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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There are several studies showing that patients with idiopathic obstructive sleep apnea (OSA) have a narrow and collapsible pharynx that may predispose them to repeated upper airway occlusions during sleep. We hypothesized that this structural abnormality may also extend to the glottic and tracheal region. Consequently, we measured pharyngeal (Aph), glottic (Agl), cervical tracheal (Atr1), midtracheal (Atr2), and distal (Atr3) tracheal areas during tidal breathing in 66 patients with OSA (16 nonobese and 50 obese) and 8 nonapneic controls. We found that Aph, Agl, and Atr1, but not Atr2 or Atr3, were significantly smaller in the OSA group than in the control group. Obese patients with OSA had the smallest upper airway area, although the nonapneic controls had the largest areas. Multiple linear regression analysis revealed that the pharyngeal area, cervical tracheal area, and body mass index were all independent determinants of the apnea-hypopnea index, accounting for 31% of the variability in apnea-hypopnea index. Aph, Agl, and Atr showed significant correlation with the body mass index. We conclude that sleep-disordered breathing is associated with diffuse upper airway narrowing and that obesity contributes to this narrowing. Furthermore, we speculate that a common pathophysiological mechanism may be responsible for this reduction in upper airway area extending from the pharynx to the proximal trachea.
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PMID:Glottic and cervical tracheal narrowing in patients with obstructive sleep apnea. 260 50

Sleep apnea syndrome is a condition characterized by recurrent interruption of breathing during sleep. Triad of symptoms for the disease are insomnia, daytime sleepiness and snoring. Recently, the patients complained of these symptoms have progressively increased. And so serious attention has been given to investigate the entity of this new clinical syndrome in medical and dental aspects. Three types of sleep apnea are classified; central, obstructive and mixed type. Most of patients identified this syndrome include obstructive or mixed types of sleep apnea. Obstructive sleep apnea has been presumed to have close relationships with obesity, micrognathia, retrognathia, tonsillary hypertrophy, tongue hypertrophy and so on. This study was designed to evaluate the characteristics of the dentofacial morphology in the obstructive, included mixed, sleep apnea syndrome (OSA) patients. The samples consisted of 25 adult male patients (average age of 48 years 2 months) with OSA as diagnosed by the division of respiratory disease, department of internal medicine, Kanazawa Medical University Hospital. One lateral radiographic cephalogram with the teeth in occlusion and the recording of somatic measurements, body weight and height, were obtained for each patient at visiting our orthodontic clinic. On the lateral cephalograms of whole samples, 10 angular and 6 linear measurements were carried out. Simultaneously, the body mass index (BMI) was assessed for each patient. Based on the cephalometric and somatometric measurements, the pathogenesis of obstructive sleep apnea was discussed in association with the obesity and dentofacial morphology. Results were summarized as follows: 1. The body mass index (kg/m2) ranged between 21.0 to 45.7, with a mean value of 31.0 for OSA patients. Of whom, 3 patients were mildly obese (25 or more of BMI) and 12 patients severely obese (exceeding 30 of BMI). 2. Compared with normal control samples, the means of cephalometric variables of whole samples showed the tendency of micrognathia, large gonial angle, protruded maxilla and large cranial base. 3. By principal component analysis, it was revealed that the components for the shape and position of the mandible were of more importance in OSA patients than controls. 4. Discriminatory analysis clarified significant differences in dentofacial morphology between 12 obese and 13 non-obese patients. 5. The dentofacial morphology in non-obese patients were characterized by retrognathia, micrognathia, large gonial angle and small maxilla. In accordance with previous reports, the patients with OSA were presented the tendency of obesity and micrognathia. Furthermore it was revealed that particularly in non-obese OSA patients the morphological abnormalities might be the major contributor to the pathogenesis of sleep apnea.
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PMID:[Dentofacial morphology of obstructive sleep apnea syndrome patients]. 264 Sep 22

Obstructive sleep apnea is frequently found in middle-aged men. Usually, these patients are obese and therefore predisposed to hypertension. This study aimed to elucidate the relationships between hypertension, obesity and obstructive sleep apnea in 48 men suffering from sleep apnea. Hypertension was found in 39 of them (= 81%), 27 patients (= 56%) were morbidly obese (Broca index above 125%), 17 patients (= 36%) were moderately obese (Broca index between 100 and 125%) and 4 patients (= 8%) showed normal weight (Broca index below 100%). Severity of sleep apnea did not correlate with obesity or hypertension. Patients with sleep apnea who were hypertensive were significantly (p less than 0.025) more obese than those with normal blood pressure. Compared with an unselected population showing a similar degree of obesity, patients with obstructive sleep apnea showed a higher prevalence of hypertension and this is independent of age. These findings establish sleep apnea as a risk factor for hypertension.
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PMID:[Obstructive sleep apnea--a risk factor for arterial hypertension]. 271 93

