The incremental role of obstructive sleep apnoea on markers of atherosclerosis in patients with metabolic syndrome

Objective: Metabolic syndrome (MS) is associated with subclinical atherosclerosis, but the relative role of obstructive sleep apnoea (OSA) is largely unknown. The main objective of this study is to determine the impact of OSA on markers of atherosclerosis in patients with MS. Methods: Eighty-one consecutive patients with MS according to the Adult Treatment Panel III underwent a clinical evaluation, polysomnography, laboratory and vascular measurements of carotid intima media thickness (IMT), carotid-femoral pulse wave velocity (PWV) and carotid diameter (CD) in a blind fashion. OSA was defined as an apnoea-hypopnoea index (AHI) >= 15 events/hour. Multiple linear regression was performed to determine the variables that were independently associated with the vascular parameters. Results: Fifty-one patients (63%) had OSA. No significant differences existed in age, sex, MS criteria, and cholesterol levels between patients with (MS+OSA) and without OSA (MS-OSA). Compared with MS-OSA patients, MS+OSA patients had higher levels of IMT (661 +/- 117 vs. 767 +/- 140 mu m), PWV (9.6 +/- 1.0 vs. 10.6 +/- 1.6 m/s), and CD (6705 +/- 744 vs. 7811 +/- 862 mu m) (P < 0.001 for each comparison). Among patients with MS+OSA, all vascular parameters were similar in patients with and without daytime sleepiness. The independent parameters associated with IMT, PWV, and CD were AHI, abdominal circumference, and systolic blood pressure (R(2) = 0.42); AHI and systolic blood pressure (R(2) = 0.38); and AHI, age, abdominal circumference and systolic blood pressure (R(2) = 0.45), respectively. The R(2) of AHI for IMT, PWV and CD was 0.12, 0.10 and 0.20, respectively. Conclusions: OSA is very common and has an incremental role in atherosclerotic burden in consecutive patients with MS. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

CPAP and survival in moderate-to-severe obstructive sleep apnoea syndrome and hypoxaemic COPD

Obstructive sleep apnoea syndrome (OSAS) often coexists in patients with chronic obstructive pulmonary disease (COPD). The present prospective cohort study tested the effect of OSAS treatment with continuous positive airway pressure (CPAP) on the survival of hypoxaemic COPD patients. It was hypothesised that CPAP treatment would be associated with higher survival in patients with moderate-to-severe OSAS and hypoxaemic COPD receiving long-term oxygen therapy (LTOT). Prospective study participants attended two outpatient advanced lung disease LTOT clinics in Sao Paulo, Brazil, between January 1996 and July 2006. Of 603 hypoxaemic COPD patients receiving LTOT, 95 were diagnosed with moderate-to-severe OSAS. Of this OSAS group, 61 (64%) patients accepted and were adherent to CPAP treatment, and 34 did not accept or were not adherent and were considered not treated. The 5-yr survival estimate was 71% (95% confidence interval 53-83%) and 26% (12-43%) in the CPAP-treated and nontreated groups, respectively (p<0.01). After adjusting for several confounders, patients treated with CPAP showed a significantly lower risk of death (hazard ratio of death versus nontreated 0.19 (0.08-0.48)). The present study found that CPAP treatment was associated with higher survival in patients with moderate-to-severe OSAS and hypoxaemic COPD receiving LTOT.

Study into the use of continuous positive airway pressure in obstructive sleep apnoea-hypopnoea syndrome patients with daytime drowsiness

Background: Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is a respiratory disorder with high morbidity and mortality. Continuous positive airway pressure (CPAP) is the most commonly prescribed conservative treatment for adults with OSAHS. CPAP therapy normalises or decreases OSAHS symptoms and can reduce and prevent OSAHS complications. Aims: To evaluate adherence to nasal CPAP treatment and CPAP impact on daytime drowsiness. Method: A sample of 20 patients evaluated for daytime drowsiness using the Epworth sleepiness scale and interviewed for adherence to nasal CPAP use. Results: There was a significant decrease in the level of daytime sleepiness of the patients users of nasal CPAP (p=0.017); patients not using nasal CPAP experienced a decrease without statistical significance (p=0.162). 100% of CPAP users reported benefits and 50% of these reported related discomforts. Conclusions: Patients with OSAHS that use CPAP have a greater reduced level of sleepiness than those who do not use it.

Trazodone increases arousal threshold in obstructive sleep apnoea.

