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

Multiple methods have been used to study the structure and physiological behavior of the upper airway (UA) in patients with obstructive sleep apnea (OSA). Valuable information may be obtained from the physiologic measurement of pressure and resistance along the UA, as well as from imaging techniques that include: direct or fiberoptic visualization, cephalometric roentgenograms, fluoroscopy, acoustic reflection, computerized tomography, and magnetic resonance imaging. This review summarizes the information that each of these methods has contributed to our understanding of the UA. The results obtained with these different methodologies have generally been complementary with structural narrowing being identified in the majority of patients with OSA. This narrowing is usually focal and located in the velopharyngeal or retropalatal segment of the UA. This is also the predominant site of initial UA collapse. Although obesity with enlargement of soft tissue structures is considered the predominant mechanism leading to UA narrowing, abnormal craniofacial development on a genetic or developmental basis plays an important contributory role.
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PMID:Evaluation of the upper airway in patients with obstructive sleep apnea. 194 2

The obstructive sleep apnea (OSA) syndrome has been considered to be a cause of both transient blood pressure elevations during sleep and sustained hypertension during the awake state. The purpose of this review was to examine critically the existing literature regarding (1) the blood pressure alterations associated with OSA, (2) causal mechanisms relating specific blood pressure alterations to OSA, and (3) potential consequences of the systemic circulatory abnormalities associated with OSA. Particular attention was directed at studies that assessed the prevalence of OSA in patients with hypertension and that examined the effects on blood pressure of treatment of OSA. We conclude that patients with OSA have abnormal sleep blood pressure patterns, manifested most frequently by apnea-associated blood pressure elevations. Confounding factors such as obesity and antihypertensive drug therapy, and conflicting evidence regarding changes in daytime blood pressure after therapy for OSA, make it premature to conclude that OSA and daytime hypertension are directly associated. Circumstantial evidence suggests that the blood pressure alterations that occur during sleep could contribute to the high cardiovascular morbidity in patients with OSA. Further research into the relationship between OSA and hypertension should improve the future care of patients with these conditions and enhance our understanding of cardiopulmonary pathophysiology.
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PMID:Causes and consequences of blood pressure alterations in obstructive sleep apnea. 200 Nov 27

We examined the prevalence of daytime hypertension in a modern sample of patients with obstructive sleep apnea (OSA) and assessed the relative risk factors contributing to the development of hypertension in this disorder. Daytime hypertension was present in 92 (45 percent) of 206 male and female patients with OSA. Stepwise logistic regression revealed that only age and body mass index (BMI) were predictors of hypertension in this population. A subsample of 152 male patients with OSA was then compared to 904 men identified from a geographically and ethnically similar general population. When one controlled for age and BMI, the prevalence of hypertension in the two groups was the same except for those aged 25 to 44 years who were markedly obese (BMI greater than 31 kg/m2). In this group, 47 percent of the patients with OSA were hypertensive vs 26 percent of control subjects (p less than 0.05). Our data suggest that the high prevalence of hypertension in OSA is primarily related to age and the excess obesity seen in these patients. In morbidly obese young patients with OSA, factors directly related to OSA may also be contributing to the development of hypertension. With increasing age, other competitive risks may obscure any independent effect that OSA may exert.
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PMID:Daytime hypertension in obstructive sleep apnea. Prevalence and contributing risk factors. 200 87

One thousand and one men, aged 35-65 years, were identified from the age-sex register of one group general practice. Over four years 900 men were visited at home and asked questions about symptoms potentially related to sleep apnoea and snoring. Height, weight, neck circumference, resting arterial oxygen saturation (SaO2), and spirometric values were also determined. All night oximetry was then performed at home and the tracing analysed for the number of dips in SaO2 of more than 4%. Subjects with more than five dips of 4% SaO2 or more per hour were invited for sleep laboratory polysomnography. Seventeen per cent of the men admitted to snoring "often." Multiple linear regression techniques identified and ranked neck circumference (r2 = 7.2%), cigarette consumption (r2 = 3.4%), and nasal stuffiness (r2 = 2%) as the only significant independent predictors of snoring. Together these account for at least a sixfold variation in the likelihood of being an "often" snorer. Forty six subjects (5%) had greater than 4% SaO2 dip rates of over five an hour and 31 of these had full sleep studies. Three subjects had clinically obvious and severe symptomatic obstructive sleep apnoea, giving a prevalence of three per 1001 men (0.3%; 95% confidence interval 0.07-0.9%). Eighteen men had obstructive sleep apnoea only when supine and in 10 the cause of the SaO2 dipping on the original home tracing was not elucidated. The greater than 4% SaO2 dip rates correlated with the history of snoring. Multiple linear regression techniques identified and ranked neck circumference (r2 = 7.9%), alcohol consumption (r2 = 3.7%), age (r2 = 1%) and obesity (r2 = 1%) as the only significant independent predictors of the rate of overnight hypoxic dipping. This study shows that snoring in this randomly selected population correlates best with neck size, smoking, and nasal stuffiness. Obstructive sleep apnoea, defined by nocturnal hypoxaemia, correlates best with neck size and alcohol, and less so with age and general obesity.
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PMID:Predictors and prevalence of obstructive sleep apnoea and snoring in 1001 middle aged men. 201 7

