Epidemiology Of Obstructive Sleep Apnea Research Articles

Epidemiology of obstructive sleep apnea in Chile: a systematic review and meta-analysis

Epidemiology of obstructive sleep apnea in Chile: a systematic review and meta-analysis

Epidemiology of obstructive sleep apnea: What is the contribution of hypertension and arterial stiffness?

Epidemiology of obstructive sleep apnea: What is the contribution of hypertension and arterial stiffness?

Epidemiology of obstructive sleep apnea in older patients with stable cardiovascular disease and chronic kidney disease

Abstract Funding Acknowledgements Type of funding sources: None. Obstructive sleep apnea (OSA) is diagnosed late, especially in older people. The presence of chronic hypoxia and glomerular hypertension decrease renal function in patients with OSAS, which causes the progression of chronic kidney disease (CKD) [3]. The aim of the study was to investigate epidemiological aspects of OSA in older patients with stable cardiovascular disease and chronic kidney disease. Materials and methods 80 older patients with stable cardiovascular disease (43 males, mean age was 67.6 ± 6.1 years) were studied. CKD was diagnosed and classified according to the KDIGO guidelines (2012). OSA was observed according to Clinical Guidelines for Obstructive Sleep Apnea and Insomnia (U.S., 2020). Berlin Questionnaire and Epworth Sleepiness Scale, cardiorespiratory monitoring for screening and diagnosis of OSA were used. Follow-up period was 12 months. Results Chronic kidney disease was observed in 48 (60%) patients. There were no patients with stages 1 and 2 of CKD, stage 3a was detected in 35 (43.8%), 3b - in 10 (12.5%), stage 4 - in 3 (3.8%) patients. Significant daytime sleepiness was observed in every fourth elderly and senile patient with CKD (12; 25%). A high risk of OSA was observed in the majority of patients with CKD - 34 (70.8%). OSA was first diagnosed in 31 (64.5%) patients with CKD. Moreover, the frequency did not depend on gender (p = 0.39) and age (p = 0.48). There were no differences between elderly (60-74 years old) and senile patients (75-89 years old) in the prevalence of OSAS (p> 0.05).More than half had an average degree of OSA (19; 61.3%). Mild and severe degrees were observed with the same frequency in 6 (19.4%) older patients with CKD. Severity of OSA in men and women did not differ (p> 0.05). The average level of oxygen saturation was higher in men: 93.4 (92.4; 94.15) and 92.3 (91.7; 93.1)%, respectively, p = 0.02. There were no differences in the frequency of OSA detection depending on the stage of CKD (p> 0.05). Only 2 (6.5%) patients with OSA and CKD was consulted a somnologist after 12 months of observation Conclusion A high prevalence of OSA was observed in most older patients with stable cardiovascular disease and CKD (34; 70.8%), significant daytime sleepiness was observed in every fourth patient. OSA was first diagnosed in 31 (64.5%) patients with CKD, despite the high risk and clinical symptoms. The severity of OSAS did not depend on gender, age, and the presence of CKD in older patients with stable cardiovascular disease . Subsequently only 2 (6.5%) patients in a sleep consulted, which reflects a low level of overall patient health awareness and availability of quality somnological aid.

The Epidemiology of Obstructive Sleep Apnea in Poland-Polysomnography and Positive Airway Pressure Therapy.

The aim of this study is to provide a brief summary of the epidemiological data on obstructive sleep apnea syndrome (OSAS) diagnosis and therapy in different regions of Poland from 2010 to 2019. We performed a retrospective study in the sleep center of the Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Poland. We requested data from the National Health Service concerning the number of new diagnoses of OSAS, the polysomnographies (PSGs) that were performed, and reimbursements of positive airway pressure (PAP) therapy in each region of Poland in the period 2010–2019. The constant increase in the number of polysomnographies performed and PAP reimbursements suggests the need to create a national network between regional sleep centers to provide proper care for patients with OSAS, and PAP therapy.

