Discrimination Predicts Suboptimal Adherence to CPAP Treatment and Mediates Black-White Differences in Use

BACKGROUND

Although racial and ethnic differences in CPAP adherence for OSA are widely established, no studies have examined the influence of perceived racial discrimination on CPAP usage, to our knowledge.

RESEARCH QUESTION

(1) Do Black adults with OSA report experiencing greater amounts of discrimination than non-Hispanic White adults? (2) Is discrimination associated with poorer CPAP adherence over time, independent of self-identified race? (3) Does discrimination mediate the relationship between self-identified Black race and CPAP usage?

STUDY DESIGN AND METHODS

In this prospective study, Black and non-Hispanic White adults with OSA initiating CPAP were enrolled from two sleep centers and completed questionnaires including sociodemographics, perceived discrimination, daytime sleepiness, insomnia symptoms, and depressive symptoms. Perceived discrimination was measured using the Everyday Discrimination Scale (EDS). Black and White group comparisons for baseline sociodemographic variables, sleep symptoms, and perceived discrimination were performed with Student t test or χ2/Fisher exact test, as appropriate. A linear regression model was completed with self-identified Black race and EDS total score as the primary independent variables of interest and mean daily CPAP usage at 30 and 90 days serving as the dependent outcomes. This regression modeling was repeated after adjusting for psychosocial variables known to be associated with CPAP usage. EDS total score was explored as a potential mediator of the association between self-identified Black race and mean daily CPAP adherence at 30 and 90 days.

RESULTS

The sample for this analysis consisted of 78 participants (31% female, 38% Black) with a mean age of 57 ± 14 years. Sixty percent of the Black adults reported they experienced racial discrimination at least a few times each year. Relative to White adults, Black adults were also more likely to indicate more than one reason for discrimination (27% vs 4%, P = .003). Adjusting for discrimination, self-identified Black race was associated with 1.4 (95% CI, -2.3 to -0.4 h; P = .006) and 1.6 (95% CI, -2.6 to -0.6 h; P = .003) fewer hours of mean daily CPAP usage at 30 and 90 days, respectively. In the fully adjusted model, a 1-unit change in the total discrimination score (more discrimination) was associated with a 0.08-h (95% CI, 0.01-0.15 h; P = .029) and 0.08-h (95% CI, 0.01-0.16 h; P = .045) change in mean daily CPAP usage at 30 and 90 days, respectively.

INTERPRETATION

Adults with OSA who encountered racial discrimination experienced greater decrement in CPAP usage than those who did not experience racial discrimination.

The Effect of Self-Reported Visual Impairment and Sleep on Cognitive Decline: Results of the Hispanic Community Health Study/Study of Latinos

BACKGROUND

Visual impairment could worsen sleep/wake disorders and cognitive decline.

OBJECTIVE

To examine interrelations among self-reported visual impairment, sleep, and cognitive decline in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Miami-site.

METHOD

HCHS/SOL Miami-site participants ages 45-74 years (n = 665) at Visit-1, who returned for cognitive test 7-years later (SOL-INCA). Participants completed the National Eye Institute Visual Functioning Questionnaire (NEI-VFQ), validated sleep questionnaires and test for obstructive sleep apnea (OSA) at Visit-1. We obtained verbal episodic learning and memory, verbal fluency, processing speed, and executive functioning at Visit-1 and at SOL-INCA. Processing speed/executive functioning were added to SOL-INCA. We examined global cognition and change using a regression-based reliable change index, adjusting for the time lapse between Visit-1 and SOL-INCA. We used regression models to test whether 1) persons with OSA, self-reported sleep duration, insomnia, and sleepiness have an increased risk for visual impairment, 2a) visual impairment is associated with worse cognitive function and/or decline, and 2b) sleep disorders attenuate these associations.

RESULT

Sleepiness (β= 0.04; p < 0.01) and insomnia (β= 0.04; p < 0.001) were cross-sectionally associated with visual impairment, adjusting for sociodemographic characteristics, behavioral factors, acculturation, and health conditions. Visual impairment was associated with lower global cognitive function at Visit-1 (β= -0.16; p < 0.001) and on average 7-years later (β= -0.18; p < 0.001). Visual impairment was also associated with a change in verbal fluency (β= -0.17; p < 0.01). OSA, self-reported sleep duration, insomnia, and sleepiness did not attenuate any of the associations.

CONCLUSION

Self-reported visual impairment was independently associated with worse cognitive function and decline.

Primary aldosteronism and obstructive sleep apnea: A single-center cross-sectional study of the Japanese population

A recent report demonstrated that the prevalence of obstructive sleep apnea (OSA) is 67.6% among Caucasian and Chinese patients with primary aldosteronism (PA). Moreover, the report showed a significant association between plasma aldosterone concentration (PAC) and the severity of OSA in Caucasian patients. However, no studies have examined the prevalence of OSA with PA or the association of its severity with PAC in the Japanese population. We retrospectively evaluated the prevalence and severity of OSA in 71 newly diagnosed Japanese patients with PA. Thirty-nine (55%) of the 71 patients were diagnosed with OSA, and 69% of PA patients with OSA reported snoring. No correlation was found between the respiratory event index (REI), snoring index, and PAC and plasma renin activity (PRA). In contrast, REI correlated significantly with body mass index (BMI), which was significantly correlated with PRA. In conclusion, although the severity of OSA did not correlate with PAC and PRA, there was a high prevalence of OSA among Japanese patients with PA. Moreover, the severity of OSA was strongly affected by BMI. Thus, the examination of OSA in patients with PA and the proper management of OSA might be important for the Japanese population.

C-reactive Protein and Risk of OSA in Four US Cohorts

BACKGROUND

Individuals with OSA have elevated levels of inflammatory markers, but no prospective study has examined the role of inflammation in the development of OSA.

RESEARCH QUESTION

Is C-reactive protein (CRP) prospectively associated with risk of developing OSA?

STUDY DESIGN AND METHODS

We followed 1,882 women from the Nurses' Health Study (NHS) (2002-2012), 3,854 women from Nurses' Health Study II (NHSII) (1995-2013), 3,075 men from the Health Professionals Follow-up Study (HPFS) (1996-2012), and 1,919 women and men from the Multi-Ethnic Study of Atherosclerosis (MESA) (2000-2012) who did not have diagnosed OSA at baseline and for whom CRP levels were available. In NHS/NHSII/HPFS, physician-diagnosed OSA was self-reported. In MESA, at-home polysomnography was performed and OSA was identified as an apnea-hypopnea index ≥ 30. Logistic regression was used to estimate the OR for OSA risk according to baseline CRP level, adjusted for multiple inflammation-related factors.

RESULTS

After multivariable adjustment not including BMI, the pooled OR for OSA risk per doubling of baseline CRP level was 1.24 (95% CI, 1.18-1.30). Additional adjustment for BMI substantially attenuated the association (pooled OR, 1.07; 95% CI, 1.01-1.12). The fully adjusted association was consistently stronger in individuals < 55 vs ≥ 55 years of age (P interaction = .01), in individuals with BMI < 25 vs ≥ 25 kg/m² (P interaction = .02), and in pre- vs postmenopausal women (P interaction = .002). CRP was more strongly associated with risk of OSA associated with excessive daytime sleepiness, high airway collapsibility, and low arousal threshold (P heterogeneity < .05).

INTERPRETATION

Higher CRP was prospectively associated with increased OSA risk, particularly among younger individuals, underweight/normal-weight individuals, or premenopausal women. The differential associations by OSA phenotype/endotype suggest possible mechanisms through which inflammation operates to modulate OSA risk. Given our reliance on a single CRP level measured a decade before OSA assessment, future studies with repeated CRP measurements are warranted to confirm these prospective associations.

Prevalence and Risk of Obstructive Sleep Apnea and Arterial Hypertension in the Adult Population in Poland: An Observational Subset of the International Prospective Urban Rural Epidemiology (PURE) Study

Obstructive sleep apnea (OSA) is a common breathing disorder affecting millions of people worldwide. The disorder is connected with serious consequences including hypertension, myocardial infarction, arrhythmias, coronary disease, cardiac insufficiency, stroke, transient ischemic attack, and cognitive decline. Epidemiological data assessing the prevalence of OSA in different countries vary in methodology, size, and characteristics of population chosen and thus are hardly comparable. There are very few reports on the prevalence of OSA and on the diagnostic accuracy of sleep questionnaires available in Poland. In this report we present the analysis of the prevalence of, and risk factors for OSA in the Polish adult population consisting of 613 community-based subjects (227 men and 386 women). The study was based on the STOP-BANG questionnaire, a validated Screening Tool for OSA in primary care. It is a part of Polish subset of the Prospective Urban Rural Epidemiology (PURE) study, an ongoing population cohort study of individuals from urban and rural communities from 21 countries. We took into account age, gender, body mass index (BMI), and antihypertensive treatment. The findings are that over one half of the Polish population investigated had a moderate to high risk of OSA (66.5% of men and 60.1% of women). After the adjustments for age, gender, and BMI we noticed a dose-response relationship between arterial blood pressure behavior and OSA. The association was significant among women, but not men. Based on previous studies we can assume that one half of this high risk group would be further diagnosed for OSA. This study, the first large scale screening for OSA in Poland, shows a substantial, much higher than previously appreciated, prevalence of risk for OSA in the population at large.

