Showing papers in "Sleep and Breathing in 2005"
TL;DR: Treatment with CPAP leads to a clinically significant drop in HbA1c in patients with type 2 diabetes mellitus and severe OSA, and this hypothesis is supported by a retrospective analysis of patients seen in the sleep clinic of an urban public teaching hospital.
Abstract: Obstructive sleep apnea (OSA) is independently associated with glucose intolerance and insulin resistance, and recent studies have shown that continuous positive airway pressure (CPAP) improves insulin sensitivity. The objective of this study was to describe the change in glycosylated hemoglobin (HbA1c) after treatment with CPAP in patients with type 2 diabetes mellitus and OSA. To test this hypothesis, we performed a retrospective analysis of 38 patients seen in the sleep clinic of an urban public teaching hospital. All patients had OSA and type 2 diabetes mellitus, and their diabetic medication regimen had remained unchanged during the period of CPAP therapy. Sixty-one percent were men, body mass index was 42±9.5 kg/m2, and the Apnea–Hypopnea Index was 53±36 per hour. HbA1c before therapy with CPAP was 7.8±1.4% and decreased to 7.3±1.3% after 134±119 days of therapy (p<0.001). Treatment with CPAP leads to a clinically significant drop in HbA1c in patients with type 2 diabetes mellitus and severe OSA.
143 citations
TL;DR: It is suggested that insomnia is a common complaint in patients being evaluated for OSA, but it is not strongly associated with sleep-disordered breathing and may instead reflect other coexisting factors.
Abstract: Obstructive sleep apnea (OSA) and insomnia are among the most common sleep diagnoses encountered in the sleep clinic population, however little is known about potential interactions or associations between the two disorders. This retrospective, cross-sectional study was designed to determine the prevalence of insomnia complaints in patients undergoing evaluation for OSA and to ascertain which clinical and polysomnographic features are associated with insomnia. Of 255 consecutive patients who underwent polysomnography for clinically suspected OSA, 54.9% reported a complaint of insomnia: 33.4% reported difficulty initiating sleep, 38.8% difficulty maintaining sleep, and 31.4% early morning awakenings. Insomnia complaints were noted more commonly in patients without significant sleep-disordered breathing [apnea hypopnea index (AHI) or =10; 51.8%); p=0.01. Clinical factors associated with insomnia included female gender, psychiatric diagnoses, chronic pain, the absence of regular alcohol use, restless leg symptoms, and reports of nocturnal kicking. Polysomnographic factors associated with insomnia included lower AHI and lower desaturation index (DI). In the subgroup of patients with significant sleep-disordered breathing (AHI> or =10, n=228), there was no association between insomnia complaints and AHI or DI. These results suggest that insomnia is a common complaint in patients being evaluated for OSA, but it is not strongly associated with sleep-disordered breathing and may instead reflect other coexisting factors.
140 citations
TL;DR: Oral appliances, especially those that advance the mandible, offer an effective treatment for OSA, and neither study group showed significant difference in mean SF36 scores.
Abstract: The purpose of this study was to investigate the effects of an oral appliance (OA), with and without mandible advance, in the treatment of obstructive sleep apnea syndrome (OSA). Twenty-four patients diagnosed with OSA agreed to participate in this study. The patients were treated for 3 months (with a removable soft elastic silicone positioner customized with thermoplastic silicone and with a 5-mm opening). Patients were selected, using a randomized design, to receive an OA model either with (12 patients) or without advance (12 patients). Before treatment, a snoring questionnaire, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), the Functional Outcomes of Sleep Questionnaire (FOSQ), the Epworth Sleepiness Scale (ESS), and polysomnography were completed. Fifteen subjects completed the protocol (13 men, two women). With respect to basal values, the mandible-advanced OA group presented a decrease in the mean apnea–hypopnea index (AHI) (33.8±4.7 versus 9.6±2.1; p<0.01), number of arousals per hour (33.8±13.9 versus 16.0±1.5; p<0.05), ESS score (14.7±5.1 versus 5.1±1.9; p<0.05), snoring score (15.4±1.9 versus 10.1±3.2; p<0.05), and total FOSQ score (78.1±22.6 versus 99.3±14.4; p<0.05). After treatment, the non-advanced group presented a decrease in the mean AHI (24.0±12.2 versus. 11.7±7.9; p<0.05). However, no significant differences were found in the number of arousals per hour, ESS score, snoring, and total FOSQ score in the non-advanced group. Neither study group showed significant difference in mean SF36 scores. Oral appliances, especially those that advance the mandible, offer an effective treatment for OSA.
