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PubMed2006

Gender differences in global cardiovascular risk factors of obstructive sleep apnea patients.

The morbidity and mortality of obstructive sleep apnea (OSA) are related principally to its cardiovascular complications. Metabolic syndrome (MBS) is recognized as raising the risk of cardiovascular disease. In this study, we analysied the diagnostic value of MBS to predict the diagnosis of severe OSA. Eight-seven subjects (54 males and 33 females) without any cardiac or pulmonary disease referred for evaluation of OSA, had overnight polysomnography. MBS were diagnosed according to NCEP criteria. According to apnea-hypopnea index (AHI), subjects were divided into two groups: severe OSA (AHI>or=30, 26 males, 15 females) and non-severe OSA (AHI<30, 28 males, 18 females). Ages were similar in both OSA groups for both genders. In the severe OSA group, number of patients with MBS was especially higher (in females n=13, 86.6%; in males n=19, 73%) than non-severe OSA (in females 6, 33%, in males 9, 32%). The mean values of the five diagnostic criteria of MBS were significantly higher in severe OSA than non-severe groups in both genders. Analysis of diagnostic value (criteria>or=3) of MBS for predicting the diagnosis of severe OSA in males and females revealed the sensitivity 73% and 86.6%, the specificity 67.8% and 94.4%, positive predictive value 67.9% and 86.7%, negative predictive value 73% and 85.7% respectively. Especially in female patients referred to the sleep clinics, evaluation of MBS criteria may play an important role in predicting severe OSA with high sensitivity and negative predictivity. Furthermore, the presence of MBS in OSA patients might increase cardiovascular complications.

Female↗

PubMed1998

The obstructive sleep apnoea syndrome--experience of a referral centre.

OBJECTIVE: The aims of this study were: (i) to document the presence and severity of obstructive sleep apnoea (OSA) in patients who complained of heavy snoring and other symptoms suggestive of the OSA syndrome; (ii) to examine the correlation between the clinical and polygraphic findings, and (iii) to document the efficacy and compliance of nasal continuous positive airway pressure (CPAP) among these Asian snorers with OSA. METHODS: We analysed our clinical and nocturnal polysomnographic data between January 1986 and December 1995 for physician-referred patients who had complained of snoring and other symptoms suggestive of OSA. RESULTS: A total of 277 diagnostic studies were performed of which 145 (52%) were positive to OSA. For studies performed in the last 2 years (n = 125), 72 of the 125 were positive for OSA. Anthropometric data was not discriminative between the OSA positive snorers and the OSA negative snorers. We found that hypertension and choking were the most significantly related to OSA, conferring a 7 and 4 times relative risk respectively. Nasal CPAP eliminated snoring, apnoeas and oxygen desaturations completely in almost all cases and there were only minor mask-related side effects. CONCLUSION: OSA may not be uncommon among Asian snorers. Of the major traits for OSA risk among our local population, a history of hypertension and reports of nocturnal choking were the most significantly related. We have also shown that nasal CPAP is safe and effective among our local snorers and should be considered a first-line treatment for OSA.

Adult↗

PubMed2006

Perioperative care of patients with obstructive sleep apnea - a survey of Canadian anesthesiologists.

PURPOSE: At present, there are no guidelines and insufficient evidence to guide the decision-making of anesthesiologists in the perioperative care of patients with obstructive sleep apnea (OSA). The purpose of this study was to examine the current perioperative care provided, and to obtain opinions from anesthesiologists regarding evidence/consensus based guidelines to assist them in providing care to patients with OSA. METHODS: Canadian anesthesiologists were sent a postal questionnaire examining their opinions and perioperative care of patients with OSA. Respondents were asked to indicate the postoperative monitoring they would most likely select for two clinical scenarios, representing administration of a general and regional anesthetic, which was altered to reflect: treatment of OSA; use of postoperative opioids; presence of morbid obesity; and increased severity of OSA. RESULTS: The survey had a response rate of 70% (746/1,063). Sixty-seven percent of respondents provided perioperative care to one to five patients with OSA per month, and 72% reported not having departmental policies for care of OSA patients. Ninety-two percent reported asking patients about OSA preoperatively. There was >or= 75% respondent agreement in two of the five alterations of the general anesthesia case scenario and in none of the alterations of the regional anesthesia case scenario. Eighty-two percent reported that guidelines would assist them in caring for patients with OSA. CONCLUSION: This study demonstrates a variation amongst anesthesiologists in their postoperative monitoring of patients with OSA. The majority surveyed do not have departmental policies, and believed that guidelines would assist them in providing care to patients with OSA.

