Comparison of three actigraphic algorithms used to evaluate sleep in patients with obstructive sleep apnea

Purpose

Actigraphy is a non-invasive and valid method to detect sleep/wake status. However, the technique lacks reliability in patients with sleep-disordered breathing and its results may depend on the algorithm employed.

Methods

We compared three currently used algorithms (the Cole-Kripke, Sadeh, and University of California San Diego [UCSD]) and determined which is the most reliable in patients with obstructive sleep apnea (OSA) assessing total sleep time. After identification of the most reliable algorithm, we compared total sleep time with the severity of obstructive sleep apnea.

Results

The mean total sleep time was not significantly different from that yielded by polysomnography when the UCSD algorithm was employed (p?=?0.798) and UCSD algorithm was associated with the smallest bias. The correlation levels (with polysomnographic data) were mild-to-modest when the results yielded by all algorithms were evaluated, but were highest when the UCSD algorithm was employed (UCSD, r?=?0.498, p?<?0.001; Cole-Kripke, r?=?0.389, p?<?0.01; Sadeh, r?=?0.272, p?=?0.057). Actigraphic measures of mean total sleep time underestimated sleep in patients with severe obstructive sleep apnea (apnea–hypopnea index [AHI] ≥30), and the correlation was low (r?=?0.317, p?=?0.116), but overestimated sleep, with high correlations, in patients with mild (5?≤?AHI?<?15) and moderate OSA (15?≤?AHI?<?30; r?=?0.859, p?<?0.001; r?=?0.842, p?<?0.001, respectively).

Conclusions

Among the three actigraphic algorithms tested in this study, sleep duration estimated by the UCSD algorithm was the most correlated with polysomnography data in an OSA population. However, none of them was reliable enough for estimating sleep time in patients with sleep-disordered breathing, especially in patients with severe OSA.     

Complete denture wear during sleep in elderly sleep apnea patients—a preliminary study

Objectives

There is no consensus in the literature about the impact of complete denture wear on obstructive sleep apnea (OSA). The goal of this randomized clinical study was to assess if complete denture wear during sleep interferes with the quality of sleep.

Materials and methods

Elderly edentulous OSA patients from a complete denture clinic were enrolled and received new complete dentures. An objective sleep analysis was determined with polysomnography performed at the sleep laboratory for all patients who slept either with or without their dentures.

Results

Twenty-three patients (74% females) completed the study with a mean age of 69.6?years and a mean body mass index of 26.7?kg/m². The apnea and hypopnea index (AHI) was significantly higher when patients slept with dentures compared to without (25.9?±?14.8/h vs. 19.9?±?10.2/h; p?>?0.005). In the mild OSA group, the AHI was significantly higher when patients slept with the dentures (16.6?±?6.9 vs. 8.9?±?2.4; p?p?=?0.2). The supine AHI in mild patients was related to a higher increase in AHI while wearing dentures (12.7?±?8.4/h vs. 51.9?±?28.6/h; p?Conclusions Contrary to previous studies, we found that OSA patients may experience more apneic events if they sleep with their dentures in place. Specifically, in mild OSAS patients, the use of dentures substantially increases the AHI especially when in the supine position.     

The effect of non-benzodiazepine hypnotics on sleep quality and severity in patients with OSA: a meta-analysis

Purpose

Although there is a high co-occurrence of insomnia and obstructive sleep apnea (OSA), the administration of sedative hypnotics in patients with OSA is still inconsistent. The aim is to study the effect of non-benzodiazepine hypnotics (non-BZDs) on sleep quality and severity in patients with OSA.

Methods

We conducted a systemic search for controlled clinical trials in multiple databases and pooled analysis of the impact of non-BZDs on objective sleep quality and the severity of OSA, including the apnea-hypopnea index (AHI) and mean and nadir arterial oxygen saturation (SaO₂) in patients with OSA. Sensitivity analysis was carried out to explore the robustness of results.

Results

Eight relevant placebo-controlled clinical trials involving 448 patients were included. Objective sleep quality, including sleep latency, sleep efficiency, and wake time after sleep onset, was significantly improved in patients taking non-BZDs compared with those taking placebo (p?2 in OSA patients (p?>?0.05).

