenotype 4,000 OSA patients in order to define the genetics of OSA and its co-morbidities. Almost all underwent laboratory-based attended polysomnography (PSG). Currently complete data (questionnaire, biochemistry, DNA, and PSG) has been obtained on over 3,000 individuals and will reach the target of 4,000 individuals by the end of 2010. In a separate but related study, we have developed a sleep study database containing data from all patients who have undergone PSG at the sleep laboratory since its inception in 1988 until the present day (over 30,000 PSG studies representing data from approximately 20,000 individuals). In addition, data from both cohorts have been linked prospectively to statutory health data collected by the WA Department of Health. This study will be the largest sleep clinic cohort database internationally with access to genetic and epidemiological data. It is unique among sleep clinic cohorts because of its size, the breadth of data collected and the ability to link prospectively to statutory health data. It will be a major tool to comprehensively assess genetic and epidemiologic factors determining OSA and its co-morbidities.

Obstructive sleep apnea (OSA) is associated with various cardiovascular disorders. This study aimed to investigate the effects of OSA on left ventricular (LV) function in patients with OSA who were at risk for heart failure but who had not yet developed structural heart changes. The study also sought to determine the effects of continuous positive airway pressure (CPAP) in these patients. In a retrospective study, consecutive patients with polysomnographic OSA (apnea-hypopnea index [AHI] >5) were categorized into mild (AHI < 15), moderate (15 ≤ AHI < 30), and severe OSA (AHI ≥ 30) groups. The subjects were patients with OSA and at risk for heart failure who had not yet developed structural heart changes. All study participants underwent echocardiography and two-dimensional speckle tracking analysis, and their global longitudinal strain (GLS) was calculated. Of 275 patients, there were 31 with mild, 92 with moderate, and 152 with severe OSA. Of patients with moderate to severe OSA (AHI ≥ 20), 206 started CPAP and 92 patients underwent follow-up echocardiogram and speckle tracking echo analysis (median period of CPAP use: 283 days [258 to 391]). GLS was significantly reduced in patients with moderate and severe OSA compared with mild OSA (−17.8±3.1 vs. −18.0±2.6 vs. −19.3±2.8%, p=0.038). The proportion of patients with GLS ≥ −18% was significantly higher among the patients with moderate to severe OSA than among those with mild OSA. GLS improved after CPAP therapy in patients with moderate to severe OSA (GLS: −18.1±2.7% to −19.0±2.8%, p=0.004). Significant improvement in GLS was confirmed, particularly among patients with good CPAP adherence. Moderate to severe OSA is associated with LV dysfunction and can be significantly improved by CPAP therapy.

Heart failure (HF) is a major public health problem associated with high rates of morbidity and mortality. Patients with HF exhibit a high prevalence of sleep-disordered breathing (SDB). We have investigated the long-term impact of positive airway pressure (PAP) therapy on heart function and clinical outcomes in patients with advanced HF and concomitant SDB. We assessed 18 patients with advanced HF (New York Heart Association (NYHA) functional classification III–IV) and concomitant SDB (diagnosed with polysomnography) either of obstructive or central type. Eleven patients who received PAP therapy (auto-titrating PAP or adaptive servo-ventilation) for 12 months were compared with seven patients who refused this therapy. All participants were assessed at both baseline and end of follow-up for NYHA functional status, left and right ventricular function, neurohormonal activation, and exercise tolerance. The rates of hospitalization, deaths, and the combination of both were also recorded. Patients treated with PAP achieved better functional status, higher left ventricular ejection fraction, improved longitudinal right ventricular contractile function, lower levels of b-type natriuretic peptide, and greater exercise performance compared to those who remained untreated. PAP-treated group had a significantly lower incidence of the prespecified combined end-point (i.e., hospital admissions and death) than the control group (87.5 vs. 18.2%, p = 0.013). Interestingly, the mortality rate was 28% (two out of seven patients) in the control group, while no deaths were recorded in the PAP-treated group. In this preliminary study, we found that treatment of SDB, irrespective of type, in stable patients with advanced HF receiving optimal medical therapy was associated with improvement in cardiac functional status, ventricular contraction, physical performance, and neurohormonal status, leading to better clinical outcomes.

It has been shown that shift work constitutes a great health hazard, particularly when chronodisruption is involved. Anesthetists are used to working for a certain number of 24-h shifts every month. The work-related lack of sleep in combination with light exposure is suspected to alter melatonin courses. The main aim of the present study was to analyze circadian melatonin profiles before, during, and after a 24-h shift in anesthetists and medical students (controls). Furthermore, we evaluated possible differences in melatonin profiles between the groups. Interactions between specific parameters were calculated. Over three consecutive days, including a 24-h shift, urine samples were collected daily at five time points. 6-Sulfateoxymelatonin (aMT6-s) courses were assayed using a commercially available competitive immunoassay kit. Ten anesthetists aged between 29 and 35 years and ten medical students aged between 25 and 31 years were included in the study. aMT6-s fluctuated between nocturnal values of (mean [range]) 2.2 (1.4; 3.0) pg/ml and morning values of 25.5 (12.1; 39.0) pg/ml. A marked circadian rhythm of aMT6-s courses was observed in both groups. Analyses of variance showed an effect of the factor “time” on aMT6-s concentrations but not of the factor “anesthetists versus students”. Correlations between aMT6-s, the amount of sleep, and the time since the last extended duration shift could be found. The results show no evidence for a single 24-h shift having a great impact on circadian disruption as evidenced by a similar melatonin profile for both groups over the study phase.