134 citations
TL;DR: A self-report questionnaire was used to identify outpatients with chronic symptoms of sleep disorders and/or high pretest probability for sleep apnea as well as for restless legs syndrome, insomnia, and narcolepsy and found this population also reports chronic symptoms for otherSleep disorders and for drowsy driving.
Abstract: We used a self-report questionnaire to identify outpatients with chronic symptoms of sleep disorders and/or high pretest probability for sleep apnea as well as for restless legs syndrome (RLS), insomnia, and narcolepsy. Surveys were presented to patients waiting for an appointment in Veterans Administration (VA) Medical Center clinics in Northeast Ohio, USA. Items addressed the frequency of snoring behavior; wake time sleepiness or fatigue and history of obesity/hypertension for high risk for sleep apnea (Netzer et al. 1999), along with other symptoms, were scored as positive vs negative risk for insomnia, narcolepsy, and RLS. Of the patients offered the surveys, 886 (59.2%) provided timely responses to the questionnaire. Mean age was 62.5 years (range, 19 to 85 years); 95% were males; mean body mass index was 29.3 kg/cm(2) (range, 15.1 to 57.5 kg/cm(2)); and mean Epworth Sleepiness Scale score was 8.3 (range, 1 to 22) with 4.6% having a score >17. Of the respondents, 47.4% met high-risk criteria for sleep apnea, 41.7% for insomnia, 19% for restless leg syndrome, and 4.7% for narcolepsy. Twenty-four percent reported use of sleeping pills or bedtime alcohol. Drowsy driving >3-4 days a week or every day was reported in 5.7%. VA primary care patients have high prevalence for pretest probability for sleep apnea. This population also reports chronic symptoms for other sleep disorders and for drowsy driving.
95 citations
TL;DR: The hypothesis that OSA is linked to increased oxidative stress and decreased antioxidant defense and the serum levels of neutrophil chemokines, IL-8, and granulocyte chemotactic protein-2 suggest that systemic inflammation characterizes OSA patients.
Abstract: Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity and mortality and many other physiological and immunological disorders. An increase in hypoxia due to OSA may cause generation of reactive oxygen species (ROS). ROS are toxic to biomembranes and may lead to peroxidation of lipids. An increase in systemic biomarkers of inflammation and oxidative stress has been found in patients with OSA. The first aim of this study was to test the hypothesis that OSA is linked to increased oxidative stress (lipid peroxidation) and decreased antioxidant defense [superoxide dismutase (SOD)]. The second aim was to measure the serum levels of neutrophil chemokines [interleukin-8 (IL-8)], and granulocyte chemotactic protein-2 (GCP-2) in OSA patients. Twenty five patients with severe OSA and 17 healthy subjects were recruited. IL-8 and GCP-2 were measured in the serum by a specific enzyme immunoassay kit. Oxidative stress level was quantitated by measurement of thiobarbituric acid reactive substances. SOD enzymatic activity was measured by purely chemical system based on NAD(P)H oxidation. Mean SOD and lipid peroxidation concentrations of patients were not significantly different from those of control subjects (0.29±0.015 vs 0.31±0.01 U/ml and 4.64±0.57 vs 4.62±0.54 mmol/ml, respectively). Higher concentrations of IL-8 and GCP-2 were found in OSA patients (198.8±4.76 vs 180.83±3.38 and 383.34±46.19 vs 218±13.16 pg/ml, respectively, p<0.005). The present study does not support the hypothesis that OSA is linked to increased oxidative stress and decreased antioxidant defense. On the other hand, it suggests that systemic inflammation characterizes OSA patients.
78 citations
TL;DR: PWA obtained from a simple pulse oxymeter might be a valuable method to evaluate sleep fragmentation in sleep breathing disorders, with PWA changes greater than HR.
Abstract: The objective of the study is to evaluate changes in finger pulse wave amplitude (PWA), as measured by photoplethysmography, and heart rate (HR), related to obstructive respiratory events and associated arousals during sleep. We analyzed 1,431 respiratory events in NREM sleep from 12 patients according to (1) the type of event (apnea, hypopnea, upper airway resistance episode) and (2) the duration of the associated EEG arousal (>10, 3–10, <3 s). Obstructive respiratory events provoked a relative bradycardia and vasodilation followed by HR increase and vasoconstriction. Relative PWA changes were significantly greater than HR changes. These responses differed significantly according to EEG-arousal grades (time×arousal interaction, p<0.0001), with longer arousals producing greater responses, but not to the type of respiratory event (time×event interaction, p = ns). Obstructive respiratory events provoke HR and PWA changes, the magnitude seemingly related to the intensity of central nervous activation, with PWA changes greater than HR. PWA obtained from a simple pulse oxymeter might be a valuable method to evaluate sleep fragmentation in sleep breathing disorders.