Conclusions

The administration of non-BZDs at the commonly recommended dose has been shown to improve objective sleep quality in OSA patients without worsening sleep apnea. It suggests that OSA patients with a complaint of insomnia symptoms may benefit from taking non-BZDs.     

Positional sensitivity as a confounder in diagnosis of severity of obstructive sleep apnea

Purpose

The apnea–hypopnea index (AHI) is used to grade obstructive sleep apnea (OSA) into mild, moderate, and severe forms. Obstructive events are most common in the supine position. The amount of supine sleep thus influences total AHI. Our aim was to determine the prevalence of position-dependent OSA (POSA) and its relation to OSA severity classification as recommended by the American Academy of Sleep Medicine (AASM).

Methods

Two hundred sixty-five subjects were recruited from primary care hypertension clinics. Whole-night respiratory recordings were performed to determine the AHI in the supine and non-supine positions, respectively. POSA was defined as supine AHI twice the non-supine AHI with supine AHI ≥5.

Results

Fifty-three percent had POSA, 22% had non-position-dependent OSA, and 25% had normal respiration. By AASM classification, 81 subjects did not have OSA, but 42% of them had some degree of obstruction when supine, and 5 subjects would have been classified as moderate–severe if they had only slept supine. Conversely, of the 53 classified as mild OSA, 30% would have changed to a more severe classification if they had exclusively slept supine.

Conclusions

POSA was common both in subjects that by AASM classification had OSA as well as those without. The severity of OSA, as defined by AASM, could be dependent on supine time in a substantial amount of subjects.     

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.     

Severity of obstructive sleep apnea is associated with elevated plasma fibrinogen in otherwise healthy patients

Purpose

Obstructive sleep apnea (OSA) has been implicated in both cardiovascular and cerebrovascular diseases. Systemic inflammation and coagulation may be related to cardiovascular pathophysiology in patients with OSA. Fibrinogen is a major coagulation protein associated with inflammation, and long-term elevated plasma fibrinogen is associated with an increased risk of major cardiovascular diseases. We assessed whether severity of OSA is associated with levels of fibrinogen in newly diagnosed, untreated, and otherwise healthy OSA patients.

Methods

We studied 36 men with OSA and 18 male control subjects (apnea–hypopnea index [AHI] <5 events/h). OSA patients were divided into mild (AHI ≥5?Results Fibrinogen levels were significantly elevated in patients with severe OSA compared to both control (P?=?0.003) and mild OSA (P?=?0.02) subjects after adjustment for covariates. However, there were no significant differences in fibrinogen levels between mild OSA and control subjects. Fibrinogen levels were directly related to AHI and arousal index and inversely related to mean and lowest oxygen saturation during sleep.

Conclusions

Severity of OSA was associated with increased fibrinogen level independent of other factors, suggesting that apneic events and oxygen desaturation during sleep are mechanisms for increased fibrinogen levels in patients with OSA.     

Postoperative complications in obstructive sleep apnea

Study objectives

This study was conducted to determine whether postoperative complications are increased in patients with obstructive sleep apnea (OSA) and to study the impact of the severity of OSA and preoperative use of continuous positive airway pressure (CPAP) on the postoperative outcome.

Design and setting

This study is retrospective in nature and was undertaken at the VA Medical Center.

Participants and methods

Three hundred seventy patients who had undergone both a major surgical procedure and a sleep study from 2000 to 2010 were identified. Patients were divided into four groups: OSA negative (apnea–hypopnea index (AHI)?<?5/h), OSA positive; mild: AHI 5 to <15/h; moderate: AHI 15 to <30/h; and severe: AHI?≥?30/h. No intervention was made during the course of the study. Postoperative complications namely respiratory, cardiac, neurological, and unplanned intensive care unit transfers were collected.