Anesthesiology↗

PubMed2000

Morphometric analysis of the uvula in patients with sleep-related breathing disorders.

The upper-airway mucosa in obstructive sleep apnea (OSA) patients and snorers is often described as edematous and hyperplastic. The morphologic aspects of the pharyngeal mucosa, and in particular the mucosa of the uvula and soft palate, in OSA patients are, however, not well described. The aim of the present retrospective study therefore was to perform histologic examination of the pharyngeal mucosa obtained from patients with various forms of sleep-related breathing disorders, including primary snoring. A midsagittal section of uvulas obtained by uvulopalatopharyngoplasty (UPPP) was investigated in 34 OSA patients and 9 non-apneic snorers. Control tissues were taken by autopsy in 19 patients not known to have OSA or snoring. A morphometric point counting technique was used to determine the tissue composition. The data showed that OSA patients and non-apneic snorers had a significantly greater percentage of intercellular space than controls (65.7% vs 54.0%; P = 0.006). Control uvulas contained more muscle than OSA and snorers (14.0% vs 7.8%; P = 0.006). Moreover, the covering epithelium was significantly thicker in OSA and snorers than in controls (variance ratio = 7.64; P = 0.008). When taking body mass index (BMI) into account, no correlation was found between fat deposition and BMI. Findings showed that an increased clinical severity of OSA did not affect the tissue composition. Indeed, uvula morphology was similar in OSA patients with respect to non-apneic snorers. Since the increased amount of intercellular space is the expression of edema, we hypothesize that these mucosal changes together with hyperplasia of the covering epithelium are secondary effects to snoring. They presumably play a minor role in the etiopathogenesis of OSA, but may increase the severity of OSA by further narrowing the pharyngeal lumen.

Female↗

PubMed2004

Knowledge, opinions, and clinical experience of general practice dentists toward obstructive sleep apnea and oral appliances.

Undiagnosed obstructive sleep apnea (OSA) can contribute to hypertension, cardiovascular disease, stroke, and detract from overall quality of life. Dentists can play an important role in detecting, making recommendations for, and treating OSA with oral appliances (OAs). A survey of 18 questions of knowledge and opinion of, educational background for, and clinical experience with OSA and OAs was mailed to 500 general practice dentists in Indiana, United States. Two hundred survey returns produced 192 valid responses. Responders reported strong positive opinions toward OSA and OAs. However, 58% of dentists could not identify common signs and symptoms of OSA, and 55% of dentists did not know the mechanism for mandibular advance devices. Only 39% of dentists could identify snoring, mild OSA, and intolerance to continuous positive airway pressure as possible indications for OA treatment. Respondents reported a general lack of education about both OSA and OAs. Only 31 (16%) were taught about this issue in dental school; 77 (40%) knew little or nothing about OA treatment for OSA patients; 57 (30%) learned from postgraduate training. Cooperation and referrals between dentists and physicians were rated as "poor." Of the responders, 54% never consulted with physicians for a suspected OSA patient in their practice; 75% of dentists reported they have never been referred patients by physicians; and 80% of dentists never or less than five times prescribed OAs to OSA patients. Results suggest a need for increased education and training regarding OSA and OAs in dental school, as well as increased cooperation between dentists and physicians for better patient care.

Attitude of Health Personnel↗

PubMed2005

Quality of life after adenotonsillectomy for SDB in children.