Obstructive sleep apnoea is a common disorder in western societies and has a strong association with obesity and alcohol use. The condition has not previously been recorded in Papua New Guinea. The clinical details of 2 patients from Papua New Guinea with obstructive sleep apnoea are described, and the principles of treatment of this condition are outlined. Sleep apnoea is likely to become an increasing problem in Papua New Guinea.
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PMID:Obstructive sleep apnoea: a new disease for Papua New Guinea? 208 Jun 74

The OSA syndrome, described over 100 years ago, was rediscovered in 1966. It is a common disorder, especially among fat, middle-aged men. Stentorian snoring and diurnal somnolence are the cardinal manifestations and should always lead to an examination during sleep. That examination (polysomnography) can demonstrate the pathognomonic events--repetitive apneas occurring in sleep--which signal the failure of the sleeping brain to maintain the patency of the supraglottic airway. All evidence points to the problem being an abnormal pharyngeal airway, one which has a shape or size or compliance that allows inspiratory collapse as the normal loss of pharyngeal dilator muscle tone occurs with sleep. The apneas are asphyxic events terminated by arousals which fragment sleep continuity and lead to the daytime sleepiness. Because the snoring occurs during sleep, the arousals are unremembered, and the sleepiness can develop so gradually that the patient may forget what normal alertness is like. It is important to interview the patient's spouse or partner. Besides obesity and maleness, other risk factors for OSA are diseases that have an impact on the configuration or effective compliance of the pharyngeal passageway. Recent studies support the clinical intuition that sleep apnea is undesirable. Sleepiness leads to accidents. The hypoxemia occurring during apnea can lead to potentially fatal cardiac dysrhythmias. A number of reports suggest that snoring and sleep apnea are associated with an increased risk of stroke, myocardial ischemia, and infarction. Finally, there are now two papers showing a significantly decreased probability of 5-year survival in patients with symptomatic sleep apnea. The good news is that treatment with tracheostomy or NCPAP improves mortality rates to normal. Approximately 90 per cent of patients can tolerate a night's initial trial with CPAP. Long-term acceptance of CPAP has now been reviewed in a number of studies, and it appears to be about 65 to 70 per cent.
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PMID:Sleep disorders and upper airway obstruction in adults. 219 4

OSA affects approximately 1 per cent of the adult male population and is more common among obese patients. The mechanism for the relationship between obesity and OSA may be mechanical obstruction or hypoxemia. Patients with obesity often have other medical problems that can exacerbate or complicate OSA. The physician should look for other problems such as diabetes, hypertension, and coronary disease while evaluating an obese patient with OSA. Weight loss is important either as a primary therapy or in conjunction with surgical treatment of OSA. Weight loss methods include behavior modification with diet, very low calorie diets with behavior modification, and bariatric surgery. In morbidly obese patients, more dramatic means such as bariatric surgery or very low calorie diets seem to be preferable because of the significant reduction in the length of time it takes for patients to lose weight. Because of a tendency for obese patients to regain weight, it is important to follow the patients long term to prevent the regaining of weight.
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PMID:Obstructive sleep apnea and obesity. 219 6