Results

There were 284 (76.8 %) patients having OSA and 86 (23.2 %) without OSA. The overall incidence of total complications was significantly higher in the OSA patients compared with the control patients (48.9 vs. 31.4 %; odds ratio 2.09, 95 % CI 1.25–3.49). There was no significant difference in total complications between those using and not using CPAP prior to hospitalization. Patients with sleep apnea had a higher incidence of respiratory complications compared to patients without sleep apnea (40.4 vs. 23.2 %; odds ratio 2.24, 95 % CI 1.29–3.90). There was no significant difference in major cardiac complications in the OSA patients compared with the control patients (13.0 vs. 9.3 %; odds ratio 1.46, 95 % CI 0.65–3.26).

Conclusion

OSA is associated with a significantly increased rate of postoperative complications.     

Subjective sleepiness and daytime functioning in bariatric patients with obstructive sleep apnea

Purpose

The purpose of this study was to evaluate associations between obstructive sleep apnea (OSA) severity and self-reported sleepiness and daytime functioning in patients considering bariatric surgery for treatment of obesity.

Methods

Using a retrospective cohort design, we identified 342 patients who had sleep evaluations prior to bariatric surgery. Our final sample included 269 patients (78.6 % of the original cohort, 239 females; mean age?=?42.0?±?9.5 years; body mass index?=?50.2?±?7.7 kg/m²) who had overnight polysomnography and completed the Epworth Sleepiness Scale (ESS) and the Functional Outcomes of Sleep Questionnaire (FOSQ). Patients' OSA was classified as none/mild (apnea–hypopnea index (AHI)?<?15, n?=?112), moderate (15?≤?AHI?<?30, n?=?77), or severe (AHI?≥?30, n?=?80). We calculated the proportion of unique variance (PUV) for the five FOSQ subscales. ANOVA was used to determine if ESS and FOSQ were associated with OSA severity. Unpaired t tests compared ESS and FOSQ scores in our sample with published data.

Results

The average AHI was 29.5?±?31.5 events per hour (range?=?0–175.8). The mean ESS score was 6.3?±?4.8, and the mean global FOSQ score was 100.3?±?18.2. PUVs for FOSQ subscales showed moderate-to-high unique contributions to FOSQ variance. ESS and global FOSQ score did not differ by AHI group. Only the FOSQ vigilance subscale differed by OSA severity with the severe group reporting more impairment than the moderate and none/mild groups. Our sample reported less sleepiness and daytime impairment than previously reported means in patients and controls.

Conclusions

Subjective sleepiness and functional impairment were not associated significantly with OSA severity in our sample of patients considering surgery for obesity. Further research is needed to understand individual differences in sleepiness in patients with OSA. If bariatric patients underreport symptoms, self-report measures are not an adequate substitute for objective assessment and clinical judgment when evaluating bariatric patients for OSA. Patients with severe obesity need evaluation for OSA even in the absence of subjective complaints.     

Effects of tonsillectomy on sleep study parameters in adult patients with obstructive sleep apnea—a prospective study

Objective

The objective of this study is to evaluate the efficacy of tonsillectomy in reduction of respiratory disturbance index (RDI) and other sleep study parameters in patients with obstructive sleep apnea (OSA).

Methods

This study involves 34 adults with OSA and Friedman grade 3 or 4 tonsils. All 34 patients were treated with tonsillectomy, as the only surgical treatment for OSA from 2007 to 2011. Pre- and postoperative polysomnography were performed in all these patients.

Results

Prior to tonsillectomy, 21 patients had severe, 9 had moderate, and 4 had mild OSA. Surgical response rate (defined as 50 % or more reduction in apnea–hypopnea index (AHI) and a postoperative AHI of less than 20) was 71.4 % among patients with severe OSA, 77.7 % among patients with moderate, and 75 % among patients with mild. Among all the 34 patients, there was a reduction of 24.6 (p?=?0.000) in the RDI postoperatively. In our sub-analysis, we arbitrarily divided the patients into three groups: patients with RDI less than 30, patients with RDI between 30 and 60, and patients with RDI above 60. It showed that, in the group with RDI >60, an average reduction of RDI by 57.6 (p?=?0.000) was achieved and was the greatest reduction in RDI.

Conclusions

Tonsillectomy alone may be considered as an effective first line surgical procedure in the treatment of OSA in selected patients. Patients with Friedman grade 3 or 4 tonsils may be considered for tonsillectomy as the initial surgical procedure, reserving other upper airway procedures at a later stage if necessary.     