65 citations
TL;DR: There was only modest correlation of self-reported symptoms as elicited by a questionnaire and risk for sleep disorders with common clinical assessments for HF, and collection of symptoms might be useful in establishing guidelines for routine sleep testing or as an adjunct to clinical trials.
Abstract: The purpose of this study was to survey patients with heart failure (HF) for sleep symptoms using a standardized questionnaire and correlate symptoms with conventional markers of clinical status. A self-report paper questionnaire was offered to patients presenting to a tertiary care HF clinic. Symptoms were grouped according to “risk” categories and correlated with routine clinical information. One hundred six (52.7% of 201 with all data) respondents had a high pretest probability for sleep apnea syndrome. Sixty three (31.3%) reported symptoms suggesting the presence of chronic insomnia; seven (3.5%) and eight (4%) reported symptoms of narcolepsy and restless legs syndrome, respectively. High-risk respondents for sleep apnea had a higher body mass index (p<0.001), were younger (p<0.05), and had a higher ejection fraction (p<0.05). The odds ratio (confidence interval) for paroxysmal nocturnal dyspnea (PND) to a complaint of sleepiness was 1.99 (1.1–3.6) and to a complaint of insomnia was 3.5 (1.8–6.5). In men, complaints of sleepiness in patients with PND were correlated, 4.47 (1.9–10.3), as was a correlation to high pretest probability for sleep apnea, 2.47 (1.1–5.5). There were no correlation of New York Heart Association status classification to high risk for sleep apnea, but a complaint of insomnia tended to occur with worsening functional status (p<0.05). There was only modest correlation of self-reported symptoms as elicited by a questionnaire and risk for sleep disorders with common clinical assessments for HF. Such collection of symptoms might be useful in establishing guidelines for routine sleep testing or as an adjunct to clinical trials.
54 citations
TL;DR: In patients with HF, CSR is associated with symptomatic depressive syndromes and impaired quality of life, and CRT reduced CSR with improvement of sleep quality and symptomatic depression.
Abstract: Patients with heart failure (HF) often suffer from sleep-related breathing disorders (SRBD) like Cheyne-Stokes respiration (CSR). Cardiac resynchronization therapy (CRT) improves myocardial function and exercise capacity in patients with HF and conduction disturbances. As CRT has been shown to reduce CSR in patients with HF, it is not clear whether CRT improves quality of life and symptomatic depression by improvement of apnea/hypopnea index (AHI) and sleep quality. Forty-two HF patients with conduction disturbance before CRT were screened for CSR and evaluated for sleep quality [Pittsburgh Sleep Quality Index (PSQI)], quality of life score [36-item short form (SF-36)], depression, and exercise capacity (VO2peak) and ejection fraction (EF). Eighteen patients (three females, age 61±10, body mass index 24±4 kg m−2, EF 24±4%, QRS complex duration 156±32 ms) presented CSR with an AHI of 18±8 (11 CSR, 7 mixed). Fourteen patients showed no SRBD (PSQI 10) were only present in patients with CSR. CRT results in improvement of peakVO2 and EF. There was no difference between patients with CSR and without SRBD on exercise capacity or EF under CRT, whereas CRT led to a significant decrease in AHI (18±8 to 3±2, p<0.0001), PSQI (18±4 to 6±3, p=0.0007), with reduction of depression score (12±3 to 4.8±3, p=0.004). In patients with HF, CSR is associated with symptomatic depressive syndromes and impaired quality of life. CRT reduced CSR with improvement of sleep quality and symptomatic depression.
52 citations
TL;DR: Pes parameters were found to be significant in the evaluation of the severity of the respiratory effort during the sleep-related obstructive breathing events for patients with OSAHS.
Abstract: To evaluate sleep-related obstructive breathing events in patients with obstructive sleep apnea–hypopnea syndrome (OSAHS), we developed a technique for digital recording and analysis of esophageal pressure (Pes) and elucidated the Pes parameters. Pes was recorded overnight with a microtip-type pressure transducer in 74 patients with OSAHS. Simultaneously, in all patients digital polysomnography was recorded. The mean nadir end-apneic Pes swing (Pes Nadir) ranged from −20.2 to −147.4 cmH2O, with a mean of −53.6±2.9 cmH2O. Correlation of the mean Pes Nadir indicated a linear relationship with the mean ratio of maximal Pes swing to apnea duration (r2=0.70) and the mean area of the Pes (Pes Area) (r2=0.82). Significant correlations were noted between the mean Pes Nadir and apnea–hypopnea index (AHI, ranging from 7.9 to 109.5 per hour; r2=0.66), minimum SpO2 (r2=0.60), oxygen desaturation index (ODI) of more than 3 (r2=0.65), arousal index (r2=0.54), and between the mean Pes Area and AHI (r2=0.63), minimum percutaneous arterial oxygen saturation (SpO2; r2=0.57), ODI (r2=0.69), and arousal index (r2=0.41). Pes parameters were found to be significant in the evaluation of the severity of the respiratory effort during the sleep-related obstructive breathing events for patients with OSAHS.