OBJECTIVE: To evaluate the relationship between quality of life and the relative severity of sleep-disordered breathing (SDB) and to compare changes in quality of life after adenotonsillectomy in children with similar demographics but with either obstructive sleep apnea syndrome (OSAS) or with milder forms of SDB. STUDY DESIGN AND SETTING: All study participants underwent polysomnography to document the severity of SDB. The effectiveness of adenotonsillectomy for the relief of SDB was evaluated by using the OSA-18 quality of life survey (OSA-18). Preoperative and postoperative OSA-18 scores for each group of children (OSAS and mild SDB) were compared by using a repeated measures ANOVA. Changes between the 2 groups were compared by using an analysis of covariance with the preoperative score as a covariate. RESULTS: The study population included 61 children, 43 with OSAS and 18 with mild SDB. The demographics in the 2 groups were similar. The mean apnea-hypopnea index for children with OSAS was 21 (range, 5-46), and for children with mild SDB, it was 3 (range 0-4.9). The total OSA-18 score and the scores for all domains showed significant improvement after surgery for both groups of children (P < .001). A comparison of mean difference in total and domain scores for the 2 groups of children was not significant. CONCLUSIONS AND SIGNIFICANCE: Preoperative values for the OSA-18 total and domain scores are high in children with either OSAS or mild SDB. Both groups of children show a dramatic improvement in quality of life after adenotonsillectomy and the degree of improvement is similar. Fortunately, surgical therapy with adenotonsillectomy is associated with marked improvement in quality of life for children with either OSAS or mild SDB.

Adenoidectomy↗

PubMed2005

A pilot study to assess the possible methods of determining the burden of obstructive sleep apnoea syndrome in primary care.

INTRODUCTION: A significant minority of otherwise healthy adults may suffer from disordered breathing during sleep. The commonest problem, known as Obstructive Sleep Apnoea Syndrome (OSAS), results in poor quality sleep, daytime hypersomnolence and excess risk of road traffic crashes. It is also associated with occupational injuries. OSAS can be successfully treated, reducing costs of hospitalisation. There is a gap in the literature regarding the burden of patients with OSAS in primary care, particularly because there is no agreed method for screening. OBJECTIVES: This pilot study was designed to determine the feasibility of screening for OSAS in a UK inner-city multi-ethnic primary care population, to investigate ways in which it might be detected, and to gain an awareness of the potential size of the burden of OSAS METHODS: We tested two methods of screening: firstly, postal questionnaires to a random sample of 240 patients from a subset of the population at highest risk of OSAS (men aged 35-65 years); and secondly, the same questionnaire plus two screening tools for detecting hypersomnolence, given to patients attending the practice for pre-registration health checks. RESULTS: Despite reminders, only 40% of postal questionnaires were returned and there were only 67 (28%) usable responses. The prevalence of snoring was 55%. Almost half of those patients who responded (46%) had a Body Mass Index (BMI) associated with a high risk of OSAS. This was not a positive responder bias because there were no significant differences in BMI between responders and non-responders. 12% had a collar size of greater than 17.5, whilst 34% reported daytime sleepiness, and 24% reported witnessed apnoea. Screening during pre-registration health checks proved both feasible and productive with 38 patients of differing linguistic abilities completing the assessment. CONCLUSION: Screening for OSAS in primary care by means of a postal questionnaire produced a low response. Whilst there was no evidence of a responder bias in terms of BMI, the numbers reporting large collar size, daytime sleepiness and witnessed apnoea suggest that a sizeable proportion of the population is at risk of OSAS. Questionnaires used in this study provide a means of identifying patients with symptoms suggestive of OSAS, although the sensitivity, specificity and positive predictive value of a self-administered instrument needs to be confirmed by a larger study incorporating ventilatory monitoring during sleep. The addition of screening to pre-registration health checks is feasible, but it would take a long time to screen all those at risk for OSAS by this route.

Journal Article↗

PubMed2004

Association of autonomic dysfunction and mild obstructive sleep apnea.