Lateral cephalometric analysis and the risks of moderate to severe obstructive sleep-disordered breathing in Thai patients

Purposes

This cross-sectional study was aimed to compare lateral cephalometric parameters among patients with different severities of obstructive sleep-disordered breathing and to determine if there are radiographic variables that increase risk of moderate to severe obstructive sleep apnea (OSA).

Methods

Ten linear and 5 angular parameters of lateral cephalometry in 188 adult subjects which included 47 controls and 141 patients with OSA classified by apnea–hypopnea index (AHI) from level-I polysomnography, were analyzed. All radiographs were done under standardized processes and measured twice on separate occasions.

Results

There were statistically significant differences between controls and patients with AHI?≥?15 in parameters such as a distance from mandibular plane to hyoid (MP-H), posterior airway space (PAS), skull base angle (NSBA), a distance from posterior nasal spine to posterior pharyngeal wall (PNS-PP), and soft palate length (PNS-P), (p?<?0.01). However, no significant difference was found between controls and mild OSA. Logistic regression analysis showed that only MP-H with cutoff point of?≥?18 millimeters, NSBA?≤?130°, and PAS?≤?10 millimeters were independent cephalometric variables that increased risk of having AHI?≥?15 compared to controls with adjusted odds ratio of 17.1, 8.3 and 4.2, respectively. Gender did not significantly associate with OSA severity in this analysis.

Conclusions

Patients who had longer MP-H, narrower PAS and narrower NSBA than specific cutoff points significantly increased risks of moderate to severe OSA. Treatments that effectively improve these parameters, particularly at tongue base level (MP-H and PAS), may decrease the severity of disease.     

Nocturnal hypoxemia biomarker predicts sleepiness in patients with severe obstructive sleep apnea

Purpose

This study aims to assess the association between excessive daytime sleepiness (EDS) and variables extracted from the pulse-oximetry signal obtained during overnight polysomnography.

Methods

A cross-sectional design was used to study the relation between four hypoxemia variables and EDS as determined by Epworth Sleepiness Scale scores (ESSS) in 200 consecutive patients, newly diagnosed with obstructive sleep apnea (OSA), as defined by an apnea–hypopnea index (AHI)?≥?15. Hypoxemia measurements were compared between sleepy (ESSS?≥?10) and nonsleepy (ESSS?<?10) patients before and after dichotomizing the cohort for each hypoxemia variable (and for AHI) such that there were 35 (165) patients in each of the corresponding higher (lower) subcohorts. The hypoxemia variables were combined into a biomarker, and its accuracy for predicting sleepiness in individual patients was evaluated. We planned to interpret prediction accuracy above 80 % as evidence that hypoxemia predicted EDS.

Results

Hypoxemia was unassociated with sleepiness in OSA patients with AHI in the range of 15 to 50. In patients with AHI?>?50, the hypoxemia biomarker (but not individual hypoxemia variables) predicted sleepiness with 82 % accuracy.

Conclusion

Nocturnal hypoxemia as determined by a polyvariable biomarker reliably predicted EDS in patients with severe OSA (AHI?>?50), indicating that oxygen fluctuation had a direct role in the development of EDS in patients with severe OSA.     

Gender and age influence the effects of slow-wave sleep on respiration in patients with obstructive sleep apnea

Introduction

Obstructive sleep apnea (OSA) is influenced by sleep architecture with rapid eye movement (REM) sleep having the most adverse influence, especially in women. There is little data defining the influence of slow-wave sleep (SWS) on OSA. We wished to study the influence of SWS on OSA and identify differences attributable to gender and/or age, if any.

Methods

Retrospective study of polysomnography (PSG) records of adult patients referred for diagnostic PSG. Records were excluded if they underwent split night or positive airway pressure titration studies, had <180 min of total sleep time (TST) and/or <40% sleep efficiency, or had SWS <5 min and/or <1% of TST. The apnea–hypopnea index (AHI) recorded during SWS was compared with that measured during other non-rapid eye movement (NREM) sleep and during REM sleep. The REM–SWS difference in AHI was measured, and compared between genders.