39 citations
TL;DR: The CPAP prediction equation modestly increases the rate of successful CPAP titrations by increasing the starting pressure of the titration, reaffirming the need for a titration study to determine the optimal prescribed level in a given patient.
Abstract: Titration of continuous positive airway pressure (CPAP) is performed to determine the CPAP setting to prescribe for an individual patient. A prediction equation has been published that could be used to improve the success rate of CPAP titrations. The goals of this study were: (1) to test the hypothesis that the use of the prediction equation would achieve a higher rate of successful CPAP titrations; (2) to validate the equation as an accurate predictor of the prescribed CPAP setting and determine the factors that influence the accuracy of the prediction equation. A total of 224 patients underwent CPAP titration prior to using the equation, with a starting pressure of 5 cm H2O. A total of 192 patients underwent CPAP titration using the equation-predicted CPAP level as the starting pressure (median starting pressure of 8 cm H2O [interquartile range 7, 10 cm H2O]). The percentage of successful studies, as defined by a 50% decrease in the apnea–hypopnea index (AHI) and a final AHI ≤10 cm H2O, increased from 50% to 68% (p<0.001), while the number of patients who were prescribed a CPAP level that had not been tested decreased from 22% to 5% (p<0.001). The equation was not accurate in predicting the prescribed level of CPAP, with only 30.8% of the patients with a prescribed pressure ≤3 cm H2O of the predicted pressure. Female gender was the only predictor of a prescribed pressure ≤3 cm H2O from the predicted pressure (odds ratio 3.45, 95% confidence intervals 1.67, 7.13, p<0.001). A CPAP prediction equation modestly increases the rate of successful CPAP titrations by increasing the starting pressure of the titration. The equation does not accurately predict the prescribed CPAP level, reaffirming the need for a titration study to determine the optimal prescribed level in a given patient.
38 citations
TL;DR: The author proposes the hypothesis that the negative pressure produced in the chest prohibits the growth of the mandible even if the patients have a capacity for growth and development, and if this negative pressure disappears because of the removal of the tonsil and/or adenoids or by an orthodontic treatment to make a patency of the airway, theMandible may grow normally, and the authors can prevent or reduce a number of OSA syndromes in the future.
Abstract: The purpose of this article is to review human craniofacial growth and development, especially the growth of the mandible, to clarify the relationship between obstructive sleep apnea (OSA) syndrome and craniofacial abnormality, and finally, to propose the hypothesis that negative pressure produced in the chest of the OSA child inhibits the growth of the mandible. Recently, the development of diagnosis and treatment of OSA syndrome has progressed rapidly; however, the prevention of OSA syndrome was merely seen. Craniofacial abnormality is reported as one of the causes of OSA syndrome. If craniofacial abnormality is determined only by genetics, it is difficult to manage the craniofacial skeleton to prevent OSA syndrome. The role of epigenetic factors on craniofacial growth and development is still controversial. However, if we stand on the functional matrix hypothesis, we can manage not only growth of the mandible but also the craniofacial skeleton as a whole. The author proposes the hypothesis that the negative pressure produced in the chest prohibits the growth of the mandible even if the patients have a capacity for growth and development; therefore, if this negative pressure disappears because of the removal of the tonsil and/or adenoids or by an orthodontic treatment to make a patency of the airway, the mandible may grow normally, and we can prevent or reduce a number of OSA syndromes in the future.
TL;DR: The therapy resulted in a decrease in the inspiratory-effort-related arousal threshold, as measured by a reduction of Pes Max, without significant changes in apnea duration and apnea-related hypoxemia.