BACKGROUND: Autonomic dysfunction (AD) has been independently associated with obstructive sleep apnea (OSA). Autonomic abnormalities are generally considered to be secondary to OSA. Autonomic dysfunction may also contribute to OSA. If AD contributes to OSA, we postulated that abnormalities may be present in mild OSA where the confounding causal effects of hypoxemia and sleep disruption are reduced. OBJECTIVE: We evaluated autonomic function tests and sleep studies in a cohort of subjects with no known diagnosis of OSA. METHODS: We prospectively enrolled a cohort without diagnosed OSA who were part of an ongoing study of vasomotor rhinitis (VMR) for testing. A battery of autonomic nervous system tests (sudomotor and cardiovagal), nonattended polysomnography, and three-site esophageal/pharyngeal pH monitoring were performed. RESULTS: Twenty of 22 patients completed the test battery and 12 (60%) met criteria for OSA (Apnea/Hypopnea Index "AHI" >5 events/hour). AHI correlated to mean tilt table blood pressure decrease (R = 0.58, P = 0.007) and the Valsalva-mediated phase 2 mean blood pressure decrease (R = 0.52, P = 0.017). OSA severity was related to sympathetic but not parasympathetic abnormalities. No differences in blood pressure responses were related to age, oxygen desaturation nadir, gastroesophageal reflux, VMR, or sleepiness. CONCLUSION: Autonomic abnormalities suggestive of decreased adrenergic tone are associated with mild OSA. These abnormalities may potentially be secondary but may also precede development of OSA.

Autonomic Nervous System↗

PubMed2000

Hypercapnia in obstructive sleep apnoea syndrome.

BACKGROUND: The reports on the prevalence of hypercapnia in Obstructive Sleep Apnoea Syndrome (OSAS) are conflicting. We studied the prevalence of hypercapnia in a population of OSAS patients referred to a Department of Respiratory Medicine and the mechanism of the respiratory failure in OSAS associated with Obesity Hypoventilation Syndrome (OHS) or with Chronic Obstructive Pulmonary Disease (COPD) (Overlap syndrome). METHODS: We studied 219 consecutive OSAS patients during a period of 3 years. We recorded age and anthropomorphic data and performed polysomnography and pulmonary function tests. In relation to the value of PaCO(2), the patients were divided in hypercapnic (PaCO(2)>45 mmHg) patients and normocapnic patients. They were also divided into three groups in relation to the presence of "simple" or "pure" OSAS, to the presence of OSAS associated with COPD, to the presence of OSAS associated with OHS. RESULTS: Seventeen per cent of the patients were hypercapnic. They were significantly heavier, had more severe lung function test abnormalities and more severe nocturnal oxyhemoglobin desaturations than the normocapnic ones, while Forced Expiratory Volume in one second as a percentage of Forced Vital Capacity (FEV1/FVC %) and Apnoea/Hypopnoea Index (AHI) were similar. OHS patients (13%) were significantly younger and heavier, had lower PaO(2) and higher PaCO(2) than "simple" OSAS patients (77%) and Overlap patients (10%) and had more severe restrictive defect. There was no difference in terms of AHI among the three groups, but nocturnal oxyhemoglobin desaturations were more severe in OHS group. In OHS group hypercapnia was correlated to FVC% of predicted and FEV1% of predicted and to the mean nocturnal oxyhemoglobin saturation; in Overlap patients PaCO(2) was correlated to Forced Expiratory Flow rate at low Vital Capacity. CONCLUSION: Seventeen per cent of OSAS patients referred to a Department of Respiratory Medicine were hypercapnic. Hypercapnia in OHS patients correlates to the restrictive ventilatory defect whereas in Overlap patients it seems to correlate to peripheral airways obstruction. The distinction between patients with "simple" or "pure" OSAS and patients affected by OSAS associated with OHS or COPD could be important not only for clinical and prognostic implications, but also for the consequences in terms of ventilatory treatment.

Adolescent↗

PubMed1996

Cephalometric comparisons of craniofacial and upper airway structure by skeletal subtype and gender in patients with obstructive sleep apnea.