TARGETING OSA USING STATE-BASED SURVEILLANCE

TARGETING OSA USING STATE-BASED SURVEILLANCE

0787 Descriptive Epidemiology of Obstructive Sleep Apnea in Children with Autism Spectrum Disorder

0787 Descriptive Epidemiology of Obstructive Sleep Apnea in Children with Autism Spectrum Disorder

0476 THE EPIDEMIOLOGY OF OBSTRUCTIVE SLEEP APNEA AND ASTHMA OR CHRONIC OBSTRUCTIVE PULMONARY DISEASE OVERLAP SYNDROMES IN ONTARIO, CANADA: A POPULATION-BASED COHORT STUDY

Despite their importance, the epidemiology of obstructive sleep apnea (OSA) and asthma (OSA/asthma), and OSA and chronic obstructive pulmonary disease (OSA/COPD) overlap syndromes have not been well studied. We conducted a population-based cohort study to estimate trends in the prevalence and mortality of individuals 35 years and older with OSA/asthma or OSA/COPD in Ontario, Canada. Ontario has a diverse population of about 13 million and a universal health care system that covers most medical services including polysomnography and positive airway pressure (PAP) treatment. Validated health administrative case definitions were used to identify individuals with moderate to severe asthma or COPD. Individuals with OSA were those who received OSA-related PAP treatment. Age- and sex-standardized annual prevalence and mortality rates were estimated and compared from 2009 to 2013 and between conditions. The highest prevalence for both overlaps was in those 50 to 79-years and men. The standardized prevalence increased from 2009 to 2013: for OSA/asthma from 0.38% to 0.54% of the population, for OSA/COPD from 0.23% to 0.31%. Both overlap syndromes were associated with higher mortality than OSA alone. Higher mortality was associated with OSA/asthma compared to asthma alone (OR = 1.09, 95%CI: 1.05–1.13) with larger differences in women and those younger than 50 years. In women but not men, a higher mortality was associated with OSA/COPD compared to COPD alone: OR = 1.06 (1.01–1.11). The standardized all-cause mortality rates among individuals with both overlap syndromes decreased modestly over time. In a large North American population, the prevalence of overlap syndromes was higher in men and middle-aged individuals, and increasing over time. Overlap syndromes were associated with excess mortality in spite of funded PAP treatment, particularly in women and younger people. These findings can alert health care providers and policy makers to the large and increasing burden of overlap syndromes and which high-risk groups are most affected. The Godfrey S Pettit Block Term Grants, University of Toronto; Canadian Respiratory Research Network fellowship training award; Institute for Clinical Evaluative Sciences, which is funded by an annual grant from the Ontario Ministry of Health and Long-term Care.

Obstructive sleep apnea syndrome, continuous positive airway pressure and treatment of hypertension

Obstructive sleep apnea (OSA), present in ~15% of the general population, increases the risks of stroke, heart failure, and premature death. Importantly, individuals with cardiovascular disease have a higher prevalence yet they often have few symptoms to alert clinicians to its presence. OSA with an apnea–hypopnea index (AHI) ≥15events/hour is present in ≥30% of patients with primary hypertension and in up to 80% of those with drug resistant hypertension, suggesting that the neural, hormonal, inflammatory and vascular cascades triggered by OSA may elevate blood pressure chronically. The purpose of this review is to summarize: (1) the epidemiology of OSA and its relation to cardiovascular risk; (2) potential mechanisms by which OSA could promote conditions known to increase the risk of hypertension or contribute to its development and progression; (3) evidence for and against a pro-hypertensive effect of OSA; and, (4) the impact of treatment with continuous positive airway pressure (CPAP) on blood pressure and blood pressure-related morbidities. The prevailing view that the effect of treatment on blood pressure is modest arises from the inability of most contemporary technology to measure accurately the true impact of CPAP on OSA-entrained surges in nocturnal blood pressure. Moreover the exclusive focus on blood pressure, as if this is the principal determinant of cardiovascular event rates in this population, is naïve. The capacity to reduce cardiovascular risk by treating OSA with CPAP likely transcends a simple blood pressure effect; formal testing of this hypothesis will require adequately powered randomized clinical trials.