Results

Records from 239 patients were included. The mean AHI in all subjects was 17.7?±?22.6. The SWS AHI was 6.8?±?18.9, compared to the REM AHI of 24.9?±?25.8, and NREM AHI of 15.8?±?22.8. Females had significantly higher SWS by percentage, and lower NREM AHI (P?<?0.0001) and SWS AHI (P?=?0.03). Among patients with OSA (AHI ≥5), the difference between REM AHI and SWS AHI was greater in women than in men (34.2?±?27.4 vs. 21.6?±?26.0, P?=?0.006).

Conclusions

The upper airway appears to be less susceptible to OSA during SWS than during REM and other NREM sleep. This may be related to phase-specific influences on both dynamic upper airway control as well as loop gain. Gender and age appear to modify this effect.     

Measurement of dyspnea in patients with obstructive sleep apnea

Purpose

Patients with obstructive sleep apnea (OSA) frequently complain of exertional dyspnea. We aimed to assess its related factors and the significance of its measurement in OSA.

Methods

We evaluated 301 subjects with suspected OSA for dyspnea during activities of daily living using the Medical Research Council (MRC) scale. We analyzed the relationships between MRC grades and various subjective and objective indices. Further, the relationship of disease severity based on the apnea/hypopnea index (AHI) with these indices was examined. Results were compared between those obtained using MRC grades and the AHI.

Results

Of 301 subjects, 265 were diagnosed with OSA. Their MRC scores were worse than in non-OSA patients. Among OSA patients, 125 had MRC grade 1 (mild), 121 had MRC grade 2 (moderate), and 19 had MRC grade 3 or more (severe) dyspnea. Various measurements differed significantly between groups categorized according to the MRC scale although determinants between mild and moderate groups and between moderate and severe groups differed. AHI categorizations were not significantly related to patient-reported measurements such as the Medical Outcomes Study 36-item short form, Pittsburgh Sleep Quality Index, and Hospital Anxiety and Depression Scale scores, unlike categorization based on the MRC scale.

Conclusions

Dyspnea is an important outcome in OSA although dyspnea in OSA patients is unrelated to the sleep disorder per se. Measurement of dyspnea in patients with OSA might provide further insights into the health of these patients and clinical manifestations of this disease.     

High prevalence of obstructive sleep apnea in patients with resistant paroxysmal atrial fibrillation after pulmonary vein isolation

Objectives

To address the question whether obstructive sleep apnea (OSA) is associated with the recurrence of paroxysmal atrial fibrillation (AF) in patients treated with ≥2 pulmonary vein isolation procedures.

Patients and Methods

In this study, we included adults with therapy-resistant symptomatic paroxysmal AF, defined as AF recurring after ≥2 PV-isolation procedures (n?=?23). For comparison, we selected another cohort of patients being successfully treated by one PV isolation without AF recurrence within 6 months (n?=?23). PV isolation was performed by radiofrequency with an open irrigated tip catheter. Each of the 46 participants completed an overnight polygraphic study. The two groups were matched for age, gender, and ejection fraction. Patients were late middle-aged (65?±?7 vs 63?±?10 years, P?=?0.23), white (100%), and overweight (BMI 27.3?±?3.6 vs. 27.2?±?4.6 kg/m², P?=?0.97).

Results

The prevalence of sleep apnea, defined as an apnea–hypopnea index (AHI) of >5 per hour of sleep, was 87% in patients with therapy-resistant AF compared to 48% in the control cohort (P?=?0.005). In addition, OSA was more severe in the resistant AF group indicated by a significantly higher AHI (27?±?22 vs 12?±?16, P?=?0.01).

Conclusion

The extraordinarily high prevalence of sleep apnea in patients with recurrent paroxysmal AF supports its presumable role in the pathogenesis of AF and demands further controlled prospective trials. Moreover, OSA should inherently be considered in patients with therapy-resistant AF.     