A low arousal threshold is believed to predispose to breathing instability during sleep. The present authors hypothesised that trazodone, a nonmyorelaxant sleep-promoting agent, would increase the effort-related arousal threshold in obstructive sleep apnoea (OSA) patients. In total, nine OSA patients, mean+/-sd age 49+/-9 yrs, apnoea/hypopnoea index 52+/-32 events.h(-1), were studied on 2 nights, one with trazodone at 100 mg and one with a placebo, in a double blind randomised fashion. While receiving continuous positive airway pressure (CPAP), repeated arousals were induced: 1) by increasing inspired CO(2) and 2) by stepwise decreases in CPAP level. Respiratory effort was measured with an oesophageal balloon. End-tidal CO(2 )tension (P(ET,CO(2))) was monitored with a nasal catheter. During trazodone nights, compared with placebo nights, the arousals occurred at a higher P(ET,CO(2)) level (mean+/-sd 7.30+/-0.57 versus 6.62+/-0.64 kPa (54.9+/-4.3 versus 49.8+/-4.8 mmHg), respectively). When arousals were triggered by increasing inspired CO(2) level, the maximal oesophageal pressure swing was greater (19.4+/-4.0 versus 13.1+/-4.9 cm H(2)O) and the oesophageal pressure nadir before the arousals was lower (-5.1+/-4.7 versus -0.38+/-4.2 cm H(2)O) with trazodone. When arousals were induced by stepwise CPAP drops, the maximal oesophageal pressure swings before the arousals did not differ. Trazodone at 100 mg increased the effort-related arousal threshold in response to hypercapnia in obstructive sleep apnoea patients and allowed them to tolerate higher CO(2) levels.

Patent foramen ovale and obstructive sleep apnoea: from pathophysiology to diagnosis of a potentially dangerous association.

Patent foramen ovale and obstructive sleep apnoea are frequently encountered in the general population. Owing to their prevalence, they may coexist fortuitously; however, the prevalence of patent foramen ovale seems to be higher in patients with obstructive sleep apnoea. We have reviewed the epidemiological data, pathophysiology, and the diagnostic and therapeutic options for both patent foramen ovale and obstructive sleep apnoea. We focus on the interesting pathophysiological links that could explain a potential association between both pathologies and their implications, especially on the risk of stroke.

Paediatric traffic accident and obstructive sleep apnoea by antrochoanal polyps: case report and literature review

Antrochoanal polyps are hyperplasias of the nasal mucosa, which have their origin in the maxillary sinus and extend through the nasal cavity and the choanae into the naso- and oropharynx. In children antrochoanal polyps represent one of the more frequent manifestations of paediatric nasal polyposis. Most studies on antrochoanal polyps in children report only on nasal obstruction, hyponasal speech and snoring, which are also encountered in the most common cause of obstructive sleep apnoea syndrome; i.e. adenoid or tonsillar hyperplasia. Only very few studies report on additional health hazards by antrochoanal polyps ranging from obstructive sleep apnoea syndrome to swallowing disorders and cachexia. We present the case of an 8 year old girl with a bicycle accident caused by excessive daytime sleepiness and obstructive sleep apnoea syndrome due to an extensive antrochoanal polyp. After a transnasal polypectomy and meatotomy type II the obstructive sleep apnoea and day time sleepiness resolved completely. Awareness of this additional health hazard is important and correct evaluation and timely diagnosis of a potential antrochoanal polyp is mandatory because minimally invasive rhinosurgery is highly curative in preventing further impending problems.

Recommendations for the management of patients with obstructive sleep apnoea and hypertension

This article is aimed at addressing the current state-of-the-art in epidemiology, pathophysiology, diagnostic procedures and treatment options for appropriate management of obstructive sleep apnoea (OSA) in cardiovascular (in particular hypertensive) patients, as well as for the management of cardiovascular diseases (in particular arterial hypertension) in OSA patients. The present document is the result of work performed by a panel of experts participating in the European Union COST (Cooperation in Scientific and Technological research) Action B26 on OSA, with the endorsement of the European Respiratory Society and the European Society of Hypertension. In particular, these recommendations are aimed at reminding cardiovascular experts to consider the occurrence of sleep-related breathing disorders in patients with high blood pressure. They are also aimed at reminding respiration experts to consider the occurrence of hypertension in patients with respiratory problems at night.

Sleepiness and performance is disproportionate in patients with non-organic hypersomnia in comparison to patients with narcolepsy and mild to moderate obstructive sleep apnoea.