This report describes an unusual case of severe obstructive sleep apnea and alveolar hypoventilation leading to hypersomnolence and cor pulmonale, which were corrected by tracheostomy. Four years later, after a 22.5-kg weight gain, nocturnal apneas of similar frequency, duration, and depth of desaturation reappeared but were totally central in origin. The central apneas were eliminated with home nocturnal positive-pressure ventilation via cuffed tracheostomy tube. Each time the patient's apneas were corrected (obstructive: tracheostomy; central: mechanical ventilation), daytime alveolar hypoventilation disappeared rapidly. Yearly right heart catheterizations and radionuclide ejection fractions documented pulmonary hypertension and right heart failure, with resolution following tracheostomy and recurrence after appearance of central apneas. The changes in hemodynamic status corresponded to the patient's weight, presence of apnea, daytime alveolar hypoventilation, and treatment of nocturnal oxyhemoglobin desaturation. This case illustrates the theory of a common etiology of both central and obstructive apnea through abnormal respiratory controller gain and points to several roles obesity may play in apnea.
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PMID:Recurrence of sleep apnea syndrome following tracheostomy. A shift from obstructive to central apnea. 273 81

During breath holding, correlations have been demonstrated between the rate of fall of arterial oxyhemoglobin saturation (dSaO2/dt) and the following: thoracic gas volume at apnea onset, resting oxygen consumption, preapneic arterial oxyhemoglobin saturation (SaO2) and obesity. A key factor influencing dSaO2/dt is mixed venous oxyhemoglobin saturation (SvO2) as recently demonstrated in an animal model of obstructive apnea. The purpose of the present study was to see if dSaO2/dt was related to SvO2 during sleep in a group of subjects with severe obstructive sleep apnea (OSA) and varying levels of SvO2. Eight OSA subjects were studied during sleep with indwelling arterial and central venous catheters. Continuous SaO2 was measured by ear oximetry while continuous SvO2 was measured through the fiberoptic bundle of a Shaw Opticath catheter. Thirty percent or more of all obstructive apneas were scored for duration, preapneic SaO2, SvO2 and dSaO2/dt. Least squares regression was used to examine the relationship between dSaO2/dt and other measured variables. The dSaO2/dt showed a consistent negative correlation with preapneic SvO2 and was not related to duration. Mean dSaO2/dt during sleep correlated to some degree with the degree of gas exchange (Qva/Qt) abnormality prior to sleep. It is concluded that in humans, SvO2 plays a substantial role in determining dSaO2/dt. Potentially, the presence of gas exchange abnormalities (eg, found in intrinsic lung disease) causing hypoxemia and low SvO2 may steepen dSaO2/dt, lowering the nadir level of apneic desaturation for the same duration of apnea found in a patient with more normal gas exchange.
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PMID:The rate of fall of arterial oxyhemoglobin saturation in obstructive sleep apnea. 279 63

Guidelines for the medical therapy of obstructive sleep apnea are difficult to define precisely. While some elegant investigations have been completed, most study populations have been small. Also, the long-term effects of most forms of therapy are not known. Some patients will respond to a given form of therapy or combination of therapies while others will not. In most instances the responders cannot be recognized prior to the institution of therapy and a cycle of trial and error ensues. One of the best nonsurgical approaches appears to be weight loss, albeit unsuccessful in most cases. Almost all experts would agree, however, that in nonemergent situations weight loss should be strongly suggested. Nasal CPAP appears to be the single most promising device. Protriptyline may have a role, although in our opinion its true efficacy remains to be determined. Oxygen will probably serve more an adjunctive role in therapy, and medroxyprogesterone appears to be beneficial only in the treatment of the obesity-hypoventilation syndrome. A reasonable approach to the medical treatment of the obstructive sleep apnea patient should include, first, by history, physical examination, and appropriate laboratory testing, elimination of anatomically correctable, pharmacologic, or endocrinologic causes of OSA. If apnea length, degree of desaturation, cardiac arrhythmias, or levels of hypersomnolence are so severe as to be potentially life threatening, immediate tracheostomy is suggested. In specialized centers, nasal CPAP would be used. In less severely affected patients, medical management, as discussed above, should begin. We believe that in view of the lack of controlled trials demonstrating which form of therapy is best, the clinician must recommend therapy on the basis of local clinical experience and patient acceptance. Of fundamental importance is the need for serial reevaluation so that the impact of therapeutic failure can be minimized.
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PMID:Medical therapy of obstructive sleep apnea. 286 88

