Continuous positive airway pressure device-based automated detection of obstructive sleep apnea compared to standard laboratory polysomnography

Purpose

Obstructive sleep apnea (OSA) is a common health problem that affects more than 2–4% of the US population. Polysomnography (PSG) is the gold standard for diagnosing OSA. PSG is, however, expensive, time-consuming, and not always readily accessible. Hence, alternative diagnostic methods such as home-based testing have been evaluated. We studied the ability of the REMstar Pro (RSP2, a brand of continuous positive airway pressure (CPAP) device) to identify abnormal breathing events in subjects with OSA and compared this with breathing events simultaneously determined by laboratory-based PSG.

Methods

We evaluated 10 subjects previously diagnosed with OSA (apnea hypopnea index (AHI)?>?15, known therapeutic level of CPAP). Subjects underwent attended PSG using the REMstar Pro M series machine and their prescribed interface/mask type. The first 3 h of the study were conducted using a subtherapeutic CPAP (4 cm H2O). The last 3 h or remaining portion of the PSG was completed using the previously determined therapeutic CPAP. Comparison of respiratory events detected by PSG vs the RSP2 was performed.

Results

Subjects included four men and six women, aged 32 to 57 years and with a body mass index ranging from 29.5–66.4. The baseline AHI ranged from 18.3–93.1, with the AHI at therapeutic CPAP ranging from 0–3. Apnea counts at baseline and at therapeutic CPAP by manually scored PSG and REMstar were not significantly different (mean at subtherapeutic 11.7 vs 12.5, p?=?0.76; median at therapeutic CPAP 2.0 vs 4.5, p?=?0.15). Hypopnea counts at baseline and at effective CPAP by PSG and REMstar were not significantly different (mean at subtherapeutic 38.1 vs. 40.9, p?=?0.72; median at therapeutic CPAP 5.0 vs. 2.5, p?=?0.34). The correlation coefficient of REMstar and PSG for apnea and hypopnea was significant in subtherapeutic phase only (apnea r?=?0.78, p?=?0.007; hypopnea r?=?0.76, p?=?0.01). Agreement between the two methods declined for hypopnea detection at therapeutic CPAP.

Conclusions

The monitoring of residual sleep-disordered breathing on treatment, in addition to adherence, is an important objective therapeutic target in OSA. The REMstar Pro detects sleep-disordered breathing events similar to that of a manually scored PSG—for apnea but not for hypopnea—and merits further investigation as a device to determine disease severity and treatment efficacy.     

Risk assessment for CPAP nonadherence in adults with newly diagnosed obstructive sleep apnea: preliminary testing of the Index for Nonadherence to PAP (I-NAP)

Purpose

Identification of risk for continuous positive airway pressure therapy (CPAP) nonadherence prior to home treatment is an opportunity to deliver targeted adherence interventions. Study objectives included the following: (1) test a risk screening questionnaire to prospectively identify CPAP nonadherence risk among adults with newly diagnosed obstructive sleep apnea (OSA), (2) reduce the questionnaire to a minimum item set that effectively identifies 1-month CPAP nonadherence, and (3) examine the diagnostic utility of the screening index.

Methods

A prospective, longitudinal study at two clinical sleep centers in the USA included adults with newly diagnosed OSA (n?=?97; AHI ≥5 events/h) by polysomnogram (PSG) consecutively recruited to participate. After baseline participant and OSA characteristics were collected, a risk screening questionnaire was administered immediately following CPAP titration polysomnogram. One-month objective CPAP use was collected.

Results

Predominantly, white (87 %), males (55 %), and females (45 %) with obesity (BMI 38.3 kg/m²; SD 9.3) and severe OSA (AHI 36.8; SD 19.7) were included. One-month CPAP use was 4.25 h/night (SD 2.35). Nineteen questionnaire items (I-NAP) reliably identified nonadherers defined at <4 h/night CPAP use (Wald X ²[8]?=?34.67, p?60 % (63 %).

Conclusion

A risk screening questionnaire employed immediately after titration PSG may reliably identify CPAP nonadherers and permit the delivery of targeted interventions to prevent or reduce nonadherence. This novel approach may enhance cost-effectiveness of care and permit appropriate allocation of resources for CPAP adherence.     