Effect of the Interaction between Obstructive Sleep Apnea and Lipoprotein(a) on Insulin Resistance: A Large-Scale Cross-Sectional Study

Both obstructive sleep apnea (OSA) and decreased serum lipoprotein(a) (Lp(a)) concentrations are associated with insulin resistance. However, their interaction effect on insulin resistance has never been investigated. Therefore, we performed a cross-sectional study on OSA-suspected Chinese Han participants. Laboratory-based polysomnographic variables, biochemical indicators, anthropometric measurements, and medical history were collected. Linear regression and binary logistic regression analyses with interaction terms were used to investigate the potential effects of the interaction between the severity of OSA (assessed by the apnea-hypopnea index (AHI)) and Lp(a) concentrations on insulin resistance (assessed by the homeostasis model assessment of insulin resistance (HOMA-IR)), after adjusting for potential confounders including age, gender, body mass index, waist-to-hip circumference ratio, mean arterial pressure, smoking status, drinking status, and lipid profiles. A total of 4,152 participants were enrolled. In the OSA-suspected population, AHI positively correlated with insulin resistance and serum Lp(a) concentrations independently and inversely correlated with insulin resistance. In addition, the interaction analysis showed that the linear association between lgAHI and lgHOMA-IR was much steeper and more significant in subjects with relatively low Lp(a) concentrations, suggesting a significant positive interaction between lgLp(a) and lgAHI on lgHOMA-IR (P = 0.013). Furthermore, the interaction on a multiplicative scale also demonstrated a significant positive interaction (P = 0.044). A stronger association between AHI quartiles and the presence of insulin resistance (defined as HOMA-IR > 3) could be observed for participants within lower Lp(a) quartiles. In conclusion, a significant positive interaction was observed between OSA and decreased Lp(a) with respect to insulin resistance. This association might be relevant to the assessment of metabolic or cardiovascular disease risk in OSA patients.

Associations between polysomnography and actigraphy-based sleep indices and glycemic control among those with and without type 2 diabetes: the Multi-Ethnic Study of Atherosclerosis

Study Objectives

To examine the associations of sleep measures with hemoglobin A1c (HbA1c) among individuals with and without type 2 diabetes.

Methods

Data were from 2049 Multi-Ethnic Study of Atherosclerosis participants taking part in a sleep ancillary study. Cross-sectional linear regression models examined associations of actigraphy estimates of sleep (sleep duration, variability, and maintenance efficiency) and polysomnography measures (obstructive sleep apnea [OSA] and hypoxemia) with HbA1c, stratified by diabetes status. Primary models were adjusted for demographics, lifestyle behaviors, and obesity.

Results

Among individuals with diabetes (20 per cent population), those who slept <5 hr/night had greater HbA1c than those who slept 7-8 hr/night (7.44 vs. 6.98 per cent, ptrend = 0.04), with no attenuation of associations after adjusting for OSA/hypoxemia. In women with diabetes, but not men, those in the lowest quartile of sleep maintenance efficiency had greater HbA1c than those in the highest quartile of sleep maintenance efficiency (7.60 vs. 6.97 per cent, ptrend < 0.01). Among those without diabetes, individuals with severe OSA or in the highest quartile of hypoxemia had significantly greater HbA1c than those without OSA or who were in the lowest quartile of hypoxemia (5.76 vs. 5.66 per cent, ptrend = 0.01; 5.75 vs. 5.66 per cent, ptrend < 0.01, respectively). Associations did not meaningfully differ by race/ethnicity.

Conclusions

Among individuals with diabetes, HbA1c was significantly higher in men and women with short sleep duration and in women with poor sleep maintenance efficiency, suggesting a role for behavioral sleep interventions in the management of diabetes. Among individuals without diabetes, untreated severe OSA/hypoxemia may adversely influence HbA1c.

Prevalence and correlates of obstructive sleep apnea among African Americans: the Jackson Heart Sleep Study

Study Objectives

African Americans have been under-represented in obstructive sleep apnea (OSA) research. This study determined the prevalence and correlates of OSA overall and by sex among African Americans in the Jackson Heart Sleep Study.

Methods

Participants (N = 852) underwent a type 3 in-home sleep apnea study, 7 day wrist actigraphy and completed standardized measurements and questionnaires. OSA was defined as an apnea-hypopnea index (AHI) of ≥15, where hypopneas were defined as ≥ 4% associated desaturation. Physician diagnosis of OSA was self-reported. Logistic regression models were fit to determine the associations of demographics, socioeconomic status, sleep symptoms, actigraphy-based sleep, body mass index (BMI), and comorbidities with OSA.

Results

Average age was 63.1 (standard deviation = 10.7), 66% were female, and mean BMI was 32.0 (6.9) kg/m2. Approximately 24% had an AHI ≥ 15; of those, 5% had a physician diagnosis of OSA. Prevalence of OSA increased across BMI categories, but not age groups. Men had a 12% higher prevalence of OSA compared with women, p < 0.01. Older age, male sex, higher BMI, larger neck circumference, and report of habitual snoring were independently associated with higher odds of OSA, all p < 0.05. Associations between sleep symptoms and OSA were similar for men and women. Sleepiness and waist circumference were not associated with OSA.

Conclusions

There was a high prevalence of objectively measured but undiagnosed OSA in this sample of African Americans. Snoring, BMI, and neck circumference were important markers of OSA for men and women. Our results suggest that screening tools that incorporate information on sleepiness and waist circumference may be suboptimal in this population.

Culturally tailored, peer-based sleep health education and social support to increase obstructive sleep apnea assessment and treatment adherence among a community sample of blacks: study protocol for a randomized controlled trial

BACKGROUND

Compared to whites, blacks are at increased risk for obstructive sleep apnea (OSA) yet less likely to adhere to physician-recommended sleep assessment and treatment. Poor OSA health literacy and lack of social support to navigate the current healthcare system are two potential barriers to adequate OSA care. This study is designed to address these barriers by evaluating the effectiveness of a peer-based sleep health education program on adherence to OSA assessment and treatment among blacks at risk for OSA.

METHOD/DESIGN

In a two-arm, randomized controlled trial, we will ascertain the effectiveness of peer-based sleep health education and social support in increasing OSA evaluation and treatment rates among 398 blacks at low to high OSA risk. Participants at risk of OSA will receive quality controlled, culturally, and linguistically tailored peer education based on Motivational Enhancement principles over a period of 12 months. During this 12-month period, participants are encouraged to participate in a sleep home study to determine risk of OSA and, if found to be at risk, they are invited to undergo a diagnostic sleep assessment at a clinic. Participants who are diagnosed with OSA and who are prescribed continuous positive airway pressure treatment will be encouraged, through peer-based education, to adhere to recommended treatment. Recruitment for the project is ongoing.

DISCUSSION

The use of a culturally tailored sleep health education program, peer health educators trained in sleep health, and home-based sleep assessment are novel approaches in improving OSA assessment and treatment adherence in blacks who are significantly at risk for OSA. Empirical evidence from this trial will provide clinical and population level solutions on how to improve and increase assessment and treatment of OSA among blacks.

TRIAL REGISTRATION

NCT02427815 . Registered on 20 April 2015. ClinicalTrials.gov title: Sleep Health Education and Social Support Among Blacks With OSA.

Association between Obstructive Sleep Apnea and Cardiovascular Risk Factors: Variation by Age, Sex, and Race. The Multi-Ethnic Study of Atherosclerosis

RATIONALE

The association between obstructive sleep apnea (OSA) and cardiovascular disease (CVD) is complex, bidirectional, and may vary across groups. Understanding which cardiovascular risk factors vary in their relationship to OSA across population groups may improve knowledge of OSA-related CVD susceptibility.

OBJECTIVES

To better understand the heterogeneity of associations, we assessed whether associations of OSA with cardiovascular risk factors vary by age, sex, and race/ethnicity.

METHODS

We performed cross-sectional analyses of 1,344 Multi-Ethnic Study of Atherosclerosis participants who underwent overnight full polysomnography, assays of fasting blood, and assessments of cardiovascular risk factors. Risk factors considered were blood pressure, glucose/lipid concentrations, white blood cell (WBC) total and subset counts, and cystatin C. The outcome was the apnea-hypopnea index (AHI). Linear regression analyses with tests for interactions were conducted.

RESULTS

The sample had a mean age of 68 ± 9 years. Forty-seven percent of the sample was male, and 32% had moderate or severe OSA (AHI, ≥15). Multivariable adjusted analysis showed significant associations between higher AHI with lower high-density lipoprotein cholesterol and higher diastolic blood pressure and neutrophil counts. Significant interactions with demographic factors were observed. Stronger associations were shown between AHI and higher total WBC count (Pint = 0.006) and glucose concentrations (Pint = 0.006) in younger (<65 yr) than in older individuals, higher triglyceride concentrations in men than in women (Pint = 0.006), and higher total WBC (Pint = 0.07) and monocyte counts (Pint = 0.03) in African American individuals than in other racial groups.

CONCLUSIONS

In a multiethnic cohort, we found increased levels of cardiovascular risk factors in association with OSA, including elevated neutrophil counts, a marker of inflammation. Furthermore, several associations were stronger in men, younger individuals, and African American individuals, highlighting pathways for CVD risk that may explain heterogeneity in the associations between CVD and OSA across population groups.

Association between severity of obstructive sleep apnea and glycated hemoglobin level in Japanese individuals with and without diabetes

Aim of this study was to examine the association between the severity of obstructive sleep apnea (OSA) and dysglycemia in Japanese individuals with and without type 2 diabetes (T2DM). We enrolled 115 individuals diagnosed with OSA with an apnea hypopnea-index (AHI) ≥ 20 in whom continuous positive airway pressure (CPAP) therapy was introduced (N = 115, 44 with T2DM, age 62 ± 11 years, BMI 27.0 ± 4.4 kg/m² and AHI median 36.1; interquartile range 27.2-48.1). During admission, the severity of OSA was evaluated by polysomnography, and its association with glycated hemoglobin (HbA1c) level was examined. Continuous glucose monitoring (CGM) was also conducted during the admission in 94 individuals. Apnea-hypopnea index (AHI), non-rapid eye movement (REM) AHI, minimum peripheral capillary oxygen saturation (SpO₂) and percentage of sleep time (%TST) with SpO₂ < 90% were significantly associated with HbA1c level in total and non-diabetic individuals (all p < 0.05) but not in those with T2DM, the majority of whom were treated with anti-diabetic medications. The associations of the non-REM AHI and %TST with SpO₂ < 90% with HbA1c level remained significant after adjustment for age, sex and BMI in non-diabetic and T2DM subjects treated with dietary therapy only. Mean glucose level, but not SD or coefficient of variation of glucose, assessed by CGM was significantly associated with AHI and non-REM AHI in non-diabetic subjects after adjustment for age, sex and BMI. In conclusion, the severity of OSA was associated with increased HbA1c level independently of BMI in Japanese individuals, especially in those without diabetes.