Treatment of obstructive sleep apnea using a custom-made titratable duobloc oral appliance: a prospective clinical study

Purpose

This prospective clinical study investigates the efficacy of a specific custom-made titratable mandibular advancement device (MAD) for the treatment of obstructive sleep apnea (OSA). This MAD has attachments in the frontal teeth area that allow for progressive titration of the mandible.

Methods

Sixty-one adult OSA patients were included (age, 46.7?±?9.0 years; male/female ratio, 45/16; apnea–hypopnea index (AHI), 23.2?±?15.4 events/h sleep; body mass index, 27.9?±?4.1 kg/m²). After an adaptation period, titration started based on a protocol of symptomatic benefit or upon reaching the physiological limits of protrusion. As a primary outcome, treatment response was defined as an objective reduction in AHI following MAD treatment of ≥50 % compared to baseline, and treatment success as a reduction in AHI with MAD to less than 5 and 10 events/h sleep. Compliance failure was defined as an inability to continue treatment.

Results

A statistically significant decrease was observed in AHI, from 23.4?±?15.7 at baseline to 8.9?±?8.6 events/h with MAD (p?<?0.01). Treatment response was achieved in 42 out of 61 patients (68.8 %), whereas 42.6 % met criteria of AHI?<?5 and 63.9 % achieved an AHI?<?10 events/h sleep, respectively. Four patients (6.6 %) were considered as “compliance failures.”

Conclusions

The present study has evaluated the efficacy of a specific custom-made titratable MAD in terms of sleep apnea reduction.     

An electrocardiogram-based analysis evaluating sleep quality in patients with obstructive sleep apnea

Objective

The study compares polysomnography (PSG) and cardiopulmonary coupling (CPC) sleep quality variables in patients with (1) obstructive sleep apnea (OSA) and (2) successful and unsuccessful continuous positive airway pressure (CPAP) response.

Patients/methods

PSGs from 50 subjects (32 F/18 M; mean age 48.4?±?12.29 years; BMI 34.28?±?9.33) were evaluated. OSA patients were grouped by no (n?=?16), mild (n?=?13), and moderate to severe (n?=?20) OSA (apnea–hypopnea index (AHI)?≤?5, >5–15, >15 events/h, respectively). Outcome sleep quality variables were sleep stages in non-rapid eye movement, rapid eye movement sleep, and high (HFC), low (LFC), very low-frequency coupling (VLFC), and elevated LFC broad band (e-LFC_BB). An AHI?≤?5 events/h and HFC?≥?50 % indicated a successful CPAP response. CPC analysis extracts heart rate variability and QRS amplitude change that corresponds to respiration. CPC-generated spectrograms represent sleep dynamics from calculated coherence product and cross-power of both time series datasets.

Results

T tests differentiated no and moderate to severe OSA groups by REM % (p?=?0.003), HFC (p?=?0.007), VLFC (p?=?0.007), and LFC/HFC ratio (p?=?0.038) variables. The successful CPAP therapy group (n?=?16) had more HFC (p?=?0.003), less LFC (p?=?0.003), and e-LFC_BB (p?=?0.029) compared to the unsuccessful CPAP therapy group (n?=?8). PSG sleep quality measures, except the higher arousal index (p?=?0.038) in the unsuccessful CPAP group, did not differ between the successful and unsuccessful CPAP groups. HFC?≥?50 % showed high sensitivity (77.8 %) and specificity (88.9 %) in identifying successful CPAP therapy.

Conclusions

PSG and CPC measures differentiated no from moderate to severe OSA groups and HFC?≥?50 % discriminated successful from unsuccessful CPAP therapy. The HFC?≥?50 % cutoff showed clinical value in identifying sleep quality disturbance among CPAP users.     

Home sleep study characteristics in patients with mucopolysaccharidosis

Background

Mucopolysaccharidoses (MPS) are a group of inherited lysosomal storage disorders caused by the deficiency of hydrolases involved in the degradative pathway of glycosaminoglycans. In MPS, upper airway obstruction may result from multiple causative factors which may impact severely upon morbidity and mortality.