High prevalence of obstructive sleep apnea in Marfan's syndrome

Objective To review the current evidence about the prevalence of obstructive sleep apnea in patients with Marfan's syndrome, and discuss some proposed potential mechanisms for this relationship. Data sources The data in this review were mainly from Medline and PubMed articles published in English from 1990 to 2013. The search term was “Marfan's syndrome and sleep apnea”. Study selection Clinical evidence about the epidemiology of obstructive sleep apnea in patients with Marfan's syndrome; the mechanism that causes obstructive sleep apnea; interventional therapy for patients with Marfan's syndrome, and coexisting obstructive sleep apnea. Results A high prevalence of obstructive sleep apnea exists in patients with Marfan's syndrome. The potential reasons are craniofacial abnormalities and lax upper airway muscles, which lead to high nasal airway resistance and upper airway collapse. Obstructive sleep apnea mechanically deteriorates aortic dilatation and accelerates progression of aortic aneurysms. The condition is reversible and rapid maxillary expansion and adequate continuous positive airway pressure therapy are possible effective therapies to delay the expansion of aortic diameter in patients with Marfan's syndrome. Conclusions Obstructive sleep apnea is strongly associated with Marfan's syndrome. Craniofacial abnormalities and lax upper airway are the main mechanisms. Untreated obstructive sleep apnea accelerates progression of aortic dissection and rupture. Effective therapies for obstructive sleep apnea could postpone the aortic dilatation in patients with Marfan's syndrome.

Ambulatory Office Visits and Medical Comorbidities Associated with Obstructive Sleep Apnea

(1) Understand the epidemiology of obstructive sleep apnea (OSA) ambulatory office visits in the United States. (2) Quantify the prevalence of comorbid illnesses that are likely to occur in the setting of OSA. From the 2008-2009 National Ambulatory Medical Care Surveys and National Hospital Ambulatory Medical Care Surveys, adult cases with a diagnosis of OSA were extracted. The epidemiology of OSA was determined. The prevalences of comorbid priority illnesses (obesity, asthma, cerebrovascular disease, depression, hypertension, and ischemic heart disease) were also determined. Cross-sectional analysis of a national survey database. Ambulatory care settings in the United States. There were an estimated 4.1 ± 1.2 million annual visits with a diagnosis of OSA (60% ± 3.2% men; mean age, 56.4 ± 0.9 years). There were 419,000 ± 28,000 visits annually to otolaryngologists for OSA. Comorbid illnesses were obesity (23.8% ± 5.2%), asthma (14.3% ± 3.0%), cerebrovascular disease (2.5% ± 1.5%), depression (23.2% ± 2.6%), hypertension 53.8% ± 3.9%), and ischemic heart disease (10.3% ± 3.0%). Adjusting for age, sex, ethnicity, obesity, and race, statistically significant increased odds for the presence of obesity (3.6, P < .001), asthma (2.7, P < .001), depression (2.5, P < .001), and hypertension (2.0, P < .001) with OSA were noted. Increased odds for cerebrovascular disease and ischemic heart disease were not identified (P = .725 and P = .083, respectively). Obstructive sleep apnea is a relatively common diagnosis in ambulatory and otolaryngologic care. It is associated with a significantly increased prevalence of several key priority health care conditions in the United States. Otolaryngologists and health care providers should be aware of these associations, understanding the potentially broad impact of OSA on general health.

Ambulatory Visits and Comorbidity in Obstructive Sleep Apnea

Objective: 1) Understand the epidemiology of obstructive sleep apnea (OSA) ambulatory office visits in the US. 2) Quantify and learn about the prevalence of comorbid illnesses that are likely to occur in the setting of OSA. Method: From the 2008-2009 National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey, adult cases with a diagnosis of OSA were extracted. The epidemiology of OSA was determined. The prevalence of comorbid priority illnesses (obesity, asthma, cerebrovascular disease, depression, hypertension, and ischemic heart disease) was also determined. Results: There were an estimated 8.1 ± 2.4 million office visits with a diagnosis of OSA (60 ± 3.2% male; mean age, 56.4 ± 0.9 years). There were 389 ± 49 thousand visits to otolaryngologists for OSA. Comorbid illnesses were: obesity (23.8 ± 5.2%), asthma (14.3 ± 3.0%), cerebrovascular disease (2.5 ± 1.5%), depression (23.2 ± 2.6%), hypertension 53.8 ± 3.9%), and ischemic heart disease (10.3 ± 3.0%). Adjusting for age, sex, ethnicity, obesity and race, statistically significant increased odds for the presence of obesity (3.6, P &lt; .001), asthma (2.7, P &lt; .001), depression (2.5, P &lt; .001), and hypertension (2.0, P &lt; .001) with obstructive sleep apnea were noted. Increased odds for cerebrovascular disease and ischemic heart disease were not identified ( P &gt; .083). Conclusion: OSA is a common diagnosis in ambulatory and otolaryngologic care. It is associated with a significantly increased prevalence of several key priority healthcare conditions in the United States. Healthcare providers should be aware of these associations understanding the potentially broad impact of OSA on general health.