BMI 35 kg/m2 does not fit everyone: a modified STOP-Bang questionnaire for sleep apnea screening in the Chinese population

PURPOSE

The STOP-Bang questionnaire is the most widely used to detect surgical patients at high risk of obstructive sleep apnea (OSA). However, the body mass index (BMI) cutoff value in the original STOP-Bang questionnaire is 35 kg/m²; the BMI in the Chinese population is lower than that. We aimed to establish a more appropriate BMI cutoff value in the STOP-Bang questionnaire for Chinese patients.

METHODS

A total of 790 consecutive patients scheduled to undergo surgery at our hospital were included in this prospective study. All patients were asked to complete the STOP-Bang questionnaire and undergo a 7-h overnight polysomnography (PSG). The ability of STOP-Bang questionnaire to detect moderate to severe OSA (AHI ≥ 15 events/h) was assessed.

RESULTS

When the BMI cutoff value was set at 28 kg/m², the questionnaire had the highest Youden index, although no significant differences were found in the sensitivity of the test compared with the original BMI cutoff in total and in male patients. In females, changing the BMI cutoff value from 35 to 28 kg/m² resulted in the sensitivity of the test significantly increasing from 79.2% (74.9-83.5) to 89.3% (84.4-94.1), while the decrease in specificity was minor (from 43.6% [41.2-46.0] to 38.2% [36.1-40.3]), and the Youden index was highest (0.27) at this cutoff value. When the STOP-Bang questionnaire score was 4, the highest Youden index was obtained.

CONCLUSIONS

We recommend using a BMI cutoff value (28 kg/m²), and a STOP-Bang score ≥ 4 allows the anesthetist to identify patients with high risk of OSA.

Obstructive sleep apnea and objective short sleep duration are independently associated with the risk of serum vitamin D deficiency

BACKGROUND

Studies demonstrate an association between vitamin D (25(OH)D) deficiency and sleep disturbances, such as obstructive sleep apnea (OSA) and short sleep duration. However, to date, no studies have concurrently and objectively evaluated the effect of these factors on 25(OH)D.

OBJECTIVES

To evaluate whether OSA and objective short sleep duration are independently associated with reduced 25(OH)D in an adult population sample.

METHODS

A cross-sectional study included 657 individuals from the city of Sao Paulo, Brazil, as part of the ERA project. Participants fulfilled questionnaires and underwent clinical evaluation, polysomnography and blood sample collection for 25(OH)D quantification. OSA was classified into three categories (mild, moderate and severe). The risk of 25(OH)D deficiency was considered as levels<30 ng/mL. Short sleep duration was defined as total sleep time<6 hours.

RESULTS

The risk of 25(OH)D deficiency was observed in 59.5% of the sample, affecting more individuals of the female gender, obese, with African American ethnicity, and those that were smokers, sedentary and presented hypertension and diabetes. In the final logistic model adjusted for age, gender, ethnicity, obesity, smoking, hypertension, diabetes, sedentary lifestyle, seasonality and creatinine serum levels, both OSA and short sleep duration showed significant independent associations with the risk of 25(OH)D deficiency (moderate OSA: OR for 25(OH)D<30 = 2.21, 95% CI: 1.35-3.64, p<0.01; severe OSA: OR for 25(OH)D<30 = 1.78, 95% CI: 1.06-3.00, p = 0.03; short sleep duration: OR for 25(OH)D<30 = 1.61, 95% CI: 1.15-2.26, p = 0.01). After a subgroup analysis, similar results were observed only in participants ≥50 years.

CONCLUSION

OSA and short sleep duration are independently associated with the risk of 25(OH)D deficiency in an adult population. Age-related changes in vitamin D metabolism and the frequency of sleep disorders may be involved in these associations. Future studies exploring whether 25(OH)D levels may modulate OSA and sleep curtailment-related outcomes are needed.

Tailored approach to sleep health education (TASHE): study protocol for a web-based randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) is a sleep disorder that disproportionately affects African Americans (hereafter referred to as blacks). Moreover, blacks may underutilize sleep services including overnight polysomnography. Thus, OSA among blacks may go undiagnosed and untreated, which has significant health consequences, including hypertension, diabetes, cognitive impairment, and daytime sleepiness.

DESIGN AND METHODS

This two-arm randomized controlled trial will assign 200 participants to a culturally and linguistically tailored web-based sleep educational platform. The website will be developed to ensure that the content is user friendly and that it is readable and acceptable by the target community. Participants will receive login information to a password-protected website and will have access to the website for 2 months. Study assessments will be collected at baseline, 2 months (post-enrollment) and at 6 months (follow-up). We will use qualitative and quantitative methods to develop tailored materials and to ascertain whether tailored materials will increase OSA knowledge and OSA health literacy by comparing blacks exposed to tailored materials versus those exposed to standard sleep health literature. We hypothesize that exposure to tailored OSA information will improve OSA health literacy.

DISCUSSION

Few studies have investigated the racial/ethnic disparities in relation to OSA screening and treatment comparing blacks and whites. Moreover, we know of no interventions designed to increase OSA knowledge and health literacy among blacks. Use of the Internet to disseminate health information is growing in this population. Thus, the Internet may be an effective means to increase OSA health literacy, thereby potentially increasing utilization of sleep-related services in this population.

TRIAL REGISTRATION

The study is registered at clinicaltrials.gov, reference number NCT02507089 . Registered on 21 July 2015.

Sleep duration, daytime napping, markers of obstructive sleep apnea and stroke in a population of southern China

Sleep habits are associated with stroke in western populations, but this relation has been rarely investigated in China. Moreover, the differences among stroke subtypes remain unclear. This study aimed to explore the associations of total stroke, including ischemic and hemorrhagic type, with sleep habits of a population in southern China. We performed a case-control study in patients admitted to the hospital with first stroke and community control subjects. A total of 333 patients (n = 223, 67.0%, with ischemic stroke; n = 110, 23.0%, with hemorrhagic stroke) and 547 controls were enrolled in the study. Participants completed a structured questionnaire to identify sleep habits and other stroke risk factors. Least absolute shrinkage and selection operator (Lasso) and multiple logistic regression were performed to identify risk factors of disease. Incidence of stroke, and its subtypes, was significantly associated with snorting/gasping, snoring, sleep duration, and daytime napping. Snorting/gasping was identified as an important risk factor in the Lasso logistic regression model (Lasso' β = 0.84), and the result was proven to be robust. This study showed the association between stroke and sleep habits in the southern Chinese population and might help in better detecting important sleep-related factors for stroke risk.

Comparison of the Incidences of Obstructive Sleep Apnea-Hypopnea Syndrome in African-Americans versus Caucasian-Americans

OBJECTIVE: To determine the relative incidence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in African-Americans compared to a cohort of Caucasian-Americans.

STUDY DESIGN AND SETTING: A prospective study of 2 groups of subjects (287 African-Americans and 236 Caucasian-Americans) to evaluate OSAHS severity based on subjective symptoms and anatomic findings. Subjects were from a public health and fitness fair attended by approximately 80,000 people where attendees were invited for an ENT screening.

RESULTS: Using OSAHS scores based on subjective symptoms and anatomic findings, the African-American group had a significantly higher incidence of “probable” OSAHS. In addition to symptoms of OSAHS, the questionnaire ascertained that African-American bed partners are more likely to accept loud snoring as compared to Caucasian-American bed partners.

CONCLUSIONS: OSAHS may be more common in African-Americans, but African-American bed partners are more likely to accept snoring. The medical community should strive to increase awareness and education about OSAHS in the African-American community.

A community-oriented framework to increase screening and treatment of obstructive sleep apnea among blacks

OBJECTIVE

Obstructive sleep apnea (OSA) is a leading sleep disorder that is disproportionately more prevalent in minority populations and is a major risk factor for cardiovascular disease (CVD) morbidity and mortality. OSA is associated with many chronic conditions including hypertension, diabetes, and obesity, all of which are disproportionately more prevalent among blacks (ie, peoples of African American, Caribbean, or African descent).

METHODS

This article reviews studies conducted in the United States (US) that investigated sleep screenings and adherence to treatment for OSA among blacks. In addition, guidelines are provided for implementing a practical framework to increase OSA screening and management among blacks.

RESULTS

Several studies have documented racial/ethnic disparities in adherence to treatment for OSA. However, despite its public health significance, there is a paucity of studies addressing these disparities. Further, there is a lack of health programs and policies to increase screening and treatment of OSA among blacks and other minority populations. A practical framework to increase the number of blacks who are screened for OSA and treated appropriately is warranted. Such a framework is timely and major importance, as early identification of OSA in this high-risk population could potentially lead to early treatment and prevention of CVD, thereby reducing racial and ethnic disparities in sleep-related CVD morbidity and mortality.

Racial disparity in adherence to positive airway pressure among US veterans

PURPOSE

Despite advances in continuous positive airway pressure (CPAP) technology, compliance with CPAP therapy remains suboptimal. Studies conducted since the advent of objective CPAP recording have noted that African Americans (AA) may use CPAP less than Whites. We sought to confirm this finding among a large sample of veterans and examine effect modifiers of the differential usage.