BACKGROUND/AIMS Clinical differentiation between organic hypersomnia and non-organic hypersomnia (NOH) is challenging. We aimed to determine the diagnostic value of sleepiness and performance tests in patients with excessive daytime sleepiness (EDS) of organic and non-organic origin. METHODS We conducted a retrospective comparison of the multiple sleep latency test (MSLT), pupillography, and the Steer Clear performance test in three patient groups complaining of EDS: 19 patients with NOH, 23 patients with narcolepsy (NAR), and 46 patients with mild to moderate obstructive sleep apnoea syndrome (OSAS). RESULTS As required by the inclusion criteria, all patients had Epworth Sleepiness Scale (ESS) scores >10. The mean sleep latency in the MSLT indicated mild objective sleepiness in NOH (8.1 ± 4.0 min) and OSAS (7.2 ± 4.1 min), but more severe sleepiness in NAR (2.5 ± 2.0 min). The difference between NAR and the other two groups was significant; the difference between NOH and OSAS was not. In the Steer Clear performance test, NOH patients performed worst (error rate = 10.4%) followed by NAR (8.0%) and OSAS patients (5.9%; p = 0.008). The difference between OSAS and the other two groups was significant, but not between NOH and NAR. The pupillary unrest index was found to be highest in NAR (11.5) followed by NOH (9.2) and OSAS (7.4; n.s.). CONCLUSION A high error rate in the Steer Clear performance test along with mild sleepiness in an objective sleepiness test (MSLT) in a patient with subjective sleepiness (ESS) is suggestive of NOH. This disproportionately high error rate in NOH may be caused by factors unrelated to sleep pressure, such as anergia, reduced attention and motivation affecting performance, but not conventional sleepiness measurements.

Frequency of insomnia report in patients with obstructive sleep apnoea hypopnea syndrome (OSAHS)

Background and purpose: Insomnia and Obstructive Sleep Apnoea Hypopnea Syndrome (OSAHS) are the two most common sleep disorders, and both have significant associated health costs. Despite this, relatively little is known about the prevalence or impact of insomnia in those with OSAHS, although a recent study suggested there may be substantial comorbidity between these disorders [Chest 120 (2001) 1923-9]. The primary aim of this study was to further explore the prevalence of insomnia in OSAHS. A secondary aim was to assess the effect of factors that may impact on both conditions, including mood and sleep-beliefs. Patients and methods: Consecutive patients referred to an accredited Sleep Investigations Unit (n = 105) completed a brief standardized battery of validated questionnaires assessing sleep-related variables and mood. Results: Results showed a high rate of prevalence of clinical insomnia in this OSAHS population, and a strong positive correlation between OSAHS and insomnia symptom severity. Further, OSAHS patients with comorbid insomnia had increased levels of depression, anxiety and stress compared to patients with OSAHS-only, and both patient groups reported similar and significant levels of dysfunctional beliefs about sleep. Findings in relation to habitual sleep, assessed using subjective (diary) and objective criteria (polysomnogram), were mixed but generally showed greater sleep disturbance among those with OSAHS-insomnia compared to those with OSAHS-only. Conclusions: Overall these findings suggest that comorbidity of insomnia in OSAHS patients may lead to increased OSAHS severity and that patients with both conditions may experience more symptoms relating to depression, anxiety and stress. These findings underscore the need for insomnia assessment and management services, even in clinics that primarily service patients with OSAHS. (C) 2004 Elsevier B.V. All rights reserved.

Differentiating responses to obstructive sleep apnoea using pulse transit time

Conventional overnight polysomnography (PSG) used to determine the respiratory behaviour during sleep can be a complex and expensive procedure. Pulse transit time analysis (PTT) has shown potential to detect obstructive apnoeic and hypopnoeic events in adults. This study was undertaken to determine the potential of PTT to differentiate responses to upper airway obstruction. 103 obstructive respiratory events occurred in PSG studies performed on 11 children (10 male and 1 female, mean age 7.5years). PTT measurements were evaluated against the corresponding PSG results pre-scored by 2 blinded observers. Broadly, there were 2 types of responses. They can be either short period of rapid PTT decreases (Type 1) or prolonged but gradual PTT decreases (Type 2). Type 1 obstructive events showed a mean change of 51.77% (p

Classification of oximetry signals using Bayesian neural networks to assist in the detection of obstructive sleep apnoea syndrome

In the present study, multilayer perceptron (MLP) neural networks were applied to help in the diagnosis of obstructive sleep apnoea syndrome (OSAS). Oxygen saturation (SaO2) recordings from nocturnal pulse oximetry were used for this purpose. We performed time and spectral analysis of these signals to extract 14 features related to OSAS. The performance of two different MLP classifiers was compared: maximum likelihood (ML) and Bayesian (BY) MLP networks. A total of 187 subjects suspected of suffering from OSAS took part in the study. Their SaO2 signals were divided into a training set with 74 recordings and a test set with 113 recordings. BY-MLP networks achieved the best performance on the test set with 85.58% accuracy (87.76% sensitivity and 82.39% specificity). These results were substantially better than those provided by ML-MLP networks, which were affected by overfitting and achieved an accuracy of 76.81% (86.42% sensitivity and 62.83% specificity). Our results suggest that the Bayesian framework is preferred to implement our MLP classifiers. The proposed BY-MLP networks could be used for early OSAS detection. They could contribute to overcome the difficulties of nocturnal polysomnography (PSG) and thus reduce the demand for these studies.