Quantitative measurement of sleep quality using cardiopulmonary coupling analysis: a retrospective comparison of individuals with and without primary insomnia

Objective

The purpose of this study was to determine the utility of a new operator-independent, automated measure of sleep physiology based on cardiopulmonary coupling (CPC) analysis in subjects with primary insomnia vs. good sleepers.

Patients/methods

The polysomnograms of 50 subjects with primary insomnia and 36 good sleepers were summarized and analyzed from a consecutive two-night protocol. The electrocardiograms (ECG) from adaptation and baseline night polysomnograms were analyzed using CPC analysis. This Fourier-based technique uses heart rate variability and ECG R wave amplitude fluctuations associated with respiration to generate frequency maps of coupled autonomic–respiratory oscillations. The resulting sleep spectrogram is able to categorize sleep as “stable” (high-frequency coupling [HFC], 0.1–0.4 Hz) and “unstable” (low-frequency coupling [LFC], 0.1–0.01 Hz), independent of standard sleep stages. Wake and rapid eye movement sleep exhibit very low-frequency coupling (VLFC, 0.0039–0.01 Hz). Elevated LFC (e-LFC) is a subset of LFC that is associated with fragmented sleep of various etiologies.

Results

CPC variables showed a significant multivariate analysis of variance group, night, and group × night main effect, except for HFC by night. Relative to good sleepers, primary insomnia patients on adaptation night had lower HFC, a putative biomarker of stable sleep, and HFC/LFC ratio, an indicator of sleep quality. The primary insomnia group also had higher LFC, an index of unstable sleep, and an increase in VLFC and e-LFC compared to good sleepers on adaptation night. On baseline night, the primary insomnia group had increased LFC, VLFC, and e-LFC and a lower HFC/LFC ratio. Except for HFC, good sleepers had larger CPC variable differences between adaptation and baseline nights compared to the primary insomnia group.

Conclusion

Primary insomnia subjects have a marked worsening of sleep quality on the adaptation night, which is well captured by both conventional and ECG-derived sleep spectrogram techniques. The larger improvement of sleep quality was found among good sleepers and captured only by CPC analysis. The operator-independent, automated measure of sleep physiology demonstrated functionality to differentiate and objectively quantify sleep quality.     

Breathing irregularity during wakefulness associates with CPAP acceptance in sleep apnea

Purpose

Individuals have different breathing patterns at rest, during wakefulness, and during sleep, and patients with sleep apnea are no different. The hypothesis for this study was that breathing irregularity during wakefulness associates with CPAP acceptance in obstructive sleep apnea (OSA).

Methods

From a 2007–2010-database of patients with a diagnostic polysomnography (PSG) and prescribed CPAP (n?=?380), retrospectively, 66 patients who quit CPAP treatment at 6 months were identified. Among them, 27 OSA patients quit despite having no side effects for discontinuing CPAP (Group A) and were compared to a matched group (age, body mass index, and apnea–hypopnea index) with good 6-month CPAP adherence (Group B; n?=?21). Five minutes of respiratory signal during wakefulness at the initial PSG were extracted from respiratory inductance plethysmography recordings, and measured in a blinded fashion. The coefficients of variation (CV) for the breath-to-breath inspiration time (T _i), expiration time (T _e), T _i?+?T _e (T _tot), and relative tidal volume, as well as an independent information theory-based metric of signal pattern variability (mutual information) were compared between groups.

Results

The CV for tidal volume was significantly greater (p?=?0.001), and mutual information was significantly lower (p?=?0.041) in Group A as compared to Group B.

Conclusions

Differences in two independent measures of breathing irregularity correlated with CPAP rejection in OSA patients without nasal symptoms or comorbidity. Prospective studies of adherence should examine traits of breathing stability.     

Obstructive sleep apnea is common in patients with interstitial lung disease

Purpose

The incidence of obstructive sleep apnea (OSA) in interstitial lung disease (ILD) has been reported at different frequencies in several studies. The aims of our study were to evaluate the frequency of OSA in ILD and to analyze the relationship between polysomnography (PSG) findings and pulmonary function, disease severity, parenchymal involvement, and Epworth Sleepiness Scale (ESS) scores.