METHODS

A retrospective cohort of 233 AA and 1939 White Veterans Administration (VA) patients who had a sleep study between January 2003 and October 2006 and received CPAP therapy by the end of 2007. CPAP compliance was summarized at 2 weeks and 6 months post CPAP receipt.

RESULTS

AAs were significantly less adherent than Whites even when controlling for age, gender, marital status, median household income for zip code, BMI, comorbidities, and obstructive sleep apnea (OSA) severity. AAs with severe OSA were 3 times more likely to use CPAP than AAs with mild/moderate OSA (p ≤ 0.001); a much smaller but still statistically significant difference was seen for Whites.

CONCLUSIONS

CPAP compliance is considerably lower in AAs than in Whites, though severity of OSA modifies this association. These findings are not readily explained by differences in demographics or comorbidity.

Obstructive Sleep Apnea: Comparison of Syndrome Severity and Risk Factors for Adult Jewish and Arab Males in Northern Israel

Background: Obstructive sleep apnea (OSA) is a common health problem with an estimated prevalence of 4% among men, many of whom are undiagnosed and untreated.

OBJECTIVES

To compare demographic characteristics, health profiles, risk factors, and disease severity in Arab and Jewish men with OSA syndrome.

METHODS

In this cross-sectional study we retrospectively analyzed clinical data from the medical files of men ≥ 22 years old who were referred to the Rambam Medical Center sleep clinic during the period 2001-2009 with a suspected diagnosis of OSA. OSA severity was measured using the apnea-hypopnea index (AHI). Categorical variables were compared using the chi-square test. Relations between OSA severity and a set of independent risk factors were assessed by linear regression analysis.

RESULTS

A total of 207 men were included (39 Arabs, 19%; 168 Jews, 81%). Arab participants were younger than their Jewish counterparts (45.5 ± 8.9 years vs. 49.8 ± 11.8, P = 0.04) and their body mass index (BMI) was higher (3.1 ± 5.1 vs. 30.0 ± 4.4, P = 0.001). OSA severity (AHI score) was higher among Arab men, with low, medium and high severity scores seen in 10%, 33% and 56% of Arab men vs. 35%, 29% and 37% of Jewish men, respectively [T(198) = 2.39, P = 0.02]. Mean blood oxygen saturation was comparable.

CONCLUSIONS

Arab men presenting for evaluation of sleep apnea harbored more severe OSA symptoms, were younger, and had higher BMI compared to Jewish men. Since OSA syndrome evolves for several years until it becomes severe, these findings suggest that Arab men seek medical assistance later than Jewish men with OSA.

The utility of three screening questionnaires for obstructive sleep apnea in a sleep clinic setting

PURPOSE

The aim of this study was to determine the diagnostic value of three screening questionnaires in identifying Korean patients at high risk for obstructive sleep apnea (OSA) in a sleep clinic setting in Korea.

MATERIALS AND METHODS

Data were collected from 592 adult patients with suspected OSA who visited a sleep center. All patients completed the Sleep Apnea of Sleep Disorder Questionnaire (SA-SDQ), the Berlin questionnaire, and the STOP-Bang questionnaire. Estimated OSA risk was compared to a diagnosis of OSA. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each questionnaire.

RESULTS

The prevalence of OSA was 83.6% using an apnea-hypopnea index (AHI) ≥5/h and 58.4% for an AHI ≥15/h. The STOP-Bang questionnaire had a high sensitivity (97% for AHI ≥5/h, 98% for AHI ≥15/h), but the specificity was low (19% and 11%, respectively). In contrast, the sensitivity of the SA-SDQ was not high enough (68% for AHI ≥5/h, 74% for AHI ≥15/h) to be useful in a clinical setting, whereas the specificity was relatively good (66% and 61%, respectively). The sensitivity and specificity values of the Berlin questionnaire fell between those of the STOP-Bang questionnaire and the SA-SDQ.

CONCLUSION

The STOP-Bang questionnaire may be useful for screening OSA in a sleep clinic setting, but its specificity is lower than the acceptable level for this purpose. A new screening questionnaire with a high sensitivity and acceptable specificity is therefore needed in a sleep clinic setting.

[Presumption of sleep apnea in a black African hypertensive population: Importance of the Epworth sleepiness scale in the diagnostic approach]

INTRODUCTION

Sleep apnea syndrome (SAS) is very little described in the hypertensive black African.

PURPOSE

To screen sleep apnea syndrome using the rating scale of Epworth daytime sleepiness, and to investigate the determinant factors and to infer therapeutic consequences.

METHOD

This is a retrospective and prospective study with descriptive and analytical purpose that focused on 200 hypertensive outpatients of the Cardiology Institute of Abidjan. The primary endpoint studied was the SAS. The diagnostic approach of SAS was performed using the rating scale of Epworth daytime sleepiness.

RESULTS

The prevalence of sleep apnea was 45%. The average age of sleep apnea carriers was 56.1 years, with a male predominance (60%). The determinant factors of sleep apnea syndrome were male gender (60% versus 40%, P=0.021), obesity (77.8% versus 62.7%, P<0.0001), diabetes (26.7% versus 15.5%, P=0.5) and dyslipidemia (54.4% versus 27.3%, P=0.0009). Life in urban areas, occupation and smoking were not correlated with SAS in our series. The control of hypertension was better in non-apneic patients compared to apneic patients (63.6% versus 38.9%, P=0.04). The visceral impact of hypertension in apneic patients was highly significant (77.8% versus 41.7%, P=0.014). Therapeutically, it was noted the preferential prescription of combination therapy in apneic patients compared to non-apneic patients (82.3% versus 74.4%).

Continuous positive airway pressure treatment for obstructive sleep apnoea: Maori, Pacific and New Zealand European experiences

INTRODUCTION

Continuous positive airway pressure (CPAP) is an effective treatment of obstructive sleep apnoea (OSA), but can be limited by poor adherence. In New Zealand (NZ), ethnicity has been shown to be a predictor of CPAP adherence. This study aimed to explore Maori , Pacific and NZ European patients' experience of CPAP treatment.

METHODS

Patients identifying as Maori , Pacific, or NZ European ethnicity referred for CPAP treatment for OSA attended separate, 1.5-hour group discussions facilitated by a health care worker of the same ethnic group, using an interview template. Thematic analysis was applied to the discussion transcripts independently by two investigators, following published guidelines.

FINDINGS

Five Maori , five Pacific, and eight NZ Europeans participated (mean age 47, range 30-71 years, mean ± standard deviation CPAP adherence 6.32 ± 1.25 hours/night). Patients in all three groups reported that they had little knowledge of OSA or CPAP prior to treatment initiation. All groups identified barriers to treatment (both at the CPAP initiation phase and long term), reported feelings of being 'overwhelmed' with information during the initial CPAP education session, and discussed the importance of successful role models. Family and friends were generally reported as being supportive of CPAP therapy.

CONCLUSION

The three groups all reported similar initial CPAP experiences, highlighting access barriers to publicly funded assessment and treatment pathways, and sleep health knowledge as key issues. Educational resources to improve access, enable self-management, and increase community awareness of OSA would help overcome some of the issues identified in this study.

Self-reported snoring and metabolic syndrome: the Korean Multi-Rural Communities Cohort Study

PURPOSE

We investigated the association between self-reported snoring and metabolic syndrome (MetS) and its components among a community-dwelling Korean population.

METHODS

A total of 7,038 subjects participated in the Korean Multi-Rural Communities Cohort Study between January 2005 and February 2010 and were included in the analysis. Frequency of snoring was classified into never, rarely (<1 day/week), occasionally (1-3 days/week), and habitually (≥4 days/week).

RESULTS

In the fully adjusted model, compared to non-snorers, the odds ratio (OR) for MetS of snorers was significantly higher in subjects with rare snoring (OR, 1.42; 95% confidence interval (CI), 1.23-1.64), occasional snoring (OR, 1.79; 95% CI, 1.55-2.07), and habitual snoring (OR, 2.03; 95% CI, 1.77-2.33) than those who did not snore. The ORs for abdominal obesity were significantly higher in rare snoring subjects (OR, 1.51; 95% CI, 1.30-1.75), occasional snoring (OR, 1.71; 95% CI, 1.47-1.98), and habitual snoring (OR, 2.07; 95% CI, 1.80-2.38) than in non-snorers after adjusting for covariates.

CONCLUSIONS

Snoring was significantly and linearly associated with MetS, and this association was consistently present in both sexes. Positive and graded associations were observed between snoring frequency and MetS components including high blood pressure, elevated fasting glucose levels, and abdominal obesity, independent of conventional risk factors and other MetS components.

Prevalence of signs and symptoms suggestive of obstructive sleep apnea syndrome in Guangxi, China

BACKGROUND

The prevalence, profiles, and potential risk factors of snoring and obstructive sleep apnea-hypopnea syndrome (OSAHS) in China are largely unknown.

OBJECTIVES

This study aims to investigate the prevalence, profiles, and potential risk factors for snoring and OSAHS in Guangxi, China, and the association between OSAHS and ethnicity.

METHODS

Urban and rural population-based cluster samples were randomly selected in each of eight counties/cities. All residents aged 14 years or older in the selected clusters were interviewed using a standardized questionnaire. A subject was considered to have clinically diagnosed OSAHS if snoring was loud and habitual, breathing pauses were observed, and the subject experienced excessive daytime sleepiness.

RESULTS

Among 12,742 sampled subjects, 10,819 completed the questionnaire (response rate = 84.9%). The overall OSAHS prevalence was 4.1% (men, 5.7% (5.1-6.3%); women, 2.4% (2.0-2.9%); Zhuang people, 3.2% (2.8-3.7%); Han people 6.0% (5.2-6.8%).The overall rate of habitual snoring was 11.5 % (men, 17.1% (16.1-18.1%); women, 5.6% (5.0-6.2%)). Univariate analysis showed that the OSAHS prevalence was significantly higher among the following groups: urban residents, elderly individuals, smokers, drinkers, those with higher body mass indexes (BMI), those with more years of schooling, those with nasal problems, those whose parents are Han, and those who usually sleep in prone position. However, multiple logistic regression analysis revealed that only urban residency, age, smoking status, drinking status, and BMI were the risk factors for OSAHS.

