Alex Clerk

Upper Airway Sleep-Disordered Breathing in Women

Most surveys of the obstructive sleep apnea syndrome have emphasized the predominance of the syndrome in men, and the few reports [1-3] describing adult women with this syndrome have emphasized its frequent association with massive obesity. Previous reports have suggested that the appearance of the obstructive sleep apnea syndrome is 10 to 20 times more common in men than in women. Recently, however, a survey of the general population aged 30 to 60 years by Young and colleagues [4] concluded that sleep-disordered breathing or obstructive sleep apnea associated with excessive daytime sleepiness has a prevalence of 4% in middle-aged men and of 2% in middle-aged women; Gislason and colleagues [5] estimated the prevalence at 2.5% for women in Iceland aged 40 to 59 years. The discrepancy between previous estimates of the prevalence of sleep-disordered breathing in women and these recent reports suggests that sleep-disordered breathing in women is underdiagnosed. We studied the clinical presentation and consequences of sleep-disordered breathing in a large sample of women seen during the past 4 years at the Stanford Sleep Disorders Clinic for symptoms of excessive daytime sleepiness. Methods Participants All women 18 years of age and older who contacted the clinic between 1988 and 1993 with symptoms of daytime tiredness, daytime fatigue, or daytime sleepiness were identified using our computerized clinic database. Inclusion Criteria For study inclusion, participants must have had a complete sleep-wake evaluation and a complete report in their chart that included the results of polygraphic evaluation. All participants included in our study had daytime sleepiness, based on either a score of 9 or more on the Epworth sleepiness scale [6, 7] or a score of 8 minutes or less on the multiple sleep latency test [8]. Nocturnal recordings included an electroencephalogram, an electrooculogram, a chin and a leg electromyogram (one lead), measurements of body position, and monitoring of respiration. Breathing patterns during sleep had to have indicated the presence of partial or complete upper airway obstruction. Initially, we looked for obstructive patterns that lasted 10 seconds and for a respiratory disturbance index (the number of apneas and hypopneas per hour of sleep) of 5 or more. In 1991, however, it was shown that clinical consequences could be seen with a respiratory disturbance index of less than 5, even in the absence of classically defined hypopneas. In this group of affected participants (with a respiratory disturbance index < 5), flow remains more or less constant, but breathing effort (as reflected by esophageal pressure) is substantially increased, leading to arousals on the electroencephalograms (the upper airway resistance syndrome) [9]. From this point on, we included participants with obstructive patterns of a shorter duration (one to two obstructed breaths) that induced sleep disturbances and daytime symptoms but who had a respiratory disturbance index of less than 5. The abnormal breathing patterns may have been shown by different means, from the use of complex protocols involving a facemask and pneumotachometer to simpler protocols that used measurements of esophageal pressure (Pes) with inductive respiratory plethysmography, monitoring of airflow, pulse oximetry, microphone monitoring, and intercostal electromyography (Figure 1). The minimum accepted protocol for inclusion involved monitoring of airflow, inductive plethysmography, and pulse oximetry, with the addition of Pes measurements after 1991. Finally, participants had to have shown clinical improvement in response to treatment using nasal continuous positive airway pressure (or nasal bilevel positive airway pressure in obese participants with a body mass index > 36.0 kg/m2). Figure 1. Polygraph showing a progressive increase in respiratory effort over time in a woman with symptoms of sleep-disordered breathing. Exclusion Criteria After reviewing their chart and test results, we excluded patients with sleepiness, a history of cataplexy, and two or more periods of sleep onset with rapid eye movement on the multiple sleep latency test. These patients were diagnosed as having narcolepsy. Patients with sleepiness and specific organic disorders (repetitive nocturnal epileptic seizures, brain tumor, neuromuscular disorders, untreated hypothyroidism) were also excluded. Patients with sleepiness and specific congenital or genetic defects or both (for example, trisomy 21 and substantial craniomandibular abnormalities such as the Hurler, the Hunter, the Traecher-Collin, and the Pierre Robin syndromes and other neurocrestopathies) were excluded even if their daytime sleepiness was related to an upper airway problem during sleep. Patients with major, noncongenital craniofacial deformities (particularly those associated with mandibular involvement) were also excluded, as were patients with psychiatric mood disorders in whom daytime somnolence was clearly a symptom of depression. All other participants 18 years and older were considered for the study and had polygraphic investigation. Selection of Controls Women with Insomnia We selected 60 women with insomnia, aged 18 years or older, who were seen during the same period as the index cases to serve as a control group. Use of this group as a control allowed us to compare the severity of the symptoms of these two groups of women with different sleep disorders. The control participants reported insomnia of at least 6 months duration; all were diagnosed with psychophysiologic insomnia on the basis of interviews, questionnaires, sleep logs, actigraphy, and nocturnal polygraphic recordings [10]. The control group was subdivided into six age groups (18 to 30 years, 31 to 40 years, 41 to 50 years, 51 to 60 years, 61 to 70 years, and > 70 years). Ten women were in each age group. Women with insomnia were examined successively in order of first clinic visit. When a woman met the criteria for any group, she was selected as an appropriate control for the breathing disorders group. The upper limit of normal weight for women in the control and index groups was defined as 26.8 kg/m2 [11]. A participant was considered overweight if her body mass index was more than 27.0 kg/m2 [11]. Participants in the control and sleep-disordered breathing groups were matched for weight on the basis of the above classifications and for menopausal status. Exact matching for obesity was difficult. Our two most obese controls with insomnia had body mass indices of 35.0 kg/m2 and 32.5 kg/m2,respectively, whereas our heaviest case patient with sleep-disordered breathing had a body mass index of 59.0 kg/m2. Men with Insomnia We selected 100 men who had been diagnosed during the past 3 years with upper airway sleep-disordered breathing as a second control group. Controls in this group met the same inclusion and exclusion criteria as female participants. Male controls were matched with case patients for body mass index (2 kg/m2) and respiratory disturbance index (<5 or 5). Exact matching for obesity was easy; we were able to match the men with the womens index group for highest body mass index. Geographic Distribution of Participants The Stanford Sleep Disorders Clinic has a high visibility locally and nationally and has frequent exposure in the media. Forty percent of the patients seen at the clinic are self-referred. These patients come to the Clinic for various reasons: Some have already seen sleep specialists and want second opinions, some are seeking different treatment options, and some have used the telephone book and come because our location is convenient. Twenty-five percent of our patients are referred by surgeons after consultation for a snoring problem; 35% are referred by general practitioners, internists, and pulmonary physicians who may be part of a health maintenance organization or a preferred provider organization that includes Stanford Medical Center as part of its referral list. Collected Variables and Analysis Data on the three groups of participants were collected from interviews. We used the Sleep Questionnaire and Assessment of Wakefulness, a previously validated questionnaire covering sleep-wake symptoms, past and present sleep-wake history, medical history, and drug intake [12, 13]. The sleep specialist reviewed answers to the questionnaire at the time of the patients interview. Demographic, familial, and social histories are also included in this sleep questionnaire and in the clinic administrative questionnaire, and these data were used in our analysis. Body mass index [14], neck circumference [15-18], and fatty distribution [19] were taken from records of the initial evaluation (done within 1 month of polysomnography). Upper airway anatomy was examined, and a diagram of anatomic abnormalities of the region was made on a standard form. In women, hormonal status was derived from their histories, and, if necessary, a follicle-stimulating hormone test was done after determining whether the women were receiving hormonal treatment (including birth control pills or estrogen as prophylaxis for osteoporosis). Daytime sleepiness indices and sleep variables for statistical analysis before and after treatment were collected from the monitored nights. Data and Statistical Analyses All participants were given a number, and their data were processed anonymously. Histograms were generated to describe the overall group of participants. Simple, descriptive statistics were generated using the Statview statistical computer package (Abacus Concepts, Inc., Berkeley, California). Correlation matrices were obtained. We did linear and multiple regression analyses to evaluate the effect of independently collected variables on dependent variables, such as respiratory disturbance index. Analysis of variance (ANOVA) was used for analyses of noncontinuous variables, and ANOVAs were also used, in conjunction with nonparametric statistics, to compare d