Methods

ILD patients with parenchymal involvement were evaluated. The disease severity was assessed using an index consisting of body mass index (BMI), carbon monoxide diffusion capacity, the Modified Medical Research Council dyspnea scale, and the 6-min walking distance. All of the patients had lung function, chest X-ray, PSG, ESS scoring, and an upper airway examination. Patients with a BMI?≥?30 or significant upper airway pathologies were excluded.

Results

Of 62 patients, 50 patients comprised the study group (14 male, 36 female; mean age 54?±?12.35 years, mean BMI 25.9?±?3.44 kg/m²) with diagnoses of idiopathic pulmonary fibrosis (IPF; n?=?17), stage II–III sarcoidosis (n?=?15), or scleroderma (n?=?18). The frequency of OSA was 68 %. The mean apnea–hypopnea index (AHI) was 11.4?±?12.5. OSA was more common in IPF patients (p?=?0.009). The frequency of rapid eye movement-related sleep apnea was 52.9 %. The frequency of OSA was higher in patients with a disease severity index ≥3 (p?=?0.04). The oxygen desaturation index and the AHI were higher in patients with diffuse radiological involvement (p?=?0.007 and p?=?0.043, respectively).

Conclusions

OSA is common in ILD. PSG or at minimum nocturnal oximetry should be performed, particularly in patients with functionally and radiologically severe disease.     

Reverse atrial electrical remodelling induced by continuous positive airway pressure in patients with severe obstructive sleep apnoea

Background

Obstructive sleep apnoea (OSA) is associated with cardiovascular morbidity and mortality, including atrial arrhythmias. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA; its impact on atrial electrical remodelling has not been fully investigated. Signal-averaged p-wave (SAPW) duration is an accepted marker for atrial electrical remodelling.

Objective

The objective of this study is to determine whether CPAP induces reverse atrial electrical remodelling in patients with severe OSA.

Methods

Consecutive patients attending the Sleep Disorder Clinic at Kingston General Hospital underwent full polysomnography. OSA-negative controls and severe OSA were defined as apnoea–hypopnea index (AHI)?<?5 events/hour and AHI?≥?30 events/hour, respectively. SAPW duration was determined at baseline and after 4–6 weeks of CPAP in severe OSA patients or without intervention controls.

Results

Nineteen severe OSA patients and 10 controls were included in the analysis. Mean AHI and minimum oxygen saturation were 41.4?±?10.1 events/hour and 80.5?±?6.5 % in severe OSA patients and 2.8?±?1.2 events/hour and 91.4?±?2.1 % in controls. At baseline, severe OSA patients had a greater SAPW duration than controls (131.9?±?10.4 vs 122.8?±?10.5 ms; p?=?0.02). After CPAP, there was a significant reduction of SAPW duration in severe OSA patients (131.9?±?10.4 to 126.2?±?8.8 ms; p?<?0.001), while SAPW duration did not change after 4–6 weeks in controls.

Conclusion

CPAP induced reverse atrial electrical remodelling in patients with severe OSA as represented by a significant reduction in SAPW duration.     

The effect of continuous positive airway pressure therapy on blood pressure and arterial stiffness in hypertensive patients with obstructive sleep apnea

Aim

We aimed to evaluate the effect of continuous positive airway pressure (CPAP) therapy on blood pressure (BP) and arterial stiffness in hypertensive patients with obstructive sleep apnea (OSA).

Patients and methods

We studied 38 hypertensive patients who suffered from severe OSA. Ambulatory BP measurement was performed at baseline and after at least 3 months of uninterrupted CPAP therapy. In 19 of these patients, we also measured pulse wave velocity (PWV) at baseline, after the first night of CPAP therapy and at 3 months. Fifteen normotensive subjects without OSA comprised the control group.

Results

CPAP therapy reduced systolic BP from 141.5?±?12.1 to 133.5?±?9.7 mmHg (p?=?0.007) and diastolic BP from 87.8?±?6.8 to 83?±?5.4 mmHg (p?=?0.004). CPAP also reduced the PWV from 8.81?±?1.4 to 8.18?±?1 m/s after the first night of CPAP therapy (p?=?0.003) and to 7.37?±?1 m/s at 3 months (p?=?0.007).