To investigate whether patients with obstructive sleep apnea (OSA) have abnormalities in their craniofacial and upper airway (UA) structures compared with normal subjects, cephalometric comparisons were systematically performed in both the upright and the supine positions in subjects with and without OSA, who were then grouped according to their craniofacial skeletal type and gender. A total of 347 patients with OSA and 101 control subjects were divided into male and female groups and then classified into Class I (CI), Class II, Division 1 (CII/1), Class II, Division 2 (CII/2), and Class III (CIII) skeletal subtypes. In the upright position, the most atypical craniofacial and UA structure was shown in male patients with CI OSA. In patients with OSA, the degree of UA abnormalities was less in the supine position regardless of skeletal subtype. In the supine position, the most atypical craniofacial and UA structure was also shown in male patients with CI OSA; there were no significant differences between male patients with CII/2 OSA and control subjects or between female patients with CI OSA and control subjects. With a change in body position from upright to supine, distinctive changes in the UA structure in both patients with OSA and control subjects occurred, according to skeletal subtype and gender. We conclude that there are a series of characteristics of craniofacial and UA structure that differ between patients with OSA and control subjects matched for skeletal subtype and gender. These differences may predispose to UA obstruction during sleep in patients with OSA.

Adult↗

PubMed2003

Physical properties of octenyl succinic anhydride modified rice, wheat, and potato starches.

The physical properties of octenyl succinic anhydride (OSA) starches prepared from rice, wheat, and potato starches were studied. Rice and wheat OSA starches had significantly higher peak viscosity (PV), hot paste viscosity (HPV), and cool paste viscosity (CPV), but potato OSA starch had only significantly higher CPV, relative to the native starch. The gel hardness was higher with lower degree of substitution (DS) but lower with higher DS OSA compared to native starch. The swelling volumes (SV) of rice and wheat OSA starches were significantly higher compared to native starch, but the SV of potato OSA starch was slightly lower at high DS. The gelatinization temperature (GT) of rice OSA starches was sharply lower at low DS; for wheat OSA starch it was slightly lower even at high DS, but potato OSA starches had higher GT than the native starch. The enthalpy of all the OSA starches decreased gradually with increased DS. This study showed that the magnitude of changes in physical properties of OSA-modified starches depends not only on their DS but also on the botanical origin of the native starches.

Chemical Phenomena↗

PubMed2003

Craniofacial morphology and obstructive sleep apnoea: a cephalometric analysis.

The craniofacial morphology of 31 male patients diagnosed with obstructive sleep apnoea syndrome (OSAS) and 37 healthy male subjects were compared using cephalometric evaluation of lateral skull radiographs. The aim was to evaluate which cephalometric variables related to craniofacial morphology discriminate between OSAS patients and non-OSAS subjects. Sixteen cephalometric measurements were determined to study the craniofacial morphology. Differences in cephalometric variables between the two groups were analysed with unpaired Student t-tests (significance level 0.05). A multiple regression analysis was used to evaluate the joint predictive value of selected variables. With regard to five variables, significant differences were observed between OSAS patients and non-OSAS subjects (P < 0.05). Data indicated a relatively anterior position of the maxilla, an increase of the mid-facial height and a more inferiorly located hyoid bone in the OSAS patient group. The multiple regression analysis yielded a model discriminating between OSAS patients and non-OSAS subjects, which included two hyoid bone variables and one related with the intermaxillary relationship. A causal relationship between cephalometric variables of craniofacial morphology and OSAS is not sufficiently supported by our data. Presumably, hyoid bone position is of predictive value in the cephalometric discrimination between OSAS patients and non-OSAS subjects.

Adult↗

PubMed2000

Sleep architectures of obstructive sleep apnea syndrome in the young child.