Obstructive sleep apnoea is associated with sight threatening retinopathy and predicts the developement of preproliferative and proliferative retinopathy in patients with type 2 diabetes:a longitudinal analysis

troduct I on . An observational longitudinal study. P ur P ose . Assess the relationship between obstructive sleep apnoea (OSA) and DR cross-sectionally and longitudinally. M ethods . Adults with Type 2 diabetes mellitus (T2DM), who were re - cruited from a hospital-based diabetes clinic in the UK. Patients with pre-existing OSA, end-stage renal disease and non-diabetic retinopa - thy were excluded. OSA (apnoea hypopnea index ≥ 5 events/hour) was assessed by a single overnight home-based cardio-respiratory study (Alice PDX, Philips Respironics, USA). DR was assessed us - ing retinal images between 2007 and 2012. Sight threatening diabetic retinopathy (STDR) was defined as presence of pre-proliferative or proliferative DR, maculopathy or photocoagulation. Advanced DR was defined as pre-proliferative or proliferative DR. r esults . 199 patients were included (57.3% (n=114) men, 47.7% (n=95) White Europeans). STDR and OSA prevalence were 38.7% (n=77) and 62.8% respectively. A t b A sel I ne . STR prevalence was higher in patients with OSA (OSA+) compared to those without OSA (OSA-) [48.8% n=61 vs. 21.6% n=16, p<0.001]. After adjustment for confounders, OSA remained independently associated with STR (OR 3.7, 95% CI 1.6-8.9, p=0.006), maculopathy (OR 4.5, 95% CI 1.8-11.4, p=0.002) and advanced DR (OR 3.9, 95% CI 1.02-15.3, p=0.047). Mild and moderate to severe OSA were independently associated with STR and maculopathy and only moderate to severe OSA was associated with advanced DR following adjustment for con - founders. l ong I tud I n A lly . Over the follow-up period of (4.4±1 years), more OSA+ patients progressed from no or background DR to advanced DR (15.3% (n=17) vs. 3% (n=2), p=0.01). OSA was an independent pre - dictor of advanced DR development after adjustment for confounders (OR 6.6, 95% CI 1.2-35.1, p=0.03). OSA did not predict the develop - ment of maculopathy. c onclus I ons . OSA is independently associated with STR and predicts the development of preproliferative and proliferative DR. Intervention - al studies are needed to assess the impact of OSA treatment on DR.

Obstructive sleep apnoea predicts the development of preproliferative and proliferative retinopathy in patients with type 2 diabetes:a longitudinal analysis

Background and aims: Diabetic Retinopathy (DR) is a leading cause of blindness. OSA is associated with increased oxidative and nitrosative stress and endothelial dysfunction in patients with type 2 diabetes (T2DM). Hence, it is plausible that OSA can promote the development and progression of DR. Materials and methods: An observational longitudinal study in adults with T2DM. Patients with pre-existing OSA, end-stage renal disease and non-diabetic retinopathy were excluded. OSA (apnoea hypopnea index ≥ 5 events/hour) was assessed by a single overnight home-based cardio-respiratory monitoring (Alice PDX, etc.). DR was assesses using retinal images between 2007 and 2012. Sight threatening retinopathy (STR) was defined as pre-proliferative or proliferative DR, maculopathy or photocoagulation. Advanced DR was defined as pre-proliferative or proliferative DR. Results: 199 patients were included (57.3% men, 47.7% White Europeans). STR and OSA prevalence were 38.7 % and 62.8% respectively. STR preva-lence was higher in patients with OSA (OSA+) compared to those with-out (OSA-) [48.8% vs. 21.6%, p <0.001]. After adjustment for confounders, OSA remained independently associated with STR (OR 3.7, 95%CI 1.6-8.9, p=0.006, maculopathy (OR 4.5, 1.8-11.4, p=0.002) and advanced DR (OR 3.9, 1.02-15.3, p=0.047). Over 4.4±1 years, more OSA+ patients progressed from no or background DR to advanced DR (15.3% vs. 3%, p=0.01). OSA was an independent predictor of advanced DR development after adjustment (OR 6.6, 95%CI 1.2-35.1, p=0.03). OSA did not predict the development of maculopathy. Patients received continuous positive airway pressure treatment were less likely to develop advanced DR. Conclusion: OSA is independently associated with STR and predicts the development of preproliferative and proliferative DR. Interventional studies are needed to assess the impact of OSA treatment on DR.Supported by: NIHR (UK) and The UK Novo Nordisk Research Foundation.