Conclusions

To the best of our knowledge, this is the first study demonstrating that CPAP therapy in hypertensive patients with OSA improves arterial stiffness from the first night and that this favorable effect is maintained for at least 3 months of CPAP use. A reduction in BP was also observed, even though BP control was not always achieved.     

The impact of sleep duration in obstructive sleep apnea patients

Purpose

Obstructive sleep apnea (OSA) is a risk factor for cardiovascular disease. Strong associations have been reported among sleep duration, hypertension, obesity, and cardiovascular mortality. The authors hypothesize that sleep duration may play a role in OSA severity. The aim of this study is to analyze sleep duration in OSA patients.

Methods

Patients who underwent overnight polysomnography were consecutively selected from the Sleep Clinic of Universidade Federal de São Paulo database between March 2009 and December 2010. All subjects were asked to come to the Sleep Clinic at 8:00 a.m. for a clinical evaluation and actigraphy. Anthropometric parameters such as weight, height, hip circumference, abdominal circumference, and neck circumference were also measured.

Results

One hundred thirty-three patients were divided into four groups based on total sleep time, sleep efficiency, sleep latency, and wake after sleep onset: very short sleepers (n?=?11), short sleepers (n?=?21), intermediate sleepers (n?=?56), and sufficient sleepers (n?=?45). Apnea–hypopnea index (AHI) was higher in very short sleepers (50.18?±?30.86 events/h) compared with intermediate sleepers (20.36?±?14.68 events/h; p?=?0.007) and sufficient sleepers (23.21?±?20.45 events/h; p?=?0.02). Minimal and mean arterial oxygen saturation and time spent below 90 % oxygen saturation exhibited worse values in very short sleepers. After adjustment for gender, age, AHI, and body mass index, mean oxygen saturation was significantly associated to total sleep time (p?=?0.01).

Conclusions

In conclusion, the present study suggests that sleep duration may be associated to low mean oxygen saturation in OSA patients.     

Factors associated with excessive daytime sleepiness in patients with severe obstructive sleep apnea

Purpose

Although excessive daytime sleepiness (EDS) is one of the key symptoms of obstructive sleep apnea (OSA), associations between OSA and EDS have been inconsistent, even in patients with severe OSA. To that end, our goal was to investigate factors associated with EDS based on the Epworth Sleepiness Scale (ESS) score in a large clinical population with severe OSA (apnea–hypopnea index ≥30).

Methods

This cross-sectional study included 1,126 consecutive adult patients referred for their first in-laboratory polysomnogram for suspicion of OSA. All patients completed a routine questionnaire including demographics, race, co-morbidities, sleep history, ESS, short-form quality of life questionnaire-12 (SF-12), the Center for Epidemiologic Studies Depression scale, and medications used. Severe OSA was diagnosed in 498 patients. After excluding patients taking narcotics, hypnotics, benzodiazepines, antidepressants, or those with diagnosis of depression, 355 patients remained in the final analytic cohort. Patients were divided into quartiles based on the ESS and comparisons were made between the lowest quartile (ESS?≤?6; n?=?105) and highest quartile (ESS?≥?13; n?=?97).

Results

Compared to the ESS?≤?6 group, patients in the ESS?≥?13 group had a significantly higher 3 % oxygen desaturation index and a significantly lower oxygen saturation nadir during sleep (p?<?0.05). Moreover, patients with severe OSA in the highest quartile of ESS had higher depressive symptomatology.

Conclusions

In patients with severe OSA, intermittent hypoxemia and depressive symptoms are important contributing factors to EDS.     

Impact of continuous positive airway pressure on C-reactive protein in patients with obstructive sleep apnea: a meta-analysis

Purpose

C-reactive protein (CRP) is associated with the development of obstructive sleep apnea (OSA) and cardiovascular diseases. Continuous positive airway pressure (CPAP) is an effective treatment for OSA, but the impact of CPAP therapy on CRP levels in patients with OSA remains unclear. To obtain this information, we performed a meta-analysis to determine whether effective CPAP therapy could reduce serum CRP levels.