The sleep architectures of obstructive sleep apnea syndrome (OSAS) in the young child (child-OSAS, n = 17; mean age: 5.9+/-2.7 years; male:female 14:3) were compared with that of OSAS in the adult (n = 19; mean age: 44.7+/-10.7 years; male:female 18:1) and that of primary snoring in the child (n = 5; mean age: 7.0+/-2.4 years; male:female 5:0). Child-OSAS and OSAS in the adult had the same severity in oxygen desaturation. Child-OSAS showed lower Apnea-Hypopnea Index compared with OSAS in the adult. Sleep continuity in child-OSAS was not impaired compared with OSAS in the adult. Sleep fragmentation in child-OSAS was not so remarkable. The quantity of slow wave sleep in child-OSAS was similar to that of primary snoring in the child. Both profiles of sleep architectures showed nearly the same pattern.

Cerebral Cortex↗

PubMed2003

Obstructive sleep apnea in a clinical series of adult epilepsy patients: frequency and features of the comorbidity.

PURPOSE: The aim of this study was to evaluate the rate and features of obstructive sleep apnea (OSA) in adult epilepsy patients. METHODS: Two hundred eighty-three adult epilepsy patients (137 men; mean age, 33 years; range, 18-70 years) were prospectively screened for OSA by means of a structured interview. Those in whom OSA was clinically suspected were monitored for a full night by using a portable device (Polymesam), and OSA was diagnosed when they had an Apnea/Hypopnea Index greater than five. RESULTS: Coexistence of OSA with epilepsy was found in 10.2% (15.4% of the male and 5.4% of the female) epilepsy patients investigated. The OSA was mild in 66.6%, moderate in 22.2%, and severe in 11.1% of the cases. The "epilepsy + OSA" patients were older, heavier, more frequently male, and sleepier (p < 0.05) than those with "epilepsy only." Furthermore, they experienced their first seizure at an older age (p < 0.05). CONCLUSIONS: Systematic investigation reveals that OSA is frequent in epilepsy patients. The major risk factors for OSA in our epilepsy patients were the same as those typically found in the general population. Of the epilepsy-related factors, older age at onset of seizures appears to be significantly related to comorbidity with OSA (p < 0.05). The presence in epilepsy patients of these features should alert the clinician to the possibility of an underlying OSA.

Adolescent↗

PubMed2004

Reducing motor-vehicle collisions, costs, and fatalities by treating obstructive sleep apnea syndrome.

STUDY OBJECTIVES: Drivers suffering from obstructive sleep apnea syndrome (OSAS) have an increased risk for being involved in motor-vehicle collisions. This study estimates, for the first time, the annual OSAS-related collisions, costs, and fatalities in the United States and performs a cost-benefit analysis of treating drivers suffering from OSAS with continuous positive airway pressure (CPAP). DESIGN: The MEDLINE-PubMed database (1980 to 2003) was searched for information on OSAS. A meta-analysis was performed of studies investigating the relationship between collisions and OSAS. Data from the National Safety Council were used to estimate OSAS-related collisions, costs, and fatalities and their reduction with treatment. Next, the annual cost of treating OSAS with CPAP was calculated. Finally, multiple 1-way sensitivity analyses were performed. SETTING: N/A. PATIENTS OR PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: More than 800,000 drivers were involved in OSAS-related motor-vehicle collisions in the year 2000. These collisions cost 15.9 billion dollars and 1,400 lives in the year 2000. In the United States, treating all drivers suffering from OSAS with CPAP would cost 3.18 billion dollars, save 11.1 billion dollars in collision costs, and save 980 lives annually. CONCLUSION: Annually, a small but significant portion of motor-vehicle collisions, costs, and deaths are related to OSAS. With CPAP treatment, most of these collisions, costs, and deaths can be prevented. Treatment of OSAS benefits both the patient and the public.

Accidents, Traffic↗

PubMed1998

Identification of obstructive sleep apnea in patients who snore.