CONCLUSIONS

OSAHS is prevalent in individuals aged 14 years or older in Guangxi, China. Han and Zhuang people differ significantly in their obstructive sleep apnea (OSA) prevalence, but this difference is explained by the combination of classic OSA risk factors.

The association of age, insomnia, and self-efficacy with continuous positive airway pressure adherence in black, white, and Hispanic U.S. Veterans

STUDY OBJECTIVES

Studies of continuous positive airway pressure (CPAP) adherence in multi-ethnic samples are lacking. This study explores previously described factors associated with therapeutic CPAP use in South Florida veterans with obstructive sleep apnea-hypopnea syndrome (OSAHS).

METHODS

We performed a retrospective, cross-sectional analysis of CPAP adherence comparing white, black, and Hispanic veterans returning to the Miami VA sleep clinic over a 4-month period. Participants had CPAP use download and completed questionnaires on demographics, sleepiness, insomnia, and social cognitive measures related to adherence. Linear regression modeling was used to explore the impact of measured variables and potential interactions with race-ethnicity on mean daily CPAP use.

RESULTS

Participants (N = 248) were 94% male with mean age of 59 ± 11 years and included 95 blacks (38%), 91 whites (37%), and 62 Hispanic (25%) veterans. Blacks had less mean daily CPAP use than whites (-1.6 h, p < 0.001) and Hispanics (-1.3 h, p < 0.01). Blacks reported worse sleep onset insomnia symptoms compared to whites. In the final multivariable regression model, black race-ethnicity (p < 0.01), insomnia symptoms (p < 0.001), and self-efficacy (p < 0.001) were significantly associated with mean daily CPAP use. In addition, the black race by age interaction term showed a trend towards significance (p = 0.10).

CONCLUSIONS

In agreement with recent studies, we found that mean daily CPAP use in blacks was 1 hour less than whites after adjusting for covariates. No CPAP adherence differences were noted between whites and Hispanics. Further investigations exploring sociocultural barriers to regular CPAP use in minority individuals with OSAHS are needed.

Validity and reliability of the Malay version of Sleep Apnea Quality of Life Index--preliminary results

BACKGROUND

The objective of this study was to determine the validity and reliability of the Malay translated Sleep Apnea Quality of Life Index (SAQLI) in patients with obstructive sleep apnea (OSA).

METHODS

In this cross sectional study, the Malay version of SAQLI was administered to 82 OSA patients seen at the OSA Clinic, Hospital Universiti Sains Malaysia prior to their treatment. Additionally, the patients were asked to complete the Malay version of Medical Outcomes Study Short Form (SF-36). Twenty-three patients completed the Malay version of SAQLI again after 1-2 weeks to assess its reliability.

RESULTS

Initial factor analysis of the 40-item Malay version of SAQLI resulted in four factors with eigenvalues >1. All items had factor loadings >0.5 but one of the factors was unstable with only two items. However, both items were maintained due to their high communalities and the analysis was repeated with a forced three factor solution. Variance accounted by the three factors was 78.17% with 9-18 items per factor. All items had primary loadings over 0.5 although the loadings were inconsistent with the proposed construct. The Cronbach's alpha values were very high for all domains, >0.90. The instrument was able to discriminate between patients with mild or moderate and severe OSA. The Malay version of SAQLI correlated positively with the SF-36. The intraclass correlation coefficients for all domains were >0.90.

CONCLUSIONS

In light of these preliminary observations, we concluded that the Malay version of SAQLI has a high degree of internal consistency and concurrent validity albeit demonstrating a slightly different construct than the original version. The responsiveness of the questionnaire to changes in health-related quality of life following OSA treatment is yet to be determined.

Determinants of continuous positive airway pressure adherence in a sleep clinic cohort of South Florida Hispanic veterans

PURPOSE

There are little existing data on continuous positive airway pressure (CPAP) adherence in US Hispanic veterans with obstructive sleep apnea (OSA). Our aim was to describe determinants of 1-month adherence in a sleep clinic cohort of South Florida Hispanic veterans.

METHODS

Hispanic veterans referred to the Miami VA sleep clinic were recruited and completed questionnaires about sleep apnea risk, sleep quality, insomnia symptoms, sleepiness, depression/anxiety, acculturation, personality traits, and cognitions about OSA and CPAP. Individuals at risk for OSA were scheduled for baseline polysomnography (PSG), followed by in-lab CPAP titration or a trial of auto-CPAP. Participants with OSA accepting CPAP therapy were asked to return after 7 and 30 days of treatment for adherence verification and to repeat questionnaires.

RESULTS

One hundred twenty-four participants (94 % men) were enrolled with 114 completing overnight PSG. Eighty-six out of 95 participants (91 %) with sleep apnea syndrome or moderate to severe OSA accepted CPAP treatment. Fifty-nine participants completed both follow-up visits with a mean CPAP use at 30 days of 3.6 ± 2.0 h. The only independent predictor of 7-day mean daily CPAP use was the baseline Insomnia Severity Index while the best predictor of 30-day mean daily CPAP use was the 7-day mean daily use.

CONCLUSIONS

Our study suggests that South Florida Hispanic veterans with OSA evaluated in a sleep clinic show poor CPAP adherence. Insomnia and poor early use predicted poor adherence overall. Larger prospective studies with other race-ethnic groups are needed to determine the role of ethnicity and race in CPAP adherence among US veterans with OSA.

Changes in facial appearance after maxillomandibular advancement for severe obstructive sleep apnoea hypopnoea syndrome in Chinese patients: a subjective and objective evaluation

This study evaluates the outcome and change in facial appearance after maxillomandibular advancement (MMA) in Chinese adults with severe obstructive sleep apnoea hypopnoea syndrome (OSAHS). Twelve patients underwent MMA with adjunctive procedures for severe OSAHS. All underwent physical examination, Epworth Sleepiness Scale evaluation, cephalometry, polysomnography, and facial photographic assessment before and 6 months after MMA. The aesthetic plane (relationship of nose, lips, and chin) was used to judge soft tissue facial profile change after MMA. Postoperative cephalometric data were compared with normal occlusive standards and aesthetic norms. Pre- and postoperative aesthetic appearance was evaluated by 100 lay people using a 10-point visual analogue scale. The maxillomandibular complex (MMC) was advanced 5-10 mm (mean 7.4 mm). The success rate was 83%. All patients were satisfied with the functional and aesthetic results. Postoperative SNA, SNB, and posterior airway space increased and mandibular plane-to-hyoid distance decreased significantly in all patients. The lower lip was closer to EP than the preoperative and normal occlusive standard. In 11 of 12 patients, the lay aesthetic scores were significantly higher postoperatively. MMA is effective for Chinese adults with severe OSAHS. In most patients, facial appearance was more attractive after MMC advancement of 5-10 mm.

Relationships of decreased lung function with metabolic syndrome and obstructive sleep apnea in Japanese males

OBJECTIVE

Decreased lung function as assessed by forced vital capacity (FVC) and forced expiratory volume in one second (FEV(1)) is shown to be associated with cardiovascular morbidity and mortality. Although the underlying mechanisms for this association remain unknown, metabolic syndrome and obstructive sleep apnea (OSA) may have a role. We analyzed the relationships between metabolic syndrome and OSA in a cross-sectional health survey of middle-aged male employees.

METHODS

In this secondary analysis, we re-analyzed the relationships of lung function determined by spirometry with metabolic syndrome and OSA based on the respiratory disturbance index (RDI) with a type 3 portable monitor.

RESULTS

We analyzed 273 subjects. Independent of age, body mass index (BMI) and smoking, quartiles for lower FVC and FEV(1) were associated with a higher risk of metabolic syndrome compared with quartiles for the highest FVC and FEV(1), respectively. A similar trend was observed regarding the risk associated with waist circumference, and in FVC cases, dyslipidemia. The risk of hyperglycemia was significantly higher in quartiles for the second lowest FVC and FEV(1) than in quartiles for the highest FVC and FEV(1), respectively. A significant trend for an increase in RDI was observed in accordance with quartiles for lower FVC, but not FEV(1).

CONCLUSION

There was a significant relationship between lung function impairment and metabolic syndrome through mainly abdominal obesity, partially through hyperglycemia, and also through dyslipidemia, but only with respect to restrictive lung function. Restrictive lung function was also related to OSA. This epidemiologic evidence may indicate underlying mechanisms between decreased lung function and cardiovascular risk.

Managing obstructive sleep apnoea and achieving equity: implications for health services

Sleep occupies a third of life, and poor sleep has wide-ranging consequences for health, safety, and well-being. Recent research suggests significant inequalities in sleep health between Māori and non-Māori adults in New Zealand including self-reported sleeping problems and obstructive sleep apnoea syndrome (OSAS). This paper will outline a series of studies that were designed to assess how many people were affected by OSAS in Aotearoa/New Zealand and specifically sought to prioritise the needs of Māori. It will discuss a number of issues related to the diagnosis and treatment of OSAS in New Zealand and present strategies for reducing inequalities in sleep health.

Gender and ethnic differences in prevalence of self-reported insomnia among patients with obstructive sleep apnea

BACKGROUND

Insomnia and obstructive sleep apnea (OSA) are the two most common sleep disorders. Studies have shown that complaints of insomnia are prevalent among sleep clinic patients evaluated for OSA. Less is known about the gender and ethnic variations in this association.

OBJECTIVES

This paper aims to study the influence of gender and ethnicity in the prevalence of insomnia in patients with OSA and explore the association between these two disorders with an emphasis on psychophysiologic insomnia.