Methods

A comprehensive literature search was performed to identify studies that examined the impact of CPAP on serum CRP levels in OSA patients who were treated with CPAP for at least 4 weeks. Standardized mean difference (SMD) was used to analyze the summary estimates for CPAP therapy.

Results

Fourteen self-control design studies involving 1199 patients with OSA met the inclusion criteria. Meta-analysis indicated that the overall SMD for the CRP levels was 0.64 units (95 % confidence interval (CI) 0.40 to 0.88) before and after CPAP therapy; test for overall effect z?=?5.27 (P?=?0.000). Subgroup analysis showed that evolution of CRP decreased non-significantly in less than 3 months (SMD, 0.26, 95 % CI ?0.08 to 0.60, P?=?0.138), significantly decreased after 3 months (SMD, 0.68, 95 % CI 0.34 to 1.02, P?=?0.000), and further declined after 6 months (SMD, 0.74, 95 % CI 0.43 to 1.05, P?=?0.000).

Conclusions

The systemic inflammation, as measured by CRP, was present and significantly reduced by effective CPAP therapy in patients with OSA. The use of CRP levels may be clinically recognized as a valuable predictor for OSA treatment monitoring.     

Assessment of the impact on compliance of a new CPAP system in obstructive sleep apnea

Background

Despite the efficacy of continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea (OSA), compliance with therapy remains suboptimal. The aim of this study was to determine whether the use of S9^TM increased compliance in established CPAP users.

Methods

Subjects with OSA (50) were recruited into the study. When subjects entered the study, 28 days of respective compliance data were downloaded from the patient's usual CPAP device. Subjects trialled the S9 CPAP for 28 days. Subjects then resumed use of their usual CPAP for 28 days. Compliance data from the patient's usual CPAP pre- and post-trialling S9 were compared with data from the S9 CPAP.

Results

Patients were significantly more compliant when using the S9 than their usual CPAP device both pre- and post-S9 based on average daily usage. CPAP pre-S9?=?6.58?±?1.95 (mean hours?±?SD), S9?=?7.08?±?1.18 h and CPAP post-S9?=?6.71?±?1.72 h. The difference between CPAP pre-S9 and S9 was 0.5 h (p?=?0.003). The difference between S9 and CPAP post-S9 was 0.35 h (p?=?0.01). There was no significant difference between CPAP pre-S9 and CPAP post-S9 (p?=?0.34). Patients also completed questionnaires comparing the S9 system to their usual device. Subjective feedback showed a strong preference for the S9.

Conclusions

Participants were significantly more compliant when using the S9 than their usual CPAP device both pre- and post-S9 use.     

Determinants of continuous positive airway pressure adherence in a sleep clinic cohort of South Florida Hispanic veterans

Purpose

There are little existing data on continuous positive airway pressure (CPAP) adherence in US Hispanic veterans with obstructive sleep apnea (OSA). Our aim was to describe determinants of 1-month adherence in a sleep clinic cohort of South Florida Hispanic veterans.

Methods

Hispanic veterans referred to the Miami VA sleep clinic were recruited and completed questionnaires about sleep apnea risk, sleep quality, insomnia symptoms, sleepiness, depression/anxiety, acculturation, personality traits, and cognitions about OSA and CPAP. Individuals at risk for OSA were scheduled for baseline polysomnography (PSG), followed by in-lab CPAP titration or a trial of auto-CPAP. Participants with OSA accepting CPAP therapy were asked to return after 7 and 30 days of treatment for adherence verification and to repeat questionnaires.

Results

One hundred twenty-four participants (94 % men) were enrolled with 114 completing overnight PSG. Eighty-six out of 95 participants (91 %) with sleep apnea syndrome or moderate to severe OSA accepted CPAP treatment. Fifty-nine participants completed both follow-up visits with a mean CPAP use at 30 days of 3.6?±?2.0 h. The only independent predictor of 7-day mean daily CPAP use was the baseline Insomnia Severity Index while the best predictor of 30-day mean daily CPAP use was the 7-day mean daily use.

Conclusions

Our study suggests that South Florida Hispanic veterans with OSA evaluated in a sleep clinic show poor CPAP adherence. Insomnia and poor early use predicted poor adherence overall. Larger prospective studies with other race–ethnic groups are needed to determine the role of ethnicity and race in CPAP adherence among US veterans with OSA.     