Methods

We evaluated upper airway obstructive disease and related clinical findings through home sleep study in 19 patients (11 with MPS VI, 4 with MPS I, 4 with MPS II) with MPS followed at Gazi University Pediatric Metabolic Unit. Patients underwent home-based sleep measurements, and sleep respiratory problems were asked in a detailed clinical history. Measurements of apnea, apnea–hypopnea index (AHI), hypopnea index, oxygen desaturation index, and minimal oxygen saturation were obtained through home sleep study.

Results

For 19 children, the disorder was normal in 1, mild (AHI?=?1.5–5/h) in 5, moderate (AHI?=?5–10/h) in 2, and severe (AHI?>?10/h) in 11. The prevalence of OSA was 94.7 % (18/19) in patients with MPS. Snoring, witnessed apnea, pectus carinatum, and macroglossia were the main clinical findings. Echocardiograms showed evidence of pulmonary hypertension in 13 patients.

Conclusion

Home sleep study is a quick and accessible screening test to determine the abnormalities of breathing during sleep and enables clinicians to take necessary action for patients with severe manifestations.     

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.     

Obstructive sleep apnea and acute myocardial infarction severity: ischemic preconditioning?

Background

Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia (IH). In animal models, IH has been shown to protect the myocardium during periods of ischemia by reducing infarct size. However, this phenomenon of “ischemic preconditioning” has not been investigated among OSA patients with acute myocardial infarction (MI). This study investigates the role of OSA on MI severity as measured by cardiac enzymes, specifically troponin-T, among patients with an acute MI.

Methods

This is an observational cohort study of patients ≥18 years of age who were hospitalized with an acute MI. Each participant underwent portable sleep monitoring (Apnea Link Plus); OSA was defined as an apnea–hypopnea index ≥5/h. Multivariable regression analysis was conducted to assess the relationship between OSA and highly sensitive troponin-T levels.

Results

In our entire cohort of acute MI patients (n?=?136), 77 % of the sample had evidence of sleep disordered breathing, with 35 % of the sample having OSA (i.e., an AHI >5). Higher AHI was associated with lower peak troponin-T levels in partially adjusted models (β?=??0.0320, p?=?0.0074, adjusted for age, gender, and race) and fully adjusted models (β?=??0.0322, p?=?0.0085) (additionally adjusted for smoking, hypertension, hyperlipidemia, body mass index, history of prior cardiovascular or cerebrovascular disease, diabetes and baseline admission creatinine levels). The mean value of the log-transformed peak troponin-T variable was used to dichotomize the outcome variable. In both partially (OR 0.949, CI 0.905–0.995, p?=?0.03) and fully adjusted (OR 0.918, CI 0.856–0.984, p?=?0.0151) logistic regression models, the OR for AHI suggests a protective effect on high troponin-T level.

Conclusions

Our study demonstrates that patients with OSA have less severe cardiac injury during an acute non-fatal MI when compared to patients without OSA. This may suggest a cardioprotective role of sleep apnea during acute MI via ischemic preconditioning.     

Correlation of daytime sleepiness with urine metabolites in patients with obstructive sleep apnea

Purpose

The apnea–hypopnea index (AHI) is closely related with the severity of daytime sleepiness, but excessive daytime sleepiness (EDS) is not presented on all patients with obstructive sleep apnea (OSA). It is unclear why daytime sleepiness is not always present in OSA patients even if their sleep is disrupted from the perspective of polysomnographic findings. This study aimed to analyze the correlation between sleepiness and urine metabolites of neurotransmitters involved in the arousal system.

Methods

On the basis of AHI in polysomnography, 49 consecutive OSA patients were included. According to their Epworth sleepiness scale (ESS), 23 non-sleepy patients (ESS <11) and 26 sleepy patients (ESS ≥11) were included. Urine samples were collected before and after polysomnography and analyzed by gas chromatography–mass spectrometry with selective ion monitoring. Six metabolites of dopamine, norepinephrine and serotonin were analyzed.

Results

The dopamine metabolites, homovanillic acid (r?=?0.366, P?=?0.017) and 3,4-dihydroxyphenylacetic acid (DOPAC; r?=?0.584, P?P?=?0.032).

Conclusion

Urine dopamine metabolites may identify sleepy patients with OSA. In particular, the overnight change of urine DOPAC may indicate OSA patients with EDS.