METHODS AND MEASUREMENTS

We reviewed case files, including self-reported questionnaires and polysomnography studies of 300 OSA patients [apnea-hypopnea index (AHI) of >10] from three ethnic groups--Caucasian, Hispanic, and African American, 50 patients each, male and female, seen at a tertiary care county hospital adult sleep center. Self-reported insomnia was classified as sleep onset insomnia, sleep maintenance insomnia, or insomnia with early morning awakening. Psychophysiologic insomnia was documented if the patient reported two of the following five symptoms: racing thoughts when trying to sleep, increased muscle tension when trying to sleep, fear of being unable to sleep, fear of being unable to fall back to sleep after waking up, and lying in bed worrying. Fischer exact tests for each contingency table were run using SPSS.

RESULTS

Among OSA patients, women were older, had higher body mass index, and lower AHI at the time of diagnosis, compared to men. Insomnia was more prevalent among patients with OSA (84%) than the reported 30% among general adult population. Sleep onset insomnia was reported more frequently by women (62%) than men (53%) (p = 0.03). Similarly self-reported psychophysiologic insomnia also showed a female preponderance (53% vs. 45%, p = 0.03). Caucasian women had the highest rate of self-reported sleep maintenance insomnia (80%). Hispanic women are more likely to complain of symptoms suggestive of psychophysiologic insomnia (58%).

CONCLUSIONS

There is a higher prevalence of insomnia in OSA patients. Ethnicity and gender possibly exhibit a complex and significant influence on the reported subtype of insomnia. Further larger studies may help confirm, as well as clarify, mechanisms that underlie the ethnic and gender differences that we have noted.

Differences in craniofacial structures and obesity in Caucasian and Chinese patients with obstructive sleep apnea

STUDY OBJECTIVES

To explore differences in craniofacial structures and obesity between Caucasian and Chinese patients with obstructive sleep apnea (OSA).

DESIGN

Inter-ethnic comparison study.

SETTING

Two sleep disorder clinics in Australia and Hong Kong.

PATIENTS

150 patients with OSA (74 Caucasian, 76 Chinese).

INTERVENTIONS

Anthropometry, cephalometry, and polysomnography were performed and compared. Subgroup analyses after matching for: (1) body mass index (BMI); (2) OSA severity.

MEASUREMENTS AND RESULTS

The mean age and BMI were similar between the ethnic groups. Chinese patients had more severe OSA (AHI 35.3 vs 25.2 events/h, P = 0.005). They also had more craniofacial bony restriction, including a shorter cranial base (63.6 +/- 3.3 vs 77.5 +/- 6.7 mm, P < 0.001), maxilla (50.7 +/- 3.7 vs 58.8 +/- 4.3 mm, P < 0.001) and mandible length (65.4 +/- 4.2 vs 77.9 +/- 9.4 mm, P < 0.001). These findings remained after correction for differences in body height. Similar results were shown in the BMI-matched analysis (n = 66). When matched for OSA severity (n = 52), Chinese patients had more craniofacial bony restriction, but Caucasian patients were more overweight (BMI 30.7 vs 28.4 kg/m2, P = 0.03) and had a larger neck circumference (40.8 vs 39.1 cm, P = 0.004); however, the ratios of BMI to the mandible or maxilla size were similar.

CONCLUSIONS

Craniofacial factors and obesity contribute differentially to OSA in Caucasian and Chinese patients. For the same degree of OSA severity, Caucasians were more overweight, whereas Chinese exhibited more craniofacial bony restriction.

Epidemiology of adult obstructive sleep apnoea syndrome in India

There is a paucity of published Indian studies on the prevalence and risk factors of obstructive sleep apnoea (OSA) in adults. The limited published literature, however, does not suggest significant differences in the prevalence and risk factors for OSA and obstructive sleep apnoea syndrome (OSAS) as compared to western studies. Well designed studies are required from all parts of India. Patients should be screened carefully before referring them to costly investigations such as overnight polysomnography. With the background of increasing urbanization, fast growing economy and changes in lifestyle, India will have an epidemic of obesity. Therefore, future studies on the association of OSA and metabolic syndrome should carefully evaluate confounding effect of obesity on metabolic abnormalities in patients with OSA.

Efficacy of continuous positive airway pressure on arrhythmias in obstructive sleep apnea patients

The purpose of this study was to determine the relationship between obstructive sleep apnea (OSA) and cardiovascular disorders in a large Japanese population, and to assess the efficacy of continuous positive airway pressure (CPAP) in the treatment of OSA-associated arrhythmias. The study population comprised 1394 Japanese subjects (1086 men and 308 women) who were divided into four groups on the basis of polysomnography (PSG) analysis as follows: the no sleep apnea (N-SA) group (n = 44, apnea-hypopnea index [AHI] < 5), the mild OSA (Mi-OSA) group (n = 197, 5 < AHI < 15), the moderate OSA (Mo) group (n = 368, 15 < AHI < 30), and severe OSA (SOSA) group (n = 785, AHI < 30). The following baseline characteristics were significantly associated with OSA: age (P < 0.001), gender (P < 0.001), body mass index (P < 0.001), hypertension (P < 0.001), diabetes (P = 0.009), and hyperlipidemia (P = 0.013). In the OSA group, PSG revealed the predominance of paroxysmal atrial fibrillation (PAF) (P = 0.051), premature atrial complex short run (P < 0.005), premature ventricular complex (PVC, P = 0.004), sinus bradycardia (P = 0.036), and sinus pause (arrest >2 s, P < 0.001) during the PSG recording. A total of 316 patients from the group underwent CPAP titration and were then re-evaluated. Continuous positive airway pressure therapy significantly reduced the occurrences of PAF (P < 0.001), PVC (P = 0.016), sinus bradycardia (P = 0.001), and sinus pause (P = 0.004). The results of this study demonstrate a significant relationship between OSA and several cardiac disorders, and also demonstrate the efficacy of CPAP in preventing OSA-associated arrhythmias in a large population of Japanese patients.

Obstructive sleep apnoea correlates with C-reactive protein in obese Asian Indians

BACKGROUND

C-reactive protein (CRP), a marker of systemic inflammation, is an important predictor of future cardiovascular events. Whether the relationship of obstructive sleep apnoea (OSA) and CRP is independent of adiposity, needs to be investigated.

OBJECTIVE

To investigate the association of CRP levels with OSA in the obese and their comparison with lean subjects without OSA in Asian Indians residing in India.

METHODS AND RESULTS

One hundred and eight obese subjects (62 treatment naïve obese subjects with OSA [cases] and 46 obese subjects without OSA [obese controls]) and 26 lean control subjects without OSA were studied. The subjects were without any apparent inflammatory disease. Obese subjects were matched for body mass index (BMI) and percentage body fat (%BF). Assessment included anthropometry, lipid profile and high sensitivity CRP (hs-CRP) levels. Mean hs-CRP levels were significantly higher in cases [(3.6+/-2.0) mg/l than in obese controls (1.4+/-1.4) mg/l, p<0.001)] and in lean controls [(0.93+/-0.71) mg/l, p>0.05].

CONCLUSIONS

In this sample of Asian Indians, subjects with OSA had significantly higher CRP levels. These levels were directly proportional to the increase in severity of OSA and it was independent of adiposity. These observations have important implications for future cardiovascular risk in Asian Indians with OSA.

Glucose intolerance in Japanese patients with obstructive sleep apnea

OBJECTIVE

Obstructive sleep apnea syndrome (OSAS) often accompanies obesity and diabetes mellitus. This study was performed to investigate the prevalence of glucose intolerance and to determine independent predictors for insulin resistance in patients with OSAS.

METHODS

A cross-sectional study of 679 OSAS patients with an apnea-hypopnea index (AHI)>or=5/h and 73 controls subjects (AHI<5/h) was done in a tertiary university-based medical center. They were assessed by nocturnal polysomnography and underwent an oral glucose tolerance test.

RESULTS

The prevalence of diabetes mellitus in OSAS patients was higher than that of the control group (25.9% vs. 8.2%, p<0.001) and 424 patients (62.4%) received a new diagnosis of impaired glucose tolerance or diabetes mellitus. The very severe OSAS group (AHI >or=45/h) had significantly higher homeostasis model assessment of insulin resistance (HOMA-IR) and HOMA beta-cell function than the other OSAS groups (AHI<45/h) and the control group. In a logistic regression model adjusting for potential confounders: age, AHI, minimum SpO(2) and body mass index (BMI), only BMI was associated with insulin resistance (HOMA-IR>3) (odds ratio: 1.272, 95% confidence interval 1.206-1.343, p<0.0001).

CONCLUSION

Glucose intolerance was more common in patients with OSAS. Insulin resistance was associated not with AHI but rather with BMI.

Race and financial strain are independent correlates of sleep in midlife women: the SWAN sleep study

STUDY OBJECTIVES

To examine racial differences in sleep in a large cohort of midlife women and to evaluate whether indices of socioeconomic status (SES) are associated with racial differences in sleep.

DESIGN

Cross-sectional study.

SETTING

Participants' homes.

PARTICIPANTS

Caucasian (n=171), African American (n=138) and Chinese women (n=59).

INTERVENTIONS

None.

MEASUREMENTS

Sleep quality was assessed with the Pittsburgh Sleep Quality Index. Polysomnographically assessed sleep duration, continuity, architecture, and NREM electroencephalograhic (EEG) power were calculated over multiple nights. Sleep disordered breathing and periodic leg movements were measured on a separate night. Linear regression analysis was used to model the independent and synergistic effects of race and SES on sleep after adjusting for other factors that impact sleep in midlife women. Indices of SES were self-reported educational attainment and financial strain.