A fatty meal aggravates apnea and increases sleep in patients with obstructive sleep apnea

Purpose

The purpose of this study was to investigate the role of a fatty meal before bedtime, on sleep characteristics and blood pressure in patients with obstructive sleep apnea (OSA).

Methods

Recently diagnosed, by full polysomnography (PSG), patients with OSA (n?=?19) were included. These underwent PSG for additional two consecutive nights. Two hours before the PSG examination, a ham and cheese sandwich of 360 kcal was served to all patients, at first night, while a fatty meal of 1,800 kcal was served before the second PSG examination. Comparisons were performed between the last two examinations in terms of PSG data and morning and night blood pressure measurements.

Results

After the fatty meal, a significant increase was observed in total sleep time (p?=?0.026) in the Apnea–Hypopnea Index (AHI) (p?=?0.015), as well as in the absolute number of obstructive and central apneas (p?=?0.032 and p?=?0.042, respectively) compared to the previous night. Conversely, distribution of sleep stages and indices of nocturnal hypoxia (average and minimum SpO₂ and sleep time with SpO₂?<?90 %) did not change significantly. Likewise, no significant change was observed in blood pressure measurements.

Conclusions

Fatty meal intake before sleep can increase AHI in OSA patients, although it does not affect sleep architecture or indices of hypoxia.     

Comparison of a simple obstructive sleep apnea screening device with standard in-laboratory polysomnography

Background

Obstructive sleep apnea (OSA) is a common underdiagnosed sleep disorder. Various strategies have been employed to easily screen for OSA. The ApneaStrip® (AS - S.L.P. Ltd, Tel Aviv, Israel) is an FDA approved OSA screening device applied to the upper lip at home. We evaluated the performance of this device against simultaneous in-laboratory polysomnography (PSG) in a group of well-characterized OSA patients.

Methods

Diagnostic PSG was performed in 56 patients (29 M, 37 F; age 48.9?±?14.6 years; body mass index [BMI] 37.5?±?9.0 kg/m²; apnea-hypopnea index—events/h—[AHI] 32.8?±?22.9). The AS was applied and positioned to detect nasal and oral airflow. The AS gives a “positive” result for AHI?≥?15. We examined the sensitivity and specificity of the AS against three thresholds derived from PSG: AHI?≥?5, AHI?≥?15 (company recommendation), and AHI?≥?30.

Results

For PSG AHI?≥?15, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the AS were 80, 54.5, 87.8, and 40 %, respectively. For PSG AHI?≥?5, the values were 75.1, 66.7, 97.1, and 13.3 %, respectively. For PSG AHI?≥?30, the values were 86.9, 36.2, 48.8, and 80 %, respectively. There were no significant modifying effects of age, BMI, gender, hypertension, diabetes, lung disease, and heart disease.

Conclusion

The AS has a high sensitivity for detection of OSA with AHI?≥?15, but only modest specificity. The AS could be a useful component of an OSA screening program; however, negative results should be interpreted cautiously.

     

Mortality in middle-aged men with obstructive sleep apnea in Finland

Introduction

Obstructive sleep apnea (OSA) has been associated with an elevated rate of cardiovascular mortality. However, this issue has not been investigated in patients with elevated proneness to cardiovascular diseases. Our hypothesis was that OSA would have an especially adverse effect on the risk of cardiovascular mortality in Finnish individuals exhibiting elevated proneness for coronary heart diseases.

Methods

Ambulatory polygraphic recordings from 405 men having suspected OSA were retrospectively analyzed. The patients were categorized regarding sleep disordered breathing into a normal group (apnea hypopnea index (AHI)?<?5, n?=?104), mild OSA group (5?≤?AHI?<?15, n?=?100), and moderate to severe OSA group (AHI?≥?15, n?=?201). In addition, basic anthropometric and health data were collected. In patients who died during the follow-up period (at least 12 years and 10 months), the primary and secondary causes of death were recorded.