A Cost-Effective and Rational Surgical Approach to Patients With Snoring, Upper Airway Resistance Syndrome, or Obstructive Sleep Apnea Syndrome†

The past decade has seen several innovations in the surgical techniques available for treatment of patients with sleep‐disordered breathing. Outpatient techniques such as laser‐assisted uvulopalatoplasty (LAUP) and more aggressive procedures designed to address hypopharyngeal and base of tongue obstruction (genioglossus advancement and hyoid myotomy) have been developed and proven successful. We describe the efficacy of LAUP for snoring (72.7%), upper airway resistance syndrome (81.8%), and mild (mean[±SD] respiratory disturbance index [RDI] = 12 ± 8.1) obstructive sleep apnea (41.7%) in 56 patients who underwent 132 LAUP procedures in a 26‐month period. Thirty‐two patients with more significant obstructive sleep apnea (mean RDI = 41.8 ± 23.1) underwent multilevel pharyngeal surgery consisting of genioglossus advancement and hyoid myotomy combined with uvulopalatopharyngoplasty. The surgical success rate in this group of patients was 85.7% when commonly accepted criteria were applied. We recommend a stratified surgical approach to patients with sleep‐disordered breathing. Progressively worse airway obstruction marked by multilevel pharyngeal collapse and more severe sleep‐disordered breathing is treated with incrementally more aggressive surgery addressing multiple areas of the upper airway.

Cognitive function in patients with sleep apnea after acute nocturnal nasal continuous positive airway pressure (CPAP) treatment: sleepiness and hypoxemia effects.

Patients with sleep apnea are typically hypersomnolent during the daytime and may demonstrate higher order cognitive dysfunction. A persistent problem in interpreting impaired neuropsychological test performance in such patients is whether the observed deficits can be explained wholly by impaired vigilance. We examined 37 sleep apnea patients prior to and immediately subsequent to successful sleep apnea treatment with nasal continuous positive airway pressure (CPAP). Patients were evaluated immediately after morning awakening in the sleep lab. A brief neuropsychological evaluation, was administered at that time. Following this, alertness was measured with a 30-min polysomnographically determined sleep latency test. Both test (approximately 50 min in duration) were performed once following a baseline (diagnostic) night in the sleep lab and once in the morning following a CPAP (therapeutic) night in the lab. Subgroup analyses indicted that while vigilance impairment can account for some of the decreased test performance seen in sleep apnea (auditory verbal learning) the effects of severe nocturnal hypoxemia appear to affect other function (sustained attention in repetitive arithmetic calculations) that were not easily modified by treatment. Thus, performance on the recall trial of the Rey Auditory Verbal Learning Test increased from pre-CPAP to post-CPAP for the increased alertness group but decreased significantly for the decreased alertness group. On the Wilkinson Addition Test, non-hypoxemic patients showed statistically significant improvement in problems correctly solved from pre-CPAP to post-CPAP, but the hypoxemic patients showed only a marginal increase. These results are compatible with other studies suggesting that patients having sleep apnea may incur deficits as a result of both decreased vigilance and hypoxemia, and that at least some of these deficits are immediately reversible.

Characterization of postoperative edema following laser-assisted uvulopalatoplasty using MRI and polysomnography : implications for the outpatient treatment of obstructive sleep apnea syndrome

Laser‐assisted uvulopalatoplasty (LAUP) has been introduced as an alternative to uvulopalatopharyngoplasty for the treatment of snoring. Despite limited study, the use of this procedure has been expanded to include patients with obstructive sleep apnea syndrome. Although the potential cost‐savings of performing sleep apnea surgery on an outpatient basis are self‐evident, concern exists regarding the safety of this practice.

Recognition and Surgical Management of the Upper Airway Resistance Syndrome

Patients with upper airway resistance syndrome (UARS) have clinical signs and symptoms of excessive daytime somnolence (EDS) in the absence of obstructive sleep apnea. These patients have increased upper airway resistance, reflected by an elevated intrathoracic pressure measurement, despite a normal respiratory disturbance index (RDI). Physical findings often include excessive palatal tissue and narrowing of the oropharynx and hypopharynx.

Nasal obstruction and obstructive sleep apnea: a review.

Several groups of investigators have assessed the impact of nasal obstruction on the obstructive sleep apnea syndrome. These studies evaluated patients with either naturally occurring partial nasal obstruction (e.g., allergic rhinitis, septal deviation) or experimentally induced nasal occlusion. The results of these studies are summarized and discussed in this article.

Daytime somnolence: therapeutic approaches

Excessive daytime somnolence is a major neurological problem involving about 4% of the general population. Its treatment is based on accurate etiological dissection. Sleep-disordered breathing is a major cause of EDS. Stimulant medication is helpful in many other instances.

Gender differences in sleep architecture in sleep apnoea syndrome

SUMMARY  This study compared sleep architecture in women and men with sleep apnoea syndrome. Women (n= 126) had longer sleep latencies, greater amounts of slow wave sleep, and fewer awakenings during the night than men (n= 181), despite no differences in age, RDI (Respiratory Disturbance Index) or oxygen saturation. In a subgroup of men and women treated with nasal CPAP, gender differences generally persisted. There was no difference in the complaint of daytime sleepiness between the groups, but the women reported more fatigue during the day than the men, as well as complaining about more sleep disturbance at night. We interpret these differences in terms of known gender differences in sleep architecture and sleep complaints.