Obstructive sleep apnea: Not just a sleep disorder

Obstructive sleep apnea (OSA) has long been recognized as a disorder characterized by snoring and frequent cessations of breathing resulting in fragmentation of sleep, which eventually leads to cumulative sleep debt in affected patients. Until two decades ago, snoring and apneas drew attention mainly as a social curiosity and sleep apnea was not thought of as a serious disorder with multisystem involvement. Impairment of quality of work and high incidence of motor vehicle accidents associated with OSA were recognized toward the end of the last century. Since the turn of this millennium physicians have become increasingly aware of the various cardiovascular complications, metabolic disturbances, and neuropsychologic deficits. It has become very clear in the last decade that patients with OSA have a high recurrence of atrial fibrillation after elective cardioversion if their sleep apnea is not treated with continuous positive airway pressure (CPAP). Poor control of diabetes mellitus and resistant hypertension in the setting of OSA has also been recognized and significant progress in our understanding in this area has been accomplished. Unless physicians include sleep in their system review, many cases will go undiagnosed, which will eventually result in cardiovascular complications. Patients are also not readily forthcoming with the symptoms of sleep apnea, as they often assume that symptoms, such as snoring and daytime sleepiness, are not something serious to be discussed with their physician. In this review, the characteristics, the pathophysiology, and epidemiology of OSA are discussed. Furthermore, the mechanisms by which OSA affects the cardiovascular, endocrine, and metabolic functions have been explored.

Obstructive sleep apnea may increase the risk of stroke in AF patients: Refining the CHADS2 score

The significance of stroke as a burdensome cardiovascular outcome has long been recognized. In the United States, it is the third ranking cause of all-cause mortality [ [1] Lloyd-Jones D. Adams R. Carnethon M. et al. Heart disease and stroke statistics–2009 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2009; 119: e21-e181 Crossref PubMed Scopus (2096) Google Scholar ]. While there are classical risk factors for stroke that have been recognized, there is a more recent acknowledgement of the significance of sleep apnea (SA). SA involves repeated cessations of breathing during sleep, which has many detrimental effects. The gold standard for diagnosis is overnight polysomnography. There are two types of SA: central sleep apnea (CSA) and obstructive sleep apnea (OSA). CSA, involves an absence of breathing effort stemming from central dysregulation, while in OSA, efforts are made to breathe but are perturbed by upper airway obstruction [ [2] Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research. The Report of an American Academy of Sleep Medicine Task Force. Sleep. 1999; 22:667–89. Google Scholar ]. OSA is more common and its severity is usually defined by the apnea–hypopnea index (AHI), the number of obstructive apnea and hypopnea episodes per hour of sleep (severe=AHI≥30) [ [2] Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research. The Report of an American Academy of Sleep Medicine Task Force. Sleep. 1999; 22:667–89. Google Scholar ]. The reported prevalence of OSA in adults can be as high as 1 in 5 in Western nations [ [3] Young T. Peppard P.E. Gottlieb D.J. Epidemiology of obstructive sleep apnea: a population health perspective. Am J Resp Crit Care. 2002; 165: 1217-1239 Crossref PubMed Scopus (3282) Google Scholar ]. In addition, an estimated 80% of Americans have undiagnosed SA [ [4] Young T. Evans L. Finn L. Palta M. Estimation of the clinically diagnosed proportion of sleep apnea syndrome in middle-aged men and women. Sleep. 1997; 20: 705-706 Crossref PubMed Scopus (1277) Google Scholar ].

Prevalence and risk factors of obstructive sleep apnea among middle-aged urban Indians: A community-based study