Results

After adjustment for age, BMI, and smoking, the patients with moderate to severe OSA suffered significantly (p?<?0.05) higher mortality (hazard ratio 3.13) than their counterparts with normal recordings. The overall mortality in the moderate to severe OSA group was 26.4 %, while in the normal group it was 9.7 %. Hazard ratio for cardiovascular mortality was 4.04 in the moderate to severe OSA and 1.87 in the mild OSA group.

Conclusions

OSA seems to have an especially adverse effect on the cardiovascular mortality of patients with an elevated genetic susceptibility to coronary heart diseases. When considering that all our patients had possibility of continuous positive airway pressure treatment and our reference group consisted of patients suffering from daytime somnolence, the hazard ratio of 4.04 for cardiovascular mortality in patients with moderate to severe disease is disturbingly high.     

Home-based diagnosis of obstructive sleep apnea by polysomnography type 2: accuracy,reliability, and feasibility

Purpose

Despite being used in large cohort studies, role of polysomnography (PSG) type 2 is still controversy. This study was aimed to determine its accuracy, reliability, and feasibility in diagnosis of obstructive sleep apnea (OSA) compared to gold standard.

Methods

Adult patients with stable medical conditions who complained of snoring or excessive sleepiness and lived around Bangkok were recruited from a sleep clinic. All were asked to fill questionnaires and have PSG done in laboratory (in-Lab PSG) and at home (Home PSG) on separate nights within 2–4 weeks interval.

Results

Eighty-six patients, 48 males and 38 females, were included. Mean of total sleep time, sleep efficiency, and stage R were significantly greater in Home PSG than in-Lab PSG (p?p?=?0.04), but with excellent reliability, intra-class correlation coefficients of 0.96 (95 % CI; 0.93–0.97), and good agreements (κ?=?0.59–0.70) between both tests. The sensitivity, specificity, and accuracy of Home PSG at cut-off point of AHI ≥5, were 0.97, 0.56, and 0.85, respectively, and at AHI ≥15 were 0.95, 0.76, and 0.85, respectively. Sixty-four patients (74.4 %) preferred home-PSG but four patients (4.7 %) needed repeated tests due to significant data loss.

Conclusions

This is the first report in Asia demonstrating that home-based diagnosis of OSA by PSG type 2 was feasible performing with good reliability, high accuracy, and a low failure rate. However, further studies focusing on its cost-effectiveness are required.     

Comorbid insomnia and sleep apnea in Veterans with post-traumatic stress disorder

Purpose

The purpose of this study was to determine the impact of insomnia in Veterans with post-traumatic stress disorder (PTSD) and obstructive sleep apnea (OSA) on health-related outcomes before and after 12 weeks of continuous positive airway pressure (CPAP) treatment.

Methods

We conducted a prospective cohort study of Veterans with PTSD and documented apnea hypopnea index (AHI) ≥?5 with and without clinically significant insomnia as determined by the Insomnia Severity Index (ISI). Health-related outcomes including PTSD checklist (PCL-M), SF-36, and Pittsburgh Sleep Quality Index (PSQI) were assessed at baseline and 12 weeks after initiation of OSA treatment. CPAP adherence was retrieved at each visit.

Results

Seventy-two Veterans including 36 with comorbid insomnia and OSA (COMISA) and 36 OSA-only were enrolled. Veterans with COMISA were younger (p?=?0.03), had lower BMI (p?<?0.001), and were more likely to report depression than those with OSA-only (p?=?0.004). Although AHI was higher in the COMISA (p?=?0.01), both groups expressed comparable daytime sleepiness (p?=?0.16). The COMISA group had no significant change in SF-36 and PSQI after 12 weeks of treatment and used CPAP much less frequently than OSA-only group (p?=?0.001).

Conclusions

COMISA in Veterans with PTSD is associated with worse quality of life than those with OSA-only. Insomnia should be assessed in Veterans with PTSD who are not adherent to CPAP treatment.

     

The effect of nightly nasal CPAP treatment on nocturnal hypoxemia and sleep disorders in mustard gas-injured patients

Introduction

Sleep-related breathing disorders are associated with unusual respiratory pattern or an abnormal reduction in gas exchange during sleep that is common in sulfur mustard (SM) exposure.