Obesity, obstructive sleep apnea (OSA), and type 2 diabetes mellitus (T2DM) are associated with chronic low-grade inflammation and oxidative stress. In adults, increased lipid peroxidation, a marker of oxidative stress, was found in both metabolic syndrome and OSA. Studies on oxidative stress in children with T2DM and OSA are scarce. Plasma oxidized low-density lipoprotein (Ox-LDL) levels were evaluated in obese children and adolescents with/without T2DM, and the contribution of OSA to oxidative stress was investigated. Ten patients with T2DM, 8 with impaired glucose tolerance (IGT), and 20 body mass index-standard deviation score (BMI-SDS)-matched non-diabetic children (controls) were studied. They all underwent overnight polysomnography. Fasting plasma concentrations of Ox-LDL were measured and compared to the glycemic status and to the presence of OSA. Fourteen patients (36%) were diagnosed with OSA and 21 (55%) with hypertension. There were no significant group differences in plasma Ox-LDL levels or between patients with/without OSA. Plasma Ox-LDL levels were significantly higher among patients with hypertension compared to controls (P = 0.01), while they correlated with homeostasis model assessment (P = 0.02), BMI-SDS (P = 0.049), and systolic blood pressure (P = 0.002). The findings of this pilot study suggest that increased lipid peroxidation is associated with insulin resistance and hypertension in obese children and adolescents, while OSA has most likely minor influence.

Mucopolysaccharidosis (MPS) encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans in organs and tissues. Respiratory disorders occur in all MPS types. In these patients, the prevalence of obstructive sleep apnea syndrome (OSAS), which may confer additional morbidity, remains overlooked, and the results of the few existing studies are controversial. The present study aimed to characterize the prevalence of OSAS in patients with MPS types I, II, and VI in a reference center. Forty-five patients with MPS (I, n = 17; II, n = 16; and VI; n = 12) in the Centro de Referência em Erros Inatos do Metabolismo, who underwent full-night polysomnography, were enrolled in a retrospective study. Demographic data and clinical history were collected from medical records of the first medical consultation. The prevalence of OSAS in patients with MPS was 69.8 %. MPS type I patients seemed to be more susceptible to OSA-induced hypoxemia, as indicated by reduced mean SpO2 levels during both NREM and rapid eye movement sleep as well as during SpO2 nadir. Patients with MPS displayed a high prevalence of OSAS, often with moderate to high severity. Together, our results reinforce the need for OSAS screening in all patients with MPS.

We designed this study to assess the signal failure and sensor loss of unattended type 2 comprehensive polysomnography (PSG) and compared that with in-lab attended PSG. Type 2 PSG was performed for 41 patients. The signal failure was estimated and compared to the signal failure in 60 patients for the in-lab PSGs. The signal failure in each individual electroencephalographic (EEG) channel, complete EEG signals, electro-oculography (EOG), naso–oral flow, and thoracic belt were significantly greater in the unattended sleep studies. The failure rate for the different signals ranged from 0.128 min in electrocardiography (EKG) to 67.36 min in the thoracic belt signal. However, that did not affect the success rate of the studies. Acceptable scorable data was available in 97% of the performed unattended PSGs. Unattended type 2 sleep studies can be performed for clinical use in the evaluation of sleep disordered breathing with low signal failure and sensor loss if the proper hook-up procedure was followed.

Mục tiêu của nghiên cứu này là mô tả quá trình phát triển và đánh giá tính khả dụng của một mẫu trợ giúp quyết định cho bệnh nhân (PtDA) dành cho những bệnh nhân mới được chẩn đoán mắc chứng ngưng thở khi ngủ tắc nghẽn (OSA) và chưa điều trị. Một PtDA dựa trên web đã được phát triển, tập trung vào hai phương pháp điều trị đầu tiên là áp suất đường thở dương liên tục (CPAP) và máng chỉnh hàm (MAS). Quá trình phát triển được hướng dẫn bởi các tiêu chuẩn Trợ giúp Quyết định Bệnh nhân Quốc tế (IPDAS). Tính khả dụng của mẫu trợ giúp đã được đánh giá cho những cá nhân có nguy cơ cao mắc OSA dựa trên bảng hỏi STOP-Bang, chấp nhận của bệnh nhân đối với trợ giúp quyết định, Thang đo Tính khả dụng Hệ thống (SUS) và phân tích nội dung từ phản hồi của người dùng. Có 80 người tham gia đủ điều kiện đã hoàn thành khảo sát. Độ tuổi trung bình là 54 tuổi (SD = 8.9), 60 % trong mẫu là nam, 78 % có trình độ học vấn đại học và 64 % đang làm việc toàn thời gian. Thời gian trung bình để hoàn thành PtDA của người tham gia là 13.7 phút (SD = 9.6), trong đó 39 người chọn CPAP, 25 người chọn MAS và 16 người không chọn phương pháp nào. Điểm SUS trung bình là 78.22 (SD = 15.13). Phần lớn cá nhân cho rằng PtDA hữu ích trong việc đưa ra quyết định (n = 77, 96 %) và sẽ giới thiệu cho người khác (n = 77, 96 %), trong khi một phần ba (n = 26, 33 %) cho rằng PtDA nghiêng về CPAP. Thang SUS chỉ ra rằng PtDA là chấp nhận được và hữu ích đối với người tham gia. Phản hồi từ người dùng đã được sử dụng để cải tiến mẫu trợ giúp, và nó sẽ tiếp tục được thử nghiệm thêm trên các bệnh nhân tại Phòng khám Rối loạn Giấc ngủ Vancouver.