Reduction in the size of the pharynx and increased pharyngeal airflow resistance have been demonstrated in patients with obstructive sleep apnea (OSA). We evaluated 15 men with severe OSA and 10 nonapneic control subjects matched for age and weight in order to determine if PCSA, inspiratory pharyngeal airflow resistance, and abnormal breathing events during sleep were associated with alterations in the flow-volume relationship and other awake PFTs. Pharyngeal cross-sectional area was determined by CT, and pharyngeal resistance between choanae and epiglottis was measured during quiet awake breathing. In patients with OSA, there was an inverse relationship between the mean cross-sectional area of the oropharynx and the ratio of FEF50%/FIF50% (rs = -0.54; p = 0.03). In all subjects, pharyngeal resistance was inversely related to percentage of predicted values for FEF25-75% (rs = -0.56; p = 0.01). The frequency of apneas during sleep was significantly (p less than 0.05) related to the percentage of predicted values for MVV, TLC, FVC, and PIF. Obesity appears to account for the strength of these relationships. Flow-volume loops and other PFTs did not distinguish patients with OSA from controls.
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PMID:Pulmonary function in obstructive sleep apnea. Relationships to pharyngeal resistance and cross-sectional area. 229 54

During physical examination of patients with suspected obstructive sleep apnea (OSA), a comment is frequently made that they appear to have a short and fat neck. To confirm this subjective impression by objective measurements, we studied a group of 123 patients referred to us because of snoring and suspected OSA, all of whom had nocturnal polysomnography and measurements of external and internal neck circumference. The external neck circumference was measured at the level of the superior border of the cricothyroid cartilage. Internal neck circumferences were calculated from the measurements of pharyngeal, glottic, and tracheal areas obtained by the acoustic reflection technique. Internal pharyngeal circumference was further subdivided into the proximal, middle, and distal thirds. The acoustic technique also permitted us to measure the distance between the teeth and the glottic minimum, which reflects the length of the upper airway. Stepwise multiple linear regression analysis revealed that the apnea/hypopnea index (AHI) correlated only with the external neck circumference, the body mass index, and the internal circumference of the distal pharynx; these three variables accounted for 39% of the variability in AHI. We conclude that the external and internal neck circumferences and the degree of obesity are important predictors of sleep apnea; it is possible that obesity produces its effect via fat in the neck. We speculate that the static pharyngeal size modulated by the dynamic loading of the airway due to the weight of fatty tissue of the neck may contribute to the pathogenesis of OSA.
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PMID:Do patients with obstructive sleep apnea have thick necks? 198 79

The role of weight loss in the therapy of obstructive sleep apnea syndrome (OSAS) was investigated in 23 affected patients with various degrees of obesity (body mass index range 26.6-61.0) free of cranio-facial malformations. Weight loss resulted 18.5 +/- 14.7 (s.d.) kg and was significantly correlated with baseline BMI value (r = 0.94; P less than 0.0001). Weight loss significantly reduced the number of apneas + hypopneas per hour of sleep ((A + H)I) from 66.5 +/- 23.0 to 33.0 +/- 26.2 (P less than 0.0001) and improved the mean of oxygen desaturation peaks during apneas (mSaO2) from 81.9 +/- 6.9 to 87.6 +/- 3.9; P less than 0.001). A significant correlation was found between weight loss and changes in the (A + H)I (r = -0.55; P less than 0.01) and the mSaO2 (r = 0.46; P less than 0.05). The (A + H)I significantly improved in both patients who lost more than 10 kg (basal BMI: 42.3 +/- 10.0) and in those who lost less than 10 kg (basal BMI: 30.2 +/- 2.3), whereas the mSaO2 improved only in the former. Obese patients with moderate to heavy ORL pathological findings had worse pretreatment and final OSAS parameters than those with absent or mild ORL lesions. However, both groups showed a significant, although quantitatively different, improvement of the (A + H)I and mSaO2 after weight loss. Compared to those who were cured or improved after the treatment, patients who failed to obtain significant effects on OSAS clinical presentation also had a significantly higher prevalence of ORL pathology. It is concluded that: (1) weight loss improves parameters and clinical presentation of OSAS in the majority of affected obese patients; (2) a relationship exists between the entity of weight loss and that of improvement of the syndrome; (3) weight loss must be encouraged even in patients with mild to moderate overweight; (4) the presence of ORL pathology may represent a confusing factor in the interpretation of the results obtained after weight loss.
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PMID:Treatment of obese patients with obstructive sleep apnea syndrome (OSAS): effect of weight loss and interference of otorhinolaryngoiatric pathology. 234 Dec 27


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