Methods

We compared 57 Iranian male patients injured with SM and had any complaints of sleep problems with an age-matched group of 21 Iranian male patients who had complaints of sleep problems and were not chemically injured; this group had Epworth Sleepiness Scale (ESS) above 10 and whom referred for polysomnography. Split-night studies were performed for patients with diagnostic polysomnography for obstructive sleep apnea (OSA) and respiratory events. We then studied respiratory events including episodes of OSA, apnea–hypopnea index (AHI) and respiratory disturbance index (RDI).

Results

The mean age in mustard-exposed patients was 48.14?±?8.04 years and in age-matched group, 48.19?±?8.39 years. In mustard exposed patients, there were statistical differences for the episodes of OSA (p?=?0.001), AHI (p?=?0.001), and RDI (p?=?0.001) between two segments of split-night studies. In the age-matched group, there were statistically differences for each parameter (episodes of OSA (p?=?0.001), AHI (p?=?0.001), and RDI (p?=?0.001)). There were no significant differences between two groups.

Conclusion

This study indicated that the incidence of respiratory events and nocturnal hypoxemia during sleep in mustard-exposed patients were high and treatment with CPAP significantly reduced all these events.     

Effects of obstructive sleep apnea severity on serum lipid levels in Greek children with snoring

Background

Although obstructive sleep apnea (OSA) is related to dyslipidemia in adults, limited data are available regarding its effects on serum lipids during childhood. Aim of this study was to assess the potential relationships between severity of OSA and cholesterol or triglyceride levels in a cohort of Greek children.

Methods

Data from children with snoring who underwent polysomnography and complete serum lipids measurements during a specified study period were analyzed retrospectively.

Results

Overall, obese children (n?=?261) had lower HDL cholesterol levels than non-obese subjects (n?=?113) (49.6?±?10.5 vs. 53.9?±?11.4 mg/dL; p?=?0.001) and higher triglyceride concentrations (69.8?±?32.2 vs. 63.2?±?27 mg/dL; p?=?0.041). Non-obese subjects with moderate-to-severe OSA did not differ in triglycerides, total, and LDL cholesterol concentrations but had lower HDL cholesterol, when compared to non-obese children with primary snoring/mild OSA (50.4?±?13.1 vs. 54.9?±?10.7 mg/dL; p?=?0.008). The risk for having low HDL cholesterol (??40 mg/dL) was threefold higher in non-obese subjects with moderate-to-severe OSA than in those with primary snoring/mild OSA, even after adjustment for age and gender [OR?=?3.44 (95% CI 1.44 to 8.24; p?=?0.006)]. Concentrations of serum lipids in obese children were not associated with severity of OSA. HDL cholesterol was 48.5?±?8.7 mg/dL in subjects with moderate-to-severe OSA and 50.0?±?11.1 mg/dL in children with primary snoring/mild OSA (p?=?0.519).

Conclusions

HDL cholesterol levels are inversely related to severity of OSA in non-obese children with snoring.     

The financial crisis has an impact in sleep medicine: experience of a sleep clinic in Greece

Objective

Greece has entered a long period of economic crisis with adverse effects in daily life. The aim of our study was to evaluate the impact of the economic crisis on the population visiting a sleep clinic between years 2008 and 2011.

Methods

Comparison of the number of patients, anthropometric data, symptoms, and treatment between 2008 (beginning of crisis) to 2011(great impact of crisis) was conducted.

Results

The number of patients significantly reduced in 2011(n?=?127) compared with that in 2008 (n?=?463) and 2009 (n?=?465). The mean age, body mass index, and Epworth Sleepiness Scale did not differ between the years (52.2?±?13.7 years, 33?±?7.4 kg/m², and 11.4?±?5.4, respectively). The main symptom of the patients was daytime sleepiness, and the symptoms that worsened in 2011 compared with 2008 were headaches (32.4 vs. 49.6 %, p?<?0.001) and nightmares (44 vs. 75.9 %, p?<?0.001). In 2008, 69.1 % of patients required treatment for obstructive sleep apnea syndrome with continuous positive airway pressure (CPAP), and 81.6 % of them received CPAP. In 2011, 67.7 % required treatment, but only 52.3 % received CPAP.

Conclusions

The economic crisis can be reflected in the number of patients, their symptoms and their treatment options.