Fifty-five patients with obstructive sleep apnea syndrome (OSAS) were evaluated following inferior mandibular osteotomy with hyoid myotomy and suspension. Patients were objectively examined by polysomnography before and 6 months following the surgical procedure. Thirty-seven patients (67%) had a good response from surgery, and 18 patients (33%) were considered nonresponders. Lung disease, mandibular deficiency, and obesity were factors found to affect the success of surgical treatment.
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PMID:Inferior mandibular osteotomy and hyoid myotomy suspension for obstructive sleep apnea: a review of 55 patients. 291 51

Of 22 patients investigated for sleep disorders, habitual snoring and/or daytime hypersomnolence, 12(10 men) had obstructive sleep apnea syndrome (OSAS). 3 OSAS were mild, 5 moderate and 4 severe. The leading symptoms were daytime hypersomnolence and habitual snoring. As risk factors we found retro-micrognathia in 2 patients, macroglossia secondary to acromegaly in 1, alcohol abuse in 7 and obesity in 6. Conservative measures improved the disorder subjectively in 6 patients. One patient had a relapse 6 months after uvulopalatopharyngoplasty. 4 patients were successfully treated by nasal CPAP. Other diagnoses were idiopathic alveolar hypoventilation (2), Cheyne-Stokes breathing secondary to low cardiac output (1), monosymptomatic narcolepsy (2), sleep disturbances secondary to depression (2), chronic benzodiazepine abuse (1) and chronic bronchitis without nocturnal hypoxemia (1). History, clinical observation and oxymetry make diagnosis possible in most cases of OSAS severe enough to require treatment. Polysomnography is time-consuming and should be reserved for selected cases.
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PMID:[Sleep-apnea syndrome. Elucidation, therapy and course]. 305 35

Obstructive sleep apnea syndrome (OSAS) is a common problem in middle-aged men. It is a syndrome often associated with upper airway anatomical abnormalities, but where the sleep disorder, part of the syndrome, impairs local upper airway reflexes involved in appropriate air exchange during sleep. We now have many possible treatments. It is better to associate them in a step-by-step approach. This implies development of appropriate services able to follow OSAS patients regularly. The immediate goal is to assure normal ventilation during sleep and maintenance of normal blood gases. This is obtained by use of nasal CPAP or nasal IPPV, less mutilating than tracheostomy. Weight loss and behavioral modification programs will improve some of the associated features of obesity, alcoholic intake, and smoking often associated with and worsening the sleep-related breathing disorders. Finally, an appropriate evaluation of the upper airway abnormalities will allow surgical approaches that, as a second step, will lead to an appropriate reconstruction of the upper airway and will allow discontinuation of mechanical devices, with a subsequent return to normal life for the patient. To offer only one of these services or to limit oneself to a single therapeutic approach is a long-term disservice to OSAS patients.
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PMID:Treatment of obstructive sleep apnea syndrome. A personal view based upon evaluation of over 4000 patients. 305 71

Snoring (inspiratory noise related to narrowing of the upper airways) and obstructive sleep apnea (OSA) are two aspects of the same basic disorder: sleep-related narrowing of the upper airways. Patients with OSA have been heavy snorers for years and even decades. Lying supine induces snoring and mild OSA in heavy snorers due to hypotonia of pharyngeal dilator muscles, decreasing waking neural drive and recumbent position, which contribute to functional narrowing of the upper airways. Functional factors in obstruction during sleep include (a) respiratory instability prevalent in the male sex, (b) increased extensibility of the lax tissues surrounding the oro-pharynx and (c) deficient contraction of the pharyngeal dilator muscles during inspiration. These effects are worsened by sleep deprivation and fragmentation, alcohol intake and sedatives. Anatomical factors favoring narrowing of the upper airways in snorers and OSA patients are (a) abnormally narrow airways as well as (b) increased thickness and length of the velum palatinum in snorers and OSA patients, (c) tonsillar and adenoid hypertrophy, micro- and retrognathia, and nasal insufficiency, (d) obesity with fat infiltration of the soft tissues and in particular of the oropharynx, (e) relatively open mandibular angle, hypertrophy and thickness of the tongue, and lowered hyoid bone (as shown by MRI imaging). It is possible that many anatomical abnormalities may be the consequence of snoring and obstructive apnea. During NREM sleep the ineffective inspiratory efforts progressively increase with worsening hypoxia and hypercapnia. The upper airways become patent again when arousal induces phasic activation of the dilator pharyngeal muscles.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pathogenic aspects of snoring and obstructive apnea syndrome. 318 70


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