Background The epidemiology of obstructive sleep apnea (OSA) and obstructive sleep apnea syndrome (OSAS) is not well studied among Indians. We sought to determine the prevalence and risk factors of OSA in a middle-aged urban Indian population. Methods We conducted a two-stage, cross-sectional, community-based study in four different socioeconomic zones of the South Delhi district, India, from April 2005 to June 2007. In stage 1, subjects of either gender aged 30–65 yrs were administered a questionnaire by door-to-door survey using systematic random sampling. Subjects that responded were classified as habitual and non-habitual snorers. In stage 2, all the habitual and 10% of randomly selected non-habitual snorers were invited for overnight polysomnographic study. Results Of the 2860 subjects approached, 2505 (88%) completed stage 1. Habitual snoring was present in 452 (18%) subjects. In stage 2, OSA defined as apnea–hypopnea index ⩾5 was observed in 94 (32.4%) of 290 habitual snorers and 3 (4%) of 75 non-habitual snorers. Estimated population prevalence of OSA and OSAS was 9.3% (95% CI 8.2–10.5%) and 2.8% (2.1–3.4%) respectively. On multivariable analysis, male gender (adjusted odds ratio 3.8 [1.7–4.9]), body-mass index ⩾25 kg/m 2 (4.1 [2.0–8.3]), and abdominal obesity (2.2 [1.9–5.3]) were independently associated with the presence of OSA. A linear trend was observed in the prevalence of OSA across the socioeconomic strata. Conclusions OSA is a significant public health problem in the middle-aged Indian population across the socioeconomic spectrum. OSA is associated with some of the well known risk factors for cardiovascular disease.

Epidemiology of obstructive sleep apnea: a population-based perspective

This review summarizes the recent literature on the epidemiology of adult obstructive sleep apnea (OSA) from various population-based studies. Despite methodologic differences, comparisons have yielded similar prevalence rates of the OSA syndrome in various geographic regions and across a number of ethnic groups. Risk factors for OSA including obesity, aging, gender, menopause and ethnicity, are analyzed. We also provide discussion on adverse medical conditions associated with OSA, including hypertension, stroke, coronary artery disease, congestive heart failure, cardiovascular mortality, insulin resistance and neurocognitive dysfunction. Finally, with the progression of the global obesity epidemic, we focus on the economic healthcare burden of OSA and the importance of recognizing the largely undiagnosed OSA population, with an emphasis on strategies to improve access to diagnostic resources.

Puberty and upper airway dynamics during sleep.

The upper airway compensatory response to subatmospheric pressure loading declines with age. The epidemiology of obstructive sleep apnea suggests that sex hormones play a role in modulating upper airway function. Sex hormones increase gradually during puberty, from minimally detectable to adult levels. We hypothesized that the upper airway response to subatmospheric pressure loading decreased with increasing pubertal Tanner stage in males but remained stable during puberty in females. Upper airway dynamic function during sleep was measured over the course of puberty. Normal subjects of Tanner stages 1 to 5. During sleep, maximal inspiratory airflow was measured while varying the level of nasal pressure. The slope of the upstream pressure-flow relationship (SPF) was measured. The SPF correlated with age and Tanner stage. However, the relationship with Tanner stage became nonsignificant when the correlation due to the mutual association with age was removed. Females had a lower SPF than males. In both sexes, the upper airway compensatory response to subatmospheric pressure loading decreased with age rather than degree of pubertal development. Thus, changes in sex hormones are unlikely to be a primary modulator of upper airway function during the transition from childhood to adulthood. Although further studies of upper airway structural changes during puberty are needed, we speculate that the changes in upper airway function with age are due to the depressant effect of age on ventilatory drive, leading to a decrease in upper airway neuromotor tone.