RESULTS

Sleep was worse in African American women than Caucasian participants as measured by self-report, visual sleep stage scoring, and NREM EEG power. Slow wave sleep differences were also observed between Chinese and Caucasian participants. Racial differences persisted after adjustment for indices of SES. Although educational attainment was unrelated to sleep, financial strain was associated with decreased sleep quality and lower sleep efficiency. Financial strain-by-race interactions were not statistically significant, suggesting that financial strain has additive effects on sleep, independent of race.

CONCLUSIONS

Independent relationships between race and financial strain with sleep were observed despite statistical adjustment for other factors that might account for these relationships. Results do not suggest that assessed indices of SES moderate the race-sleep relationship, perhaps due to too few women of low SES in the study.

Association study of serotonin transporter gene polymorphisms with obstructive sleep apnea syndrome in Chinese Han population

BACKGROUND

Since the serotonin (5-HT) is associated with circadian rhythm and breathing regulation, the serotonin transporter (5-HTT), which plays an important role in serotoninergic transmission, might be a strong candidate gene in the pathogenesis of obstructive sleep apnea syndrome (OSAS).

OBJECTIVE

To investigate the association of 5-HTT gene polymorphisms with OSAS and clinical characteristics.

METHODS

We genotyped the 5-HTT gene linked polymorphic region (5-HTTLPR) and a variable number of tandem repeats at intron 2 (STin2.VNTR) in 254 OSAS patients and 338 healthy controls in Chinese Han population.

RESULTS

In total sample, the 10-repeat allele of STin2.VNTR was significantly associated with OSAS (P = 0.007, OR = 1.72, 95% CI = 1.15-2.58), but no association was found in 5-HTTLPR. In male subjects, both polymorphisms showed significant association with OSAS (Allele L: P = 0.005, OR = 1.44, 95% CI = 1.11 to 1.87; Allele 10: P = 0.002, OR= 1.94, 95% CI = 1.26 to 3.00). Two haplotypes, S-12 and L-10, constructed by the above polymorphisms also revealed significant associations with OSAS (global P-values were 0.020 for total sample and 0.0006 for male subjects, respectively). Male patients carrying the haplotype S-12 showed a significantly lower apnea / hypopnea index (AHI), depressive factor, plasma 5-HT level and 5-hydroxyindolacetic acid (5-HIAA) levels, but higher episodic memory, when compared with non-S-12 carriers (P < 0.05). However, no significant differences were found in excessive daytime sleepiness or other psychological function across haplotype carriers (P > 0.05).

CONCLUSIONS

These findings support that 5-HTT gene may be involved in susceptibility to OSAS, especially with sex-dependent effect.

Evaluation of sleep apnea in a sample of black patients

OBJECTIVES

Few minority patients with sleep apnea have been evaluated or treated. This study ascertained adherence rate to referrals for sleep apnea evaluation by primary care physicians in a community-based sample of black patients; it also examined baseline characteristics likely to influence adherence rates.

METHODS

A retrospective chart audit was conducted at a hospital-based sleep clinic. Scrutiny was limited to male and female patients between the ages of 20 and 80 years. Data obtained for this analysis included baseline characteristics from a detailed sleep history and/or screening questionnaires and polysomnographic parameters.

RESULTS

Of the 421 patients referred by their private care physicians, 38% (n=160) adhered to the recommendation for a sleep consultation, but all who showed up for their appointment underwent polysomnographic studies. Logistic regression analyses showed that obesity and daytime sleepiness were the most important factors predicting adherence, with multivariate-adjusted odds ratios of 2.69 [95% CI: 1.54-4.71, p < 0.001] and 6.98 [95% CI: 3.86-12.64, p < 0.001], respectively. Of the patients who underwent a polysomnographic sleep evaluation, 91% received a sleep apnea diagnosis and were treated.

CONCLUSIONS

Black patients may be underutilizing available sleep services, but direct comparisons with other ethnic groups could not be made because of insufficient archival data. While the present study does not identify specific barriers to accessing services for sleep problems, it indicates that blacks who are obese and/or are experiencing daytime sleepiness are likely to adhere to recommendations of their physician. Targeted culturally congruent educational interventions to increase awareness of sleep apnea in black communities might help to increase adherence rate.

Symptoms of obstructive sleep apnea in a Caribbean sample

Obstructive sleep apnea (OSA) is a prevalent sleep disorder that disproportionately affects blacks. While clinical and epidemiologic data indicate intraethnic differences in several medical diseases, little is known about whether OSA symptoms differ within the black ethnic group. We estimated the rate of OSA symptoms in a community-based sample of Caribbean-born black men and women. We also ascertained which sociodemographic and/or medical factors were associated with OSA risk. A total of 554 patients (mean age = 48.17 +/- 16.75 years) participated in the study; 55% were women. Data were collected in four primary-care clinics in Brooklyn, NY. A health educator explained the purpose of the study to interested patients and assisted consenting participants in completing questionnaires, which required 15 min to complete. Participants reporting habitual snoring, excessive daytime sleepiness, and sleep fragmentation were considered at high OSA risk. The rate of OSA symptoms was: snoring (45%), excessive daytime sleepiness (33%), and difficulty maintaining sleep (34%). Many reported falling asleep while watching television (47%) or while driving (14%). Based on logistic regression analysis, a history of heart disease was the most important predictor of the likelihood of expressing OSA symptoms, with a corresponding multivariate-adjusted odds ratio of 11 (95% confidence interval = 3.03-40.63). Findings suggest the need to investigate whether Caribbean-born blacks are at greater risk for developing OSA than African Americans and whites. Caribbean-born blacks with a history of heart disease should be a prime target for interventions that promote adequate screening and timely OSA diagnosis.

Predicting continuous positive airway pressure from a modified split-night protocol in moderate to severe obstructive sleep apnea-hypopnea syndrome

BACKGROUND

Most split-night sleep (SNS) studies have enrolled Caucasian patients with moderate-to-severe obstructive sleep apnea-hypopnea syndrome (OSAHS), with different apnea-hypopnea index (AHI) criteria for diagnosis and successful CPAP titration from the standard full-night study (FNS). This study aimed to describe a shortened diagnostic SNS in the Taiwanese population using diagnostic and CPAP therapeutic criteria identical to the standard FNS, and to generate a predictive equation for effective CPAP (Peff) titration.

METHODS

A total of 418 patients with moderate-to-severe OSAHS were enrolled in this study. The duration of the diagnostic SNS was shortened to approximately 1-2 hours. The diagnostic accuracy and the success rate of CPAP titration in SNS were evaluated and a statistical model for Peff was built. The accuracy of the predictive equation was validated in another 127 patients.

RESULTS

Eighty-nine percent of patients with moderate-to-severe OSAHS diagnosed in the preceding FNS yielded the same grade of OSAHS in SNS. These reproducible patients were more severe, with 88% attaining successful CPAP titration in SNS. The predictive Peff=1.98+0.184xBMI+0.01xAHISNS +0.016xDISNS (R2=0.28, p<0.0001) where BMI was the body mass index and DI the desaturation index. The | predictive Peff- Peff | was within 2 cm H(2)O in 84% of the study group and 73% of the validation group.

CONCLUSION

The modified split-night protocol and the predictive equation for CPAP can be useful in Taiwanese patients with moderate-to-severe OSAHS. Our findings may shorten the waiting time for polysomnography.

[The association between polymorphism of the serotonin 2A, 2C receptor genes and obstructive sleep apnea-hypopnea syndrome in Han population]

OBJECTIVE

To investigate the association between polymorphisms of the serotonin 2A, 2C receptor genes and obstructive sleep apnea-hypopnea syndrome (OSAHS), and therefore to explore the genotypes related to OSAHS.

METHODS

The T102C and A1438G polymorphisms of the serotonin 2A receptor genes and the G796C polymorphisms of the serotonin 2C receptor genes were identified by polymerase chain reaction-restricted fragment length polymorphism assay in 119 unrelated subjects (including 65 OSAHS patients and 54 normal controls) of "Han" population of China. The genotype distribution and the allele frequencies of the polymorphisms were compared between the OSAHS group and the control group. The effects of polymorphisms in the OSAHS group on parameters of polysomnography and indexes correlated with obesity were analyzed.

RESULTS

There was no significant difference in genotype distribution and allele frequencies of the T102C polymorphisms of the serotonin 2A receptor genes between the two groups; the frequencies of TT/TC/CC genotype and T/C allele were 27.7% (18/65), 46.2% (30/65), 26.1% (17/65), 50.8% (66/130) and 49.2% (64/130), respectively in the OSAHS group; but were 27.8% (15/54), 51.8% (28/54), 20.4% (11/54), 53.7% (58/108) and 46.3% (50/108), respectively in the control group (chi(2) = 0.616 and 0.203, respectively, P > 0.05). The G796C polymorphisms of the serotonin 2C receptor genes were as follows: the frequencies of male's G/C allele, female's GG/GC genotype and G/C allele were 88.9% (48/54), 11.1% (6/54), 63.6% (7/11), 36.4% (4/11), 81.8% (18/22) and 18.2% (4/22), respectively in the OSAHS group; but were 90.5% (38/42), 9.5% (4/42), 66.7% (8/12), 33.3% (4/12), 83.3% (20/24) and 16.7% (4/24), respectively in the control group (chi(2) = 0.007, 0.002 and 0.064, respectively, P > 0.05). The frequencies of AA genotype and A allele in the A1438G polymorphisms of the serotonin 2A receptor genes in the OSAHS group [63.1% (41/65) and 74.6% (97/130), respectively] were significantly higher than those of the control one [27.8% (15/54) and 40.7% (44/108), respectively; chi(2) = 18.779 and 28.035, respectively, P < 0.01]. The OSAHS patients with AA genotype had higher obstructive apnea-hypopnea index (OAHI) and longest apnea time (LAT) than those with AG/GG genotype [OAHI were (40 +/- 9)/h, (25 +/- 9)/h and (20 +/- 11)/h, respectively, t = 6.674 and 7.753, respectively, P < 0.05; LAT were (94 +/- 10) s, (88 +/- 9) s and (75 +/- 12) s, respectively, t = 3.278 and 5.682, respectively, P < 0.05]. The lowest saturation of blood oxygen in patients with AA genotype was significantly lower than that in patients with AG/GG genotype [(69 +/- 12)%, (78 +/- 10)% and (80 +/- 9)%, respectively, t = 4.025 and 4.153, respectively, P < 0.05]. There was no significant difference in body mass index [(26.9 +/- 2.8) kg/m(2), (25.2 +/- 2.7) kg/m(2) and (26.0 +/- 3.7) kg/m(2), respectively], neck circumference [(43.3 +/- 2.7) cm, (42.6 +/- 1.8) cm and (42.8 +/- 2.1) cm, respectively] and waist/hip rate (0.89 +/- 0.12), (0.92 +/- 0.11) and (0.90 +/- 0.09), respectively, F = 0.859, 1.296 and 1.078, respectively, P > 0.05).

CONCLUSION

The T102C polymorphisms of the serotonin 2A receptor gene and the G796C polymorphisms of the serotonin 2C receptor gene may be not associated with OSAHS in subjects of "Han" population of China. The 1438 AA genotype of the serotonin 2A receptor gene may be involved in OSAHS, and the A allele may be an important candidate gene for OSAHS.

Prevalence and correlates of sleep-disordered breathing in older men: osteoporotic fractures in men sleep study

OBJECTIVES

To determine the prevalence and distribution of sleep-disordered breathing and associated correlates in a large cohort of older men using several standardized definitions.

DESIGN

Cross-sectional analyses.

SETTING

Six U.S. communities.

PARTICIPANTS

Polysomnography was performed on 2,911 participants of the Outcomes of Sleep Disorders in Older Men Sleep Study (mean age+/-standard deviation 76.38+/-5.53; body mass index 27.17+/-3.8 kg/m(2)).

MEASUREMENTS

Three outcomes were assessed: sleep-disordered breathing (respiratory disturbance index > or =15), obstructive apnea (obstructive apnea index > or =5), and central apnea (central apnea index > or =5).

RESULTS

The prevalence of moderate-severe sleep-disordered breathing was estimated to be 21.4% to 26.4%. Multivariable logistic regression models demonstrated that age (adjusted odds ratio (AOR) per 5-year increase =1.24, 95% confidence interval (CI)=1.15-1.34), obesity (AOR=2.54, 95% CI=2.09-3.09), Asian versus Caucasian race (AOR=2.14, 95% CI=1.33-3.45), snoring (AOR=2.01, 95% CI=1.62-2.49), sleepiness (AOR=1.41, 95% CI=1.11-1.79), hypertension (AOR=1.26, 95% CI=1.06-1.50), cardiovascular disease (AOR=1.24, 95% CI=1.19-1.29), and heart failure (AOR=1.81, 1.31-2.51) were independently associated with sleep-disordered breathing; snoring (AOR=2.10, 95% CI=1.67-2.70), age (AOR per 5-year increase=1.27, 95% CI=1.18-1.38), obesity (AOR=1.48, 95% CI=1.21-1.82), and heart failure (AOR=1.60, 95% CI=1.15-2.24) were associated with obstructive apnea; and age (AOR=1.33, 1.17-1.50) and heart failure (AOR=1.88, 95% CI=1.17-3.04) were associated with central apnea.

CONCLUSION

Regardless of definition, a high prevalence of sleep disorders is observed in community-dwelling older men. Qualitatively similar associations were observed between sleep disorders and snoring, obesity, and comorbidities, as reported for middle aged populations. Asian race was associated with sleep-disordered breathing.

Craniofacial abnormalities in Chinese patients with obstructive and positional sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is a common disorder characterized by recurrent episodes of a complete or partial collapse of the upper airway during sleep. Traditionally, the disease is diagnosed by overnight polysomnography. Studies have shown correlation between parameters of cephalometry and severity of sleep apnea. We wish to determine the variable of craniofacial dimensions in the upper airway that contribute to OSA, and to investigate the significance of craniofacial measurements in positional and non-positional sleep apnea patients.

METHODS

From July 2002 to June 2006, we studied 84 males and 15 females who came to the sleep center because of daytime sleepiness. All the participants underwent overnight polysomnography and lateral cephalograms, performed by an experienced technician.

RESULTS

Craniofacial measurements of gnathion-gonion, anterior superior hyoid to mandibular plane (MP-H), posterior nasal spine (PNS) to the velum tip (SPL), widest point of the soft palate (SPW), and the product of PNS to the velum tip and widest point of the soft palate (product of soft palate (SPP)=SPL x SPW) were positively related to the apnea/hypopnea index (AHI). The velum tip to the pharyngeal wall parallel to the Frankfurt horizontal (PAS) was negatively related to the AHI. We further divided the study subjects into 4 groups according to AHI value (group 1, AHI<5; group 2, 5 <or= AHI<15; group 3, 15 <or= AHI<30; group 4, AHI >or=30). Age, body mass index (BMI), neck circumference (NC), distances of PAS, SPL, SPW, SPP and angle of sella-nasion-infradentale (SNB) were significantly different depending on the degree of severity of sleep-disordered breathing (SDB). Patients who were older, with a high BMI and longer MP-H distance, had more daytime sleepiness (Epworth sleepiness scale, ESS). Furthermore, lower AHI values and longer PAS measurements were found in the positional sleep apnea group when compared to the non-positional sleep apnea group. After adjusting for confounding factors of age, BMI and NC, we found that BMI, MP-H distance and PAS measurement were correlated with severity of OSA.

CONCLUSIONS

Cephalometry could be a useful and inexpensive clinical tool to evaluate Chinese patients with OSA. MP-H and PAS should be measured in Chinese patients with OSA. MP-H was correlated with ESS. The PAS measurement was narrower in non-positional OSA patients compared to positional OSA patients.

Obstructive sleep apnoea in Asia

Obstructive sleep apnoea (OSA) syndrome is the commonest sleep-related breathing disorder worldwide. In Asia, the prevalence of symptomatic OSA in middle-aged men and women is 4.1-7.5% and 2.1-3.2%, respectively. These prevalence rates are similar to those reported in Caucasian populations. Obesity, an established major risk factor for OSA, is less common among Asians, and the reported values of body mass indices (BMIs) of Asians with OSA are lower than in their Caucasian counterparts. However, these population-based studies have consistently demonstrated that obesity is still the major risk factor for OSA in Asians, while other studies have suggested that craniofacial structural factors may make a greater contribution towards development of OSA in Asians than in Caucasians. Sleep medicine is in a developmental stage in many Asian countries, and the condition is likely under-recognised. Although sleep laboratories have been set up in various countries in Asia, the availability of this service is very limited. Continuous positive airway pressure is available in most parts of Asia, but financial constraints may limit its utility. Oral appliances have been postulated to have a greater role in the management of OSA in Asian patients, as they are likely to have more modifiable factors in their craniofacial structures, but this is yet to be proven. There is a great need for research and health care development on sleep disordered breathing in Asia, and the solution will only come with efforts towards promotion of awareness of this condition in both professional and lay communities.

Validation of a questionnaire instrument for prediction of obstructive sleep apnea in Hong Kong Chinese children

To develop and validate a questionnaire scale that can be used as a screening tool to investigate for the presence of childhood obstructive sleep apnea syndrome (OSAS) in Hong Kong Chinese children. Subjects suspected to have OSAS and controls were recruited. Parents completed a Hong Kong children sleep questionnaire (HK-CSQ) and all recruited subjects underwent at least one overnight polysomnographic study (PSG). An obstructive apnea index (OAI) >or= 1/h was diagnostic of OSAS. Receiver-operating characteristics (ROC) curve was constructed to determine optimal sensitivity and specificity. Reliability and validity of the questionnaire scale were also assessed. Two hundred twenty-nine children (149 boys and 80 girls) with a mean age of 10.0 years (SD = 2.1) were recruited. Their mean body mass index (BMI) and OAI were 19.8 (SD = 5.1) and 2.6 (SD = 7.6), respectively. Fifty-four boys and 12 girls were found to have OSAS. Three questions were found to be highly significant in predicting for the presence of OSAS-snoring, nocturnal mouth breathing, and sweating. A composite score of 7 from the three questions (range 0-12) was found to discriminate the OSAS cases best [ROC curve, AUC = 0.8 (95% CI = 0.8-0.9)]. The sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) were 75.4, 80.5, 61.3, and 88.9%, respectively. Test-retest reliability was undertaken in 51 subjects and the measurement of agreement (Kappa value) was 0.6. This HK-CSQ is a useful, valid, and reliable screening instrument for the presence of OSAS in children.

Insulin and obstructive sleep apnea in obese Chinese children

OBJECTIVE

In adults, obstructive sleep apnea (OSA) is associated with insulin resistance and dyslipidemia. We aimed to establish correlation between OSA, serum lipid profile, and insulin levels in obese snoring children.

METHODS

Consecutive obese children with habitual snoring were recruited. They underwent physical examination, overnight polysomnography (PSG), and metabolic studies. OSA was diagnosed if apnea hypopnea index (AHI) > 1.0, and cases were considered to have moderate to severe OSA if AHI > 10.

RESULTS

Ninety-four obese subjects with habitual snoring were studied. Seventy-three subjects were male and the median age of the studied group was 12.0 years (IQR 9.7-13.9). None of the subjects had active cardiopulmonary disease, and the BMI values of our subjects were >95th percentile using local reference charts. Sixty subjects had OSA, 47 being mild, and 13 being moderate to severe OSA. Multiple logistic regression analysis revealed that saturation nadir and insulin levels were significantly associated with OSA.

CONCLUSION

OSA is prevalent among obese children with habitual snoring and insulin is independently associated with the condition. Its role in the cardiovascular complications of childhood sleep apnea is worthy of further exploration.