Abstract: The maximal inspiratory effort recorded at the end of apnea has been considered as an index of arousal threshold in obstructive sleep apnea syndrome (OSAS). Previous investigations have shown that the arousal threshold is higher in patients with OSAS than in normal subjects. The aim of the present study was to investigate the effect of continuous positive airway pressure (CPAP) treatment on the inspiratory-effort-related arousal threshold in patients with OSAS. In ten male patients, 40 episodes of apnea during stage 2 non-REM (NREM) sleep were analyzed. Apnea duration (t), esophageal pressure (Pes) at the first occluded breath (Pes1), the minimum of the three initial Pes swings (Pes min), the maximum of the three final Pes swings (Pes Max), DeltaPes (Pes Max-Pes min), RPes (rate of increase of intrathoracic pressure, DeltaPes/t), n (number of occluded breaths during apnea), DeltaPes/n, n/t, and SaO(2) were determined before and after occlusion. These apneic episodes were compared to ten episodes of apnea provoked by a mask occlusion device after 1, 7, 30, and 90 days of CPAP treatment. The therapy resulted in a decrease in the inspiratory-effort-related arousal threshold, as measured by a reduction of Pes Max, without significant changes in apnea duration and apnea-related hypoxemia. Pes1 and DeltaPes/n, which are markers of respiratory drive, significantly decreased between observations. CPAP treatment decreases the inspiratory-effort-related arousal threshold and induces a decrease in ventilatory drive in response to upper airway occlusion.
TL;DR: It is suggested that regular nocturnal nCPAP treatment leads to a sustained restoration of OSAS-induced impaired endothelium-dependent nitric oxide-mediated vasodilation, suggesting an improvement of systemic endothelial dysfunction in patients studied.
Abstract: Obstructive sleep apnea syndrome (OSAS) is associated with a dysfunction of vascular endothelial cells The aim of this study was to investigate long-term improvement of endothelial dysfunction in OSAS with nasal continuous positive airway pressure (nCPAP) treatment We investigated endothelium-dependent and endothelium-independent vasodilatory function in patients with OSAS using the hand vein compliance technique Dose-response curves to endothelium-dependent vasodilator bradykinin were obtained in 16 subjects with OSAS before and after 6 months of nCPAP therapy and in 12 control subjects without OSAS Maximum dilation (Emax) to bradykinin, being impaired in all OSAS patients, was completely restored with nCPAP Mean Emax to bradykinin rose from 549+/-185 to 1082+/-287% with 1644+/-900 nights of nCPAP therapy (p<00001; Emax healthy controls, 948+/-95%) At treatment follow-up, endothelium-dependent vasodilatory capacity was not significantly different in nCPAP-treated OSAS patients vs healthy controls Mean vasodilation with endothelium independently acting nitroglycerin was not altered initially and did not change with nCPAP therapy indicating that nCPAP restored endothelial cell function and not unspecific, endothelium-independent factors These results suggest that regular nocturnal nCPAP treatment leads to a sustained restoration of OSAS-induced impaired endothelium-dependent nitric oxide-mediated vasodilation, suggesting an improvement of systemic endothelial dysfunction in patients studied
TL;DR: The magnitude of air leak that prevents auto-PAP devices from responding to respiratory events of OSA in a bench model is determined and physicians should be aware of performance limitations of auto- PAP devices in the presence of an air leak.
Abstract: Automatic positive airway pressure (auto-PAP) devices, used in the treatment of patients with obstructive sleep apnea (OSA), may not function optimally in the presence of an air leak. We set out to determine the magnitude of air leak that prevents auto-PAP devices from responding to respiratory events of OSA in a bench model. We simulated apnea, flow limitation, obstructive hypopnea, nonobstructive hypopnea, and snoring events of OSA with an artificial airway and a loudspeaker in a bench model connected to a commercially available auto-PAP device. Four auto-PAP devices were tested, but two of the "older-generation" devices (Tranquility and Virtuoso) did not respond to events of OSA that involved changes in flow contour; hence, we studied the effects of air leak and humidifier in the two "newer-generation" auto-PAP devices only (GoodKnight 418P, Autoset-T). When the air leak was progressively increased from baseline levels recommended by the manufacturer to levels seen clinically--5 to 7, 10, and 30 l/min--the GoodKnight 418P decreased pressure response by 56% (5.6+/-1.8 cm H(2)O, p=0.04). The pressure response of the Autoset-T, however, did not change from baseline during similar levels of air leak. The GoodKnight performed appropriately when the air leak was within 20 l/min, but the corresponding value for the Autoset was higher at 50 l/min. For both devices combined, air leak caused the pressure to drop between the device and the airway: 2.8+/-0.3 cm H(2)O at 30 l/min of air leak (p<0.001). Air leaks cause auto-PAP devices to underestimate the pressure required to treat events of OSA and to overestimate the pressure delivered at the upper airway. Physicians should be aware of performance limitations of auto-PAP devices in the presence of an air leak.
TL;DR: It is concluded that approximately one third of patients with sleep apnea have another identifiable sleep disorder, usually requiring treatment, which suggests that practitioners evaluating and treatingSleep apnea ought to be prepared to deal with other sleep disorders as well.
Abstract: We determined the prevalence of concomitant sleep disorders in patients with a primary diagnosis of obstructive sleep apnea (OSA). We retrospectively analyzed 643 patients, aged ≥18, with a primary diagnosis of OSA, evaluated by sleep specialists, in whom clinical and polysomnographic data were derived using standardized techniques by reviewing data from a standardized database and clinical charts. Concomitant sleep disorders were listed according to the International Classification of Sleep Disorders (American Academy of Sleep Medicine, 2000). The mean age was 48.5±13.5 years and 55% were male. Racial distributions were African–Americans 51.8% and Caucasian 47%. Indices of disordered breathing were respiratory disturbance index 32.4±30.4/h sleep and time <90% O2 saturation 44.5±81.6 min. Thirty-one percent of patients had a concomitant sleep disorder. The most common were inadequate sleep hygiene (14.5%) and periodic limb movement disorder (PLMD, 8.1%). Of patients with other sleep disorders, 66.8% had treatment initiated for these disorders. Predictors of inadequate sleep hygiene (logistic regression) were: age (each decade OR=0.678, P=0.000000), gender (for M, OR=0.536), and the presence of at least one other major system disorder (OR=2.123, P=0.0015). Predictors of PLMD were: age (each decade OR=0.794, P=0.0005), gender (for M, OR=0.433, P=0.004), and total sleep time (for each 10 min, OR=0.972, P=0.0013). We conclude that approximately one third of patients with sleep apnea have another identifiable sleep disorder, usually requiring treatment. This suggests that practitioners evaluating and treating sleep apnea ought to be prepared to deal with other sleep disorders as well.
TL;DR: It is concluded that respiratory suppression produced by the local activation of PPT neurons may not necessarily be accompanied by an REM-sleep-like cortical state in this anesthetized model.
Abstract: The pedunculopontine tegmental nucleus (PPT) has been shown to have important functions relevant to the regulation of behavioral states and various motor control systems, including breathing control Our previous work has shown that the activation of neurons within the PPT, a structure that is typically active during rapid eye movement (REM) sleep, can produce respiratory disturbances in freely moving and anesthetized rats The aim of this study was to test the hypothesis that respiratory modulation by the PPT in anesthetized rats can be evoked in the absence of other signs of an REM-sleep-like state We characterized electroencephalogram (EEG) and electromyogram (EMG) changes during respiratory disturbances induced by glutamatergic stimulation of the PPT in spontaneously breathing, adult male Sprague-Dawley rats anesthetized with a ketamine/xylazine combination or with nembutal Respiratory movements were monitored by a piezoelectric strain gauge Two-barrel glass pipettes were used to pressure inject glutamate, to probe for respiratory effective sites within the PPT, and to inject oil red dye at the end of the experiments for histological verification of the injection sites The EEGs were recorded from the sensorimotor cortex, hippocampus, and from the pons contralateral from the injection site The EMGs were recorded from the genioglossus muscle The initial response to glutamate injection into the respiratory modulating region of the PPT was always a respiratory pattern disturbance Subsequent activation of EMG and EEG often occurred in ketamine/xylazine-anesthetized rats, but REM-sleep-like patterns were not observed Respiratory pattern and EMG power changes in nembutal-anesthetized rats were similar, but EEG activation was never observed Thus, we conclude that respiratory suppression produced by the local activation of PPT neurons may not necessarily be accompanied by an REM-sleep-like cortical state in this anesthetized model
TL;DR: Ass associations between obstructive sleep apnea, intake of food rich in antioxidant nutrients, and ischemic heart disease (IHD) in military veterans are described and it is suggested that early detection of OSA may improve veterans' health and well-being and reduce associated medical costs.
Abstract: This study describes associations between obstructive sleep apnea (OSA), intake of food rich in antioxidant nutrients, and ischemic heart disease (IHD) in military veterans. Subjects were male veterans (n=211), 54 to 85 years of age, and enrolled in primary care clinics at the Southern Arizona Veterans Affairs Health Care System (SAVAHCS), Tucson, AZ. Measures included the SAVAHCS Minority Vascular Center Questionnaire, the Sleep Heart Health Study Sleep Habits Questionnaire, the Arizona Food Frequency Questionnaire, height, weight, and blood pressure. Veterans with OSA were significantly more likely to be obese, to have elevated systolic blood pressure and physician-diagnosed IHD, more likely to undergo coronary angiography, and less likely to consume foods rich in cardioprotective antioxidants compared to veterans without OSA. After adjusting for confounding variables, the association between OSA and IHD remains significant [adjusted OR=2.99, confidence interval (CI)=1.07–8.42]. These data reinforce the importance of recognizing OSA within the veterans affairs health care system and suggest that early detection of OSA may improve veterans' health and well-being and reduce associated medical costs.
TL;DR: Patients with obstructive sleep apnea syndrome and age- and BMI-matched healthy controls showed similar characteristics in terms of dysanapsis and there was no relation between the FEF25–75/FVC ratio and AHI, MinO2, and MeanO2.
Abstract: The aims of this study were to evaluate patients with obstructive sleep apnea syndrome (OSAS) with regards to dysanapsis (airway size relative to lung size) and to demonstrate the differences between the patients with and without extrathoracic airway obstruction. The study population consisted of 15 patients with OSAS and 14 age and body mass index (BMI) matched control subjects. OSAS patients and control subjects showed similar characteristics in FEV1, FEV1/FVC, FEF25–75, and FEF25–75/FVC ratios. Expiration reserve volume was significantly higher in the control group than in OSAS patients (p<0.01). Six patients exhibited extrathoracic airway obstruction while awake. Of these, three had also a sawtooth pattern in their flow–volume curves. The remaining nine patients had no extrathoracic airway obstruction and had lower apnea–hypopnea indexes (AHI) than the obstruction group (p<0.05). OSAS patients and age- and BMI-matched healthy controls had similar characteristics in terms of dysanapsis. In addition, there was no relation between the FEF25–75/FVC ratio and AHI, MinO2, and MeanO2. Extrathoracic airway obstruction may be a feature of only severe OSAS patients.
TL;DR: The increased AHI in men is secondary to an increased proportion of apneas in men compared to women and is independent of other potential determinants such as age, BMI, and NC.
Abstract: We hypothesized that the increased apnea-hypopnea index (AHI) in men compared to women was secondary to an increased proportion of apneas in men as measured by the ratio of the apnea index to the apnea-hypopnea index (AI/AHI ratio), and that the influence of gender was independent of other demographic factors such as body mass index (BMI) and neck circumference (NC). Database analysis of 501 patients (218 men and 283 women) who underwent polysomnography between August 2001 and June 2003 and who were found to have an AHI of at least five events per hour was performed. Respiratory parameters were compared between genders. To correct for differences in demographic parameters, correlations were made between AHI and the AI/AHI ratio and age, BMI, NC, and the percentage time spent in the supine position (%TST-supine) followed by a regression analysis to determine which factors independently predicted these parameters. AHI [women, 26.8 (interquartile range 13.9, 57.0) events per hour vs men, 58.9 (interquartile range 27.7, 105.7) events per hour, p<0.001] and AI/AHI ratio [women, 0.58 (0.36, 0.80) vs men, 0.80 (0.51, 0.95), p<0.001) were higher in men compared to women. The independent predictors of the AHI were male gender, BMI, NC, and the %TST-supine. Independent predictors of the AI/AHI ratio were male gender, BMI, NC, and the percentage of time spent in the supine position. The increased AHI in men is secondary to an increased proportion of apneas in men compared to women and is independent of other potential determinants such as age, BMI, and NC.
TL;DR: The signal failure and sensor loss of unattended type 2 comprehensive polysomnography (PSG) and compared that with in-lab attended PSG was compared and acceptable scorable data was available in 97% of the performed unattended PSGs.
Abstract: 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.
TL;DR: This year’s program committee chairs of the Respiratory Neurology and Sleep (RNS) assembly, Mary Morelle and Atul Malhotra, put 14 interesting poster presentation and oral presentation sessions together to cover the most actual aspects of respiratory and internal sleep medicine.
Abstract: In 1905, when Robert Koch received the Nobel Prize and the American Thoracic Society (ATS) was founded as the American Sanatorium Society, sleep medicine was on the verge but it took another 20 years to take off. Respiratory sleep medicine really started not before 30 years from now. However, 30 years is definitely enough time to reconsider what is now established as routine sleep medicine. The ATS meeting is always a good place to have a look into the future because basic research is presented here on a high level, and fierce discussions are provoked. The attendance for this year was close to 16,000 people. This year’s program committee chairs of the Respiratory Neurology and Sleep (RNS) assembly, Mary Morelle and Atul Malhotra, put 14 interesting poster presentation and oral presentation sessions together to cover the most actual aspects of respiratory and internal sleep medicine.
TL;DR: EdeSA’s first meeting focussed on the diagnosis of sleep apnea and evidence for treatment with mandibular advancement devices, as well as other sleep-related conditions, such as sleep- related bruxism, which is also recognised as an arousal disorder.
Abstract: On 5 October 2004, the very first conference of the European Dental Sleep Medicine Academy (EdeSA) was held in Prague at the Prague Conference Centre. It was organised as a satellite program of the 17th congress of the European Sleep Research Society (ESRS). EdeSA is a new association for dentists and physicians who are involved in the treatment of patients with sleep apnea, snoring or other sleep-related conditions with dental implications. The first EdeSA president, Dr. Miche De Meyer from Ghent, Belgium, who is also a founder member of this society, welcomed the ESRS president Prof. Dr. Irene Tobler and 27 attendants from ten nations to a whole-day program of lectures. President Irene Tobler held the opening ceremony and wished the new society good luck. She discussed the need for new societies with specific interests in sleep medicine, like EdeSA, representing dental sleep medicine. EdeSA’s first meeting focussed on the diagnosis of sleep apnea and evidence for treatment with mandibular advancement devices, as well as other sleep-related conditions, such as sleep-related bruxism. Prof. Dr. Dirk Pevernagie from Ghent, Belgium, who is an affiliated medical advisor of EdeSA, was the first lecturer with the task of discussing evidence-based diagnosis for sleep apnea. The audience learnt about the criteria for apneas, hypopneas and sleep arousals. Prof. Pevernagie also talked about flow limitations and the need for oesophageal pressure measurements, physical examinations and questionnaires to complement the results from the polysomnographic sleep recordings. Ass. Prof. Marie Marklund from Umeå, Sweden then talked about predictors of treatment success with mandibular advancement devices in obstructive sleep apnea and described her findings that women and men with supine-dependent sleep apneas have a high chance of treatment success with an oral device. She also presented data from a study which shows that a deep bite, the use of a soft elastomeric device and a small mandibular opening by the device reduces the orthodontic side effects from the device. EdeSAwas happy to welcome Prof. Dr. Gilles Lavigne from Montreal, Canada, who talked about obstructive sleep apnea syndrome (OSAS) and sleep-related bruxism. He emphasised that sleep-related bruxism is not the same as daytime clenching. Sleeprelated bruxism has been recently classified as a movement disorder, but the condition is also recognised as an arousal disorder. Eight percent of adults are aware of tooth grinding, which may give rise to tooth damage, headache, temporomandibular joint (TMJ) problems and bed partner complaints. The treatment for this disorder is still a subject of investiM. Marklund Umeå University, Umeå, Sweden
TL;DR: The data by Steven Scharf and his co-workers proves to me that not all those classified simply as OSA patients might be that simple as previously guessed, and the days of the good old in-clinic sleep laboratory with an array of inter-disciplinary working sleep specialists are not yet over.
Abstract: In their article, Steven Scharf and coworkers [1] present retrospective data for the prevalence of concomitant sleep disorders in 643 patients with a primary diagnosis of obstructive sleep apnea (OSA) out of 1,162 consecutive patients referred for polysomnography. The fact that 31% OSA patients had concomitant sleep disorders, and out of these 22.6% had either inadequate sleep hygiene or periodic limb movement disorder (PLMD) might not be very surprising to insiders. However, the fact that 12.5% had other sleep disorders than the two mentioned above might be of major political importance. Or to quote the authors of the paper: “The question of the role of the sleep specialist and polysomnographer in the evaluation of patients with sleep-disordered breathing is impacted by these findings”. On 21 September 2004 the Federal Board of Physicians and Public Health Care Insurances in Germany passed a federal law that polysomnography in OSA patients should be performed in an ambulant, out-patient status and reimbursed by the public health care fundings of the ambulant system for physicians in private practice (depending on the area, this means a reimbursement of 250–300 € per polysomnography for pulmonary specialists, neurologists, etc. in private practice). In-clinic sleep laboratories immediately received letters from some public health care insurances that their polysomnographies in OSA patients will not be reimbursed in the future. In the past we, the progressive fraction of sleep specialists (not to mention the English and Scotish Extremists), have pushed for the evidence-based, low-cost and simple method approach in sleep medicine. Do we have the pendulum pushed too far? Maybe! It is probably a law of nature that health insurances go for a maximum of cost reduction, no matter what. It is now our duty as sleep scientists to bring that pendulum back to the middle, where we actually, even the progressive group, wanted it to be. The data by Steven Scharf and his co-workers proves to me that not all those classified simply as OSA patients might be that simple as previously guessed. Adding heart disease patients with periodic breathing (left out intentionally in the actual study) into the equation would enlarge the number of difficult patients evenmore. The diagnosis and treatment of the concomitant sleep disorders like narcolepsy and insomnia requires definitely special sleep medicine knowledge, which can—in combination with the necessary knowledge for the respiratory part—not be delivered by just one specialist in private practice. One of the conclusions of the actual study might therefore be that the days of the good old in-clinic sleep laboratory with an array of inter-disciplinary working sleep specialists are not yet over.