Allergic Rhinitis May Be Important in Snoring Infants

We read with interest the article by Kalra et al, 1 Kalra M LeMasters G Bernstein D et al. Atopy as a risk factor for habitual snoring at age 1 year. Chest. 2006; : 942-946 Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar who found that the prevalence of habitual snoring for 1-year-old children was 15% in a high-risk group for atopy,ie, children born to atopic parents. This prevalence was significantly higher than that reported in older children, 10.9% in 6- to 12-year-old children in Hong Kong, 2 Ng DK Kwok KL Cheung JM et al. Prevalence of sleep problems in Hong Kong primary school children: a community-based telephone survey. Chest. 2005; 128: 1315-1323 Abstract Full Text Full Text PDF PubMed Scopus (110) Google Scholar and 10 to 14% in < 6-year-olds in Europe and the United States. 3 Young T Peppard PE Gottlieb DJ Epidemiology of obstructive sleep apnea: a population health perspective. Am J Respir Crit Care Med. 2002; 162: 1217-1239 Crossref Scopus (3328) Google Scholar This higher prevalence is most likely due to the fact that 29% of this group of infants were atopic, and it is not surprising that Kalra et al 1 Kalra M LeMasters G Bernstein D et al. Atopy as a risk factor for habitual snoring at age 1 year. Chest. 2006; : 942-946 Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar found that the presence of atopy increased the risk of habitual snoring (odds ratio, 2.0; 95% confidence interval, 1.2 to 3.0), a common symptom of obstructive sleep apnea syndrome (OSAS). 4 Chau KW Ng DKK Kwok CKL et al. Clinical risk factors for obstructive sleep apnea in children. Singapore Med J. 2003; 44: 570-577 PubMed Google Scholar This was similar to previous findings in Hong Kong, 2 Ng DK Kwok KL Cheung JM et al. Prevalence of sleep problems in Hong Kong primary school children: a community-based telephone survey. Chest. 2005; 128: 1315-1323 Abstract Full Text Full Text PDF PubMed Scopus (110) Google Scholar when we found allergic rhinitis to be a significant risk factor for witnessed apnea with an adjusted odds ratio of 2.19, another symptom of OSAS as well as in the United States. 5 McColley SA Carroll JL Curtis S et al. High prevalence of allergic sensitization in children with habitual snoring and obstructive apnea. Chest. 1997; 111: 170-173 Abstract Full Text Full Text PDF PubMed Scopus (172) Google Scholar It is unfortunate that Kalra et al 1 Kalra M LeMasters G Bernstein D et al. Atopy as a risk factor for habitual snoring at age 1 year. Chest. 2006; : 942-946 Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar did not report the prevalence of nasal symptoms in their cohort, as the data would have shed light on the mechanisms that link habitual snoring and atopic status, possibly allergic rhinitis. Other important data that were not reported were the parts played by individual allergens, especially the airborne allergens vs food allergen. These data would help determine whether the inhaled route or the ingested route is important in the habitual snoring infants. In the study of Kalra et al, 1 Kalra M LeMasters G Bernstein D et al. Atopy as a risk factor for habitual snoring at age 1 year. Chest. 2006; : 942-946 Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar the definition of positive atopic status for egg white and whole milk was wheal ≥ 3 cm than the negative control, and this would be associated with a high false-positive rate. 6 Sporik R Hill DJ Hosking CS Specificity of allergen skin testing in predicting open food challenges to milk, egg and peanut in children. Clin Exp Allergy. 2000; 30: 1495-1498 Crossref PubMed Scopus (472) Google Scholar ResponseCHESTVol. 131Issue 1PreviewWe thank Ng et al for their interest in our article.1They raise concern about lack of data on nasal symptoms and our definition for positive skin-prick test results. Using the rhinitis definition of a positive parent report to the question “In the past 12 months, has your child ever had a problem with sneezing, or a runny, or a blocked nose when he/she did not have a cold or flu?” we found a strong association between rhinitis and habitual snoring (p < 0.001) in our cohort of 681 infants. In multivariate logistic regression model with habitual snoring as the dependent variable, the adjusted odds ratio for rhinitis was 2.5 (confidence interval, 1.7 to 4.0) and atopy (defined as positive skin-prick test result to an aeroallergen or food allergen was 1.9 (confidence interval, 1.2 to 2.9). Full-Text PDF

Pharyngeal resistance in normal humans: influence of gender, age, and obesity.

Investigation into the etiology of obstructive sleep apnea is beginning to focus increasing attention on upper airway anatomy and physiology (patency and resistance). Before conclusions concerning upper airway resistance in these patients can be made, the normal range of supraglottic and, more specifically, pharyngeal resistance needs to be better defined. We measured supraglottic and pharyngeal resistances during nasal breathing in a normal population of 35 men and women. Our technique measured epiglottic pressure with a balloon-tipped catheter, choanal pressure using anterior rhinometry, and flow with a sealed face mask and pneumotachograph. Resistance was measured at a flow rate of 300 ml/s during inspiration. Men had a mean pharyngeal resistance (choanae to epiglottis) of 4.6 +/- 0.8 (SE) cmH2O X l-1 X s, whereas women demonstrated a significantly (P less than 0.01) lower value, 2.3 +/- 0.3 cmH2O X l-1 X s. Supraglottic resistance was also higher in men (P = 0.01). Age (r = 0.73, P less than 0.01) correlated closely with pharyngeal resistance in men, but no such correlations could be found in women. These results may have implications in the epidemiology of obstructive sleep apnea.