As the field of sleep medicine has evolved, the clinical implications of obstructive sleep apnea (OSA) in snoring patients have become well accepted. Recent advances in surgical therapy for snoring allow otolaryngologists to offer simple outpatient treatment to patients with this problem. However, because the incidence of OSA in snorers seeking medical attention is unknown, the appropriate pretreatment evaluation of these patients is a subject of continued debate. Ninety-four snoring patients were recruited for a study to determine the incidence of OSA in this highly selected population. Subjects answered an extensive sleep questionnaire to determine factors that might suggest a diagnosis of OSA. Level III ambulatory sleep studies were performed on each participant. The incidence of OSA in this group was 72% (42% severe and 30% mild to moderate). Twenty of the subjects with OSA also underwent formal level I sleep studies, and the diagnosis of OSA was confirmed in each instance. Although there was a relationship between body mass index and OSA and certain questions correlated with OSA, the sensitivity and specificity of these data alone or in combination were too low to recommend their use in lieu of a formal sleep study. Given the remarkably high incidence of OSA in this group, which may reflect that seen by otolaryngologists who treat snoring, a sleep study should be performed to diagnose OSA and institute therapy for this condition. Level III ambulatory monitoring devices may be the most cost-effective alternative for evaluating this high-risk population.

Adult↗

PubMedDate not supplied

Prevalence of left ventricular hypertrophy in persons with and without obstructive sleep apnea.

We investigated the prevalence of left ventricular hypertrophy (LVH) in persons with and without obstructive sleep apnea (OSA). Fifty-three persons had a nocturnal polysomnogram to diagnose OSA and 2-dimensional echocardiograms to measure left ventricular mass. OSA was considered mild if the respiratory disturbance index (RDI) was 5 to 15, moderate if the RDI was 15 to 30, and severe if the RDI was >30. LVH was diagnosed if the left ventricular mass index was >110 g/m in women and >134 g/m in men. LVH was present in 21 of 27 persons (78%) with moderate or severe OSA, in 6 of 13 persons (46%) with mild OSA, and in 3 of 13 persons (23%) with no OSA (P < 0.001 comparing moderate or severe OSA with no OSA and P < 0.05 comparing moderate or severe OSA with mild OSA). OSA was a significant independent predictor of LVH after controlling the confounding effects of hypertension with an odds ratio of 3.579 (95% confidence interval, 1.589-8.058).

Adult↗

PubMed2005

The effect of sleep onset on upper airway muscle activity in patients with sleep apnoea versus controls.

Pharyngeal dilator muscles are important in the pathophysiology of obstructive sleep apnoea syndrome (OSA). We have previously shown that during wakefulness, the activity of both the genioglossus (GGEMG) and tensor palatini (TPEMG) is greater in patients with OSA compared with controls. Further, EMG activity decreases at sleep onset, and the decrement is greater in apnoea patients than in healthy controls. In addition, it is known that the prevalence of OSA is greater in middle-aged compared with younger men. Thus, we had two goals in this study. First we compared upper airway muscle activity between young and middle-aged healthy men compared with men with OSA. We also explored the mechanisms responsible for the decrement in muscle activity at sleep onset in these groups. We investigated muscle activity, ventilation , and upper airway resistance (UAR) during wakefulness and sleep onset (transition from alpha to EEG activity) in all three groups. Measurements were obtained during basal breathing (BB) and nasal continuous positive airway pressure (CPAP) was applied to reduce negative pressure-mediated muscle activation). We found that during wakefulness there was a gradation of GGEMG and UAR (younger < older < OSA) and that muscle activity was reduced by the application of nasal CPAP (to a greater degree in the OSA patients). Although CPAP eliminated differences in UAR during wakefulness and sleep, GGEMG remained greater in the OSA patients. During sleep onset, a greater initial fall in GGEMG was seen in the OSA patients followed by subsequent muscle recruitment in the third to fifth breaths following the alpha to transition. On the CPAP night, and GGEMG still fell further in the OSA patients compared with control subjects. CPAP prevented the rise in UAR at sleep onset along with the associated recruitment in GGEMG. Differences in TPEMG among the groups were not significant. These data suggest that the middle-aged men had upper airway function midway between that of young normal men and the abnormal airway of those with OSA. Furthermore it suggests that the initial sleep onset reduction in upper airway muscle activity is due to loss of a 'wakefulness' stimulus, rather than to loss of responsiveness to negative pressure, and that this wakefulness stimulus may be greater in the OSA patient than in healthy controls.

Adolescent↗