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.

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.

Sleep of Māori and non-Māori of Advanced Age

AIM

To estimate prevalence and identify predictors and outcomes of reporting sleep problems in Māori and non-Māori of advanced age.

METHOD

Participants were 251 Māori, and 398 non-Māori adults (79-90 years) from Te Puāwaitanga o Ngā Tapuwae Kia Ora Tonu. Life and Living in Advanced Age: A Cohort Study in New Zealand. Multiple logistic regression identified predictors of reporting a current sleep problem and investigated relationships between current sleep problems and physical and mental health.

RESULTS

26.3% of Māori and 31.7% of non-Māori reported a current sleep problem. Reporting a current sleep problem was associated with ethnicity (non-Māori, adjusted OR=0.52, 95% CI=0.30-0.90), and reporting a past sleep problem (adjusted OR=2.67, 95% CI=1.25-5.72). Sleep problems were related to poorer physical and mental health, and falling.

CONCLUSION

Sleep problems are commonly reported and associated with poorer health. Early recognition and management of sleep problems could improve physical and mental health.

Examining the association between Apolipoprotein E (APOE) and self-reported sleep disturbances in non-demented older adults

We aimed to examine the association between Apolipoprotein E (APOE) and sleep disturbances. This is a cross-sectional study, from the Washington Heights-Inwood Community Aging Project (WHICAP). A total of 1944 non-demented older adults took part in the study. Sleep dysfunction was measured using sleep categories derived from the Medical Outcomes Study Sleep Scale. Genetic association between APOE-ϵ4 genotype and sleep disturbances was assessed using unadjusted linear regression models. Secondary analyses were conducted adjusting for age, sex, education, ethnicity and body mass index (BMI). In the unadjusted model, individuals carrying the APOE-ϵ4 allele showed lower levels of snoring (β=-0.02, SE=0.01, p=0.010) and sleep apnea (β=-0.01, SE=0.01, p=0.037) when compared to non-ϵ4 carriers. After covariates' adjustment, ϵ4 carriers demonstrated stronger association with lower levels of both snoring (β=-0.02, SE=0.01, p=0.006), and sleep apnea (β=-0.01, SE=0.01, p=0.018). Our results suggest that APOE-ϵ4 is associated with decreased problems in snoring and sleep apnea, in non-demented older adults.

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.

Self-reported sleep impairment and the metabolic syndrome among African Americans

OBJECTIVES

African Americans (AA) experience a high mortality from cardiovascular disease (CVD), even without an increase in the prevalence of the metabolic syndrome (MetS). The potential role of sleep impairment in this phenomenon has not been studied. The current study examined the relationship between self-reported sleep and MetS components among AAs. Sleep variables included total sleep quality and specific symptoms: loud snoring, difficulty breathing, and sleep duration.

DESIGN

Anthropometric (BMI, BP, waist circumference, body fat percent) and biologic (fasting glucose, triglycerides, total cholesterol, and HDL) measures were obtained from 248 community-recruited AA (63% female; mean age 44 years). The Pittsburgh Sleep Quality Index (PSQI), a 19-item scale with a total sleep quality score and 7 subscales, was used to assess self-reported sleep quality. Analyses were controlled for age and sex.

RESULTS

PSQI total sleep quality predicted neither presence of MetS (Beta=.04, P=.29) nor individual CVD variables. However, symptomatic snoring corresponded with MetS (Beta=.38, SE=.12, P<.001; OR: 2.57), as well as with fasting glucose, BMI, body fat percentage, and waist circumference.

CONCLUSIONS

Among AA, overall sleep quality as self-reported may not contribute to MetS, but symptomatic snoring appears to be important. Further work in this area should focus on sleep at the symptomatic level, and include racial and sex variables, as well as physiologic and etiologic mechanisms.

Association between sleep apnea, snoring, incident cardiovascular events and all-cause mortality in an adult population: MESA

BACKGROUND

We assessed the association between sleep apnea, snoring, incident cardiovascular (CV) events and all-cause mortality in the Multi Ethnic Study of Atherosclerosis (MESA) cohort.

METHODS

Out of 5338 respondents to a sleep questionnaire administered during the second MESA exam period, 208 had physician diagnosed sleep apnea (PDSA), 1452 were habitual snorers (HS) and 3678 were neither a habitual snorer nor had PDSA (normal participants). Cox proportional hazard analysis was used to assess the associations adjusting for age, gender, race/ethnicity, smoking, diabetes mellitus, total cholesterol, HDL, triglycerides, BMI, current alcohol use, benzodiazepine use, BP medications and statin use.

RESULTS

Over a 7.5 year average follow-up period, 310 adjudicated CV events including MI, stroke, angina, resuscitated cardiac arrest, stroke death and CVD death and 189 deaths occurred. Compared to HS, PDSA was associated with higher incident CV rates in both univariate and multivariable models [hazard ratio (95%); 1.89 (1.22-2.93), p = 0.004 and 1.91 (1.20-3.04), p = 0.007, respectively]. PDSA was also associated with a higher death rates compared with HS [hazard ratio (95%); 2.13 (1.25-3.63), p = 0.006 and 2.70 (1.52-4.79), p = 0.007, respectively]. Compared with normal participants, PDSA had higher incident CV event rates in both univariate and multivariable models [hazard ratio (95%); 2.23 [1.39-3.60], p = 0.001 and 2.16 [1.30-3.58], p = 0.003, respectively]. Similarly, PDSA had a higher death rate compared with normal participants in both the univariate and multivariable models [hazard ratio (95% CI); 2.44 (1.36-4.37), p = 0.003 and 2.71 (1.45-5.08), p =0 .002, respectively]. Habitual snorers had similar incident CV event rates and death rates in both univariate and multivariable models compared with normal participants.

CONCLUSION

PDSA but not habitual snoring was associated with high incident CV events and all-cause mortality in a multi-ethnic population based study of adults free of clinical CV disease at baseline.

Racial/ethnic differences in the prevalence of snoring and sleep disordered breathing in young children

STUDY OBJECTIVE

To determine whether there are racial/ethnic differences in the prevalence of pediatric snoring and sleep disordered breathing (SDB).

METHODS

In this cross-sectional study, parents or caretakers of 346 children, aged 2 through 6 years, attending well-child care visits at 5 general pediatric offices and clinics (3 academic, 2 private) in Brooklyn, NY completed the Sleep-Related Breathing Disorders Scale of the Pediatric Sleep Questionnaire (PSQ) along with a survey on demographics, prior treatment for SDB, and parental knowledge of pediatric SDB. The child's height and weight were recorded from the office visit.

RESULTS

The prevalence of snoring was 13.9% (95% CI 10.2, 17.5) and of SDB was 9.4% (95% CI 6.3, 12.6). The odds of snoring for black children was 2.5 as great as for white children, and for Hispanic children was 2.3 as great as for white children (p = 0.031). There was a higher, non-statistically significant prevalence of abnormal PSQ scores in black and Hispanic children than white children. On multivariate analysis, only black race (OR 3.1 95% CI 1.1, 8.9) and prematurity (OR 4.4 95% CI 1.6, 12.4) were associated with snoring; male gender (OR 2.9 95% CI 1.1, 8.5) was associated with SDB. Knowledge regarding SDB was low among parents and caretakers. The degree of knowledge present was not associated with parental concern about snoring and discussion of the snoring with the child's pediatrician.

CONCLUSIONS

Black race and prematurity are independent predictors of snoring. The degree of parental knowledge regarding SDB was not associated with seeking medical treatment.

Prevalence of sleep abnormalities and their association with metabolic syndrome among Asian Indians: Chennai Urban Rural Epidemiology Study (CURES-67)

OBJECTIVE

To estimate the prevalence of sleep abnormalities and their association with glucose intolerance and metabolic syndrome (MS) in the normal-weight urban South Indian population.

METHODS

This population-based, cross-sectional study was carried out in 358 subjects aged 20-76 years randomly selected from the Chennai Urban Rural Epidemiology Study in South India. A validated questionnaire assessing various sleep abnormalities (snoring, daytime sleepiness, lack of refreshing sleep, and number of hours of sleep) was administered. All subjects underwent an oral glucose tolerance test, and anthropometric biochemical measurements were obtained to assess cardiometabolic risk factors including glucose intolerance. Diabetes risk was assessed using a previously validated Indian Diabetes Risk Score (IDRS).

RESULTS

The overall prevalence of snoring and daytime sleepiness was 40% and 59%, respectively. Snorers were more male, older, smokers, and had higher levels of cardiometabolic risk factors. Subjects with daytime sleepiness had higher body mass index (BMI) and abdominal obesity. Both snoring (50.9% vs 30.2%, p<0.001) and daytime sleepiness (68% vs 49.7%, p<0.001) were more prevalent among subjects with impaired glucose metabolism compared to those with normal glucose metabolism. Both sleep measures were associated with higher diabetes risk scores, as assessed by the IDRS (snoring: trend χ2, 11.14, p=0.001; daytime sleepiness: trend χ2, 5.12, p=0.024). Metabolic syndrome was significantly associated with snoring even after adjusting for age, sex, family history of diabetes, physical activity, smoking, and alcohol.

CONCLUSIONS

The prevalence of snoring and daytime sleepiness is high among urban South Indians and these two sleep measures are associated with glucose intolerance, MS, and higher diabetes risk scores.

The prevalence of snoring in Thai pregnant women

OBJECTIVE

To determine the prevalence of snoring in Thai, pregnant women.

MATERIAL AND METHOD

This study was carried out from April 2008 through August 2008 at the antenatal clinic, HRH Princess Maha Chakri Sirindhorn Medical Center Nakorn Nayok province. Two hundred and thirty-eight pregnant women were enrolled. All subjects answered the Berlin questionnaire; this include information on age, weight, height, gravid health status, gestational age, witnessed incidences of snoring, and symptoms associated with sleep apnea. The description of snoring as frequency, volume, complaints from other people and bouts of sleep apnea were recorded and analyzed.

RESULTS

The prevalence of snoring in pregnancy was 35.29%. The snoring volume, recorded as slightly louder than breathing, in this group was 91.67%. One-fourth of the cases presented with snoring approximately 3-4 times a week with complaints of snoring bothering other people. The incidence of sleep apnea was found in 5.95% of this group.

CONCLUSION

The prevalence of snoring was found in approximately one-third of the pregnant women screened.

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.

[A cross-sectional study on snoring in Boertala Mongolia Autonomous Prefecture]

OBJECTIVE

To investigate the incidence and risk factors of snoring in Boertala Mongolia Autonomous Prefecture of Xinjiang.

METHODS

A random sample of 4444 people, aged > or = 30, from Mongolian, Kazakh, Uygur, and Han population in Boertala Mongolia Autonomous Prefecture was investigated for the presence of snoring and the risk factors.

RESULTS

The incidence of snoring was 21.8% (n = 967) in this sample population. The incidences of snoring adjusted by age and gender were 30.3%, 16.4%, 23.5%, and 19.5%, respectively in Mongolian, Kazakh, Uygur, and Han populations. The ratios of smoking and alcohol consumption were higher in subjects of snoring (43.4% vs 27.8%, and 40.5% vs 24.2%, respectively). Multiple unconditional logistic regression analysis showed that body mass index (BMI) was the major risk factor for snoring. Neck circumference was significantly correlated with snoring in Kazakh and Mongolian, populations. Alcohol consumption was a risk factor for snoring in Mongolian, Kazakh, and Han populations.

CONCLUSION

The prevalence of snoring is high in Boertala Mongolia Autonomous Prefecture of Xinjiang, especially in the Mongolian population. BMI, neck circumference and alcohol consumption were risk factors for snoring.

Snoring and vascular risk factors and disease in a low-risk Chinese population: the Guangzhou Biobank Cohort Study

STUDY OBJECTIVE

Snoring is a common condition, but data describing the relationship between snoring and vascular disease is very limited in Asian populations. We therefore describe the association between snoring and vascular disease and associated risk factors.

DESIGN

Cross-sectional study of baseline data from the Guangzhou Biobank Cohort Study.

SETTING

Community-based elderly association from Guangzhou, China.

PARTICIPANTS

10413 Chinese subjects (50-85 years of age).

MEASUREMENTS

Self-reported snoring status and frequency and frequency of daytime tiredness were collected by questionnaire, as were demographic and socioeconomic data, disease histories, and potential confounders, such as smoking and alcohol consumption. Anthropometry, blood pressure, and fasting glucose and lipid profile were also measured.

RESULTS

Self-reported snoring frequency was identified in 8325 (80.0%) subjects, with 51.6% reporting that they snored, of whom 15.5% were daily snorers. Increasing prevalence of snoring showed a clear positive relationship with cardiovascular risk factors, including age, obesity, blood pressure, and lipid levels (p < .001 for all). The prevalence of self-reported vascular-disease history was low but significantly associated with increasing snoring frequency. Logistic regression showed that snoring frequency was an independent predictor of vascular-disease history (odds ratios [95% confidence intervals] 1.68 [1.32-2.13] for daily snorers compared with the never-snorer reference group), of the metabolic syndrome (2.16 [1.88-2.49]) and each of its components (hypertension [1.37 (1.20-1.56)], and of dyslipidemia [1.22 (1.07-1.40)], central obesity [2.39 (2.08-2.76)], and diabetes [1.30 (1.09-1.56)]) after adjustment for potential confounders.

CONCLUSION

Increasing snoring frequency was associated with an increasing prevalence of risk factors and self-reported vascular disease. Snoring may a useful marker for increased risk of vascular disease.

Risk factors associated with habitual snoring and sleep-disordered breathing in a multi-ethnic Asian population: a population-based study

INTRODUCTION

There is scant data on the risk factors of sleep-disordered breathing (SDB) in the general population in Asian countries.

METHODS

Cross-sectional survey of a random population sample of 2298 adults aged 20-75 years, stratified by gender, ethnicity (Chinese, Malay and Indian) and age. An interviewer-administered questionnaire was used to elicit responses to questions on daytime somnolence and nocturnal events. Three categories of SDB were defined for analysis: habitual snoring; apnoeic snoring (SDB I); and apnoeic snoring or snoring with diurnal hypersomnia (SDB II).

RESULTS

Snoring was reported by 201 persons (6.8%), SDB-I in 44 (1.9%) and SDB-II in 112 (4.9%) in the sample. The adjusted odds ratio (95% C.I.) of association with snoring were: male gender, 3.79 (2.69-5.33); older age (>60 years old), 2.15 (1.41-3.29); Indian versus Chinese, 1.54 (1.05-2.25); family history, 2.21 (1.56-3.12); obesity (BMI>30), 2.64 (1.62-4.30); neck circumference (>40 cm), 2.57 (1.59-4.11); and cigarette smoking, 2.05 (1.21-3.45). The risk factors for SDB were similar to that of snoring.

CONCLUSION

Population risk factors associated with habitual snoring and SDB in Singapore are largely similar to those reported in other populations. Differential risks underscore the importance of ethnicity in determining the burden of SDB.

Symptoms related to sleep-disordered breathing in white and Hispanic children: the Tucson Children's Assessment of Sleep Apnea Study

STUDY OBJECTIVES

The Tucson Children's Assessment of Sleep Apnea (TuCASA) study is designed to investigate the prevalence and correlates of objectively measured sleep-disordered breathing (SDB) in preadolescent children. This article describes the parental report of sleep symptoms associated with SDB in Hispanic and white children.

DESIGN

A 13-question sleep habits screening questionnaire designed to assess the severity of sleep-related symptoms associated with SDB in children 4 to 11 years of age.

SETTING

Questionnaires were completed by the parents of children attending elementary school in the Tucson Unified School District, Tucson, AZ.

PARTICIPANTS

There were 1,494 questionnaires returned, which comprised a sample of whites (38%), Hispanics (45%), and other races (17%). Of these questionnaires, 1,214 were returned for the children of white (45.8%; 556 children) or Hispanic (54.2%; 658 children) ethnicity only. The primary analysis was completed on these 613 boys (50.5%) and 601 girls (49.5%).

RESULTS

In the total sample of 1,494 children, parents were more likely to report excessive daytime sleepiness (EDS) in female children than in male children (p <.01), however, this association did not achieve significance in the sample of only white and Hispanic children (p <.07). Composite variables for EDS and witnessed apnea (WITAP) show that parents of Hispanic children were more likely to report EDS (p <.01) and WITAP (p <.007). Hispanic children were also more likely to have learning problems (LPs) [p <.03] and to snore frequently (SN) [p <.02] than were white children. There were no significant differences between boys and girls for SN or WITAP. Hispanic boys were more likely to have reports of EDS (p <.02) and LPs (p <.04) than white boys, however, there were no other significant differences in gender or ethnicity in reports of EDS or LPs for white or Hispanic boys and girls. Those children with frequent LPs were significantly more likely to have SN (p <.001), EDS (p <.001), and WITAP (p <.001). A logistic regression model predicting LP resulted in significant adjusted odds ratios (ORs) of 2.4 for SN, 2.5 for EDS, and 2.1 for children aged 8 to 11 years. A similar model for EDS resulted in significant adjusted ORs of 3.2 for SN, 5.7 for WITAP, and 1.6 for female gender. Ethnicity was not significant in either model.

CONCLUSIONS

Hispanic children in the population-based TuCASA study experienced more frequent symptoms associated with SDB, such as SN, EDS, WITAP, and LPs, than did white children. Children with LPs are 2.4 times more likely to have SN, 2.5 times more likely to have EDS, and were 2.1 times more likely to be between the ages of 8 and 11 years. Children with EDS were 3.2 times more likely to have SN, 5.7 times more likely to have WITAP, and were 1.6 times more likely to be a girl.

Cephalometric assessment of craniofacial morphology in Chinese patients with obstructive sleep apnoea

OBJECTIVE

To compare the differences in craniofacial morphology in Chinese patients with and without obstructive sleep apnoea (OSA).

METHOD

We performed lateral cephalometric radiographs on 94 consecutive patients (77 males) referred with snoring or other symptoms suggestive of OSA for polysomnography (PSG). Significant OSA was defined as an apneoa-hypopnoea index (AHI) > or = 10/h of sleep on overnight PSG. The cephalometric data were compared between those with and without significant OSA.

RESULTS

(mean +/- SD) There were 69 (56 males) with significant OSA with mean age 53 +/- 12 years, body mass index (BMI) 28.6 +/- 5.0 kg/m2, AHI 36.5 +/- 20.6/h, and minimum SaO2 76 +/- 14%. There were 25 controls (21 males) without significant OSA with similar age and BMI. The mandibular plane to hyoid bone distance (MPH) and the perpendicular distance from hyoid bone to the line connecting C3 vertebra and retrognathion (HHI) were significantly longer in the OSA patients. The angle measurement from sella to nasion to point A (SNA) was smaller in the OSA group. MPH distance was the only independent variable for significant OSA with an odds ratio of 3.47 (95% CI 1.39-8.66). Abnormalities of the MPH and SNA were more marked in the OSA patients with BMI > or = 30 kg/m2.

CONCLUSIONS

Significant differences in craniofacial morphology are noted between OSA patients and non-apnoeic controls. An inferiorly positioned hyoid bone and a retropositioned maxilla may predispose obese patients to more severe OSA.

Airway assessment by volumetric computed tomography in snorers and subjects with obstructive sleep apnea in a Far-East Asian population (Chinese)

OBJECTIVES

To evaluate the airway dimension of simple snorers and subjects with obstructive sleep apnea (OSA) in a Far-East Asian population (Chinese).

STUDY DESIGN

Prospective study of 117 near-consecutive patients evaluated for snoring and possible OSA from January 1998 to December 1998 in a sleep laboratory. Overnight polysomnography (PSG) was performed on all patients and the sleep parameters, including respiratory disturbance index (RDI), snoring index, minimal oxygen saturation (min O2), percentage of slow wave sleep (SWS), and rapid eye movement (REM) were recorded. Three-dimensional computerized tomography (CT) during awake periods was performed. The anteroposterior (AP) and the lateral distance of the retropalatal (RP) region in the oropharynx, the smallest area of RP, and retroglossal (RG) regions, and the total volume of the oropharynx were measured.

RESULT

Ninety-eight patients were diagnosed with OSA (mean RDI, 41.48 +/- 26.45 events per hour; min O2, 72.82 +/- 12.86%), whereas 19 were simple snorers. The AP and the lateral distance of the RP region, as well as the smallest area of the RP region, are significantly smaller in subjects with OSA. However, no differences in the RG region and the total volume of the oropharynx were found between the two groups. Linear regression analysis demonstrated that the lateral dimension and the smallest RP area in overweight subjects inversely correlated with the RDI, but only the AP dimension of the RP area was found to have an inverse correlation with the RDI in the underweight subjects.

CONCLUSION

In Far-East Asians (Chinese), the RP airway was found to be the primary site of narrowing in subjects with OSA, and the narrowest RP area was inversely correlated with RDI. Furthermore, weight may influence the pattern of RP narrowing by contributing to lateral collapse.

Snoring & sleep apnea: a population study in Italian women

The aim of this cross-sectional study was to evaluate the prevalence of sleep-disordered breathing by means of a validated portable instrument (MESAM IV) and to investigate the relationship between snoring and sleep apnea in a sample of Italian middle-aged female population. We randomly chose 750 subjects aged 40 to 65 years and 365 agreed to participate to the study. In this group, 19.7% of subjects were every-night snorers according to the questionnaire; when recorded, 54.2% snored for more than 10% of the night, and 7.1% for more than 50% of the night. Sleep apnea was also common: 10.7% of subjects had a respiratory disturbances per hour (RDI) between 5 and 9, 7.7% an RDI between 10 and 19, and 2.2% had an RDI > or =20. Snoring percentage and RDI were significantly correlated. However, 50% of subjects who snored for more than half the night had no evidence of sleep apnea. Snoring amount >50% resulted influenced by body mass index, while RDI>10 was influenced by neck diameter. We concluded that in middle-aged women, both snoring and sleep apnea are very common. A high percentage of snoring is not essential for the occurrence of sleep apnea, nor it necessarily indicates the presence of sleep apnea.

Ethnicity, obstructive sleep apnoea and ischaemic heart disease

We studied the relationship between different ethnic groups, obstructive sleep apnoea (OSA) and ischaemic heart disease. Four hundred and thirty-two inpatients from the medical wards were interviewed. Limited overnight sleep studies were done in 129 of those who had habitual snoring, daytime sleepiness based on an Epworth sleepiness scale of 8 or more, or a large neck size of 40 cm or more. There were 315 Chinese (72.9%), 67 Malays (15.5%), 43 Indians (10%) and 3 from other races (1.4%). The prevalence of OSA was 19.7%, 30% and 12% among the Chinese, Malays and Indians, respectively. The prevalence ratio for OSA was 1.52 in Malays using Chinese patients as the baseline (P = 0.07). The median neck circumference was 37 cm in both racial groups. The median body mass index was 22.7 kg/m2 in Chinese compared to 23.6 kg/m2 in Malays. The median apnoea-hypopnoea index was 22.7, 19.0 and 26.9 events/hour among the Chinese, Malays and Indians, respectively. OSA was independently associated with the prevalence of IHD (adjusted prevalence ratio 1.68; 95% CI: 1.15, 2.46; P = 0.009). The prevalence of ischaemic heart disease (IHD) was 31%, 24% and 28% in Chinese, Malays and Indians, respectively. The prevalence ratio for IHD in Malays compared to Chinese was 0.77. After adjusting for OSA, there was an even greater reduction in the risk of IHD (adjusted prevalence ratio 0.70). This suggests that OSA is a confounder in the relationship between race and ischaemic heart disease.

Prevalence of snoring and sleep breathing-related disorders in Chinese, Malay and Indian adults in Singapore

This study investigated the prevalence of snoring and symptoms of sleep breathing-related disorders in the multi-ethnic population of Singapore (3 million people, comprising 75% Chinese, 15% Malay and 7% Indian). A multistaged, area cluster, disproportionate stratified, random sampling of adults aged 20-74 yrs was used to obtain a sample of 2,298 subjects (65% response), with approximately equal numbers of Chinese, Malay and Indian and in each 10 yr age group. An interviewer-administered field questionnaire was used to record symptoms of snoring and breathing disturbances during sleep witnessed by a room-mate and other personal and health-related data. The weighted point estimate (and 95% confidence interval) of the whole population prevalence of snoring was 6.8% (53-83). There were pronounced ethnic differences among Chinese, 6.2% (4.4-8.1); Malay, 8.1% (6.1-10.2) and Indian, 10.9% (85-13.4). The minimum whole population prevalence by the most restricted symptom criteria for defining sleep breathing-related disorder was 0.43% (0.05-0.8%). Similar marked ethnic differences in rates were observed using various symptom criteria. The ethnic differences in sleep breathing symptoms paralleled the differences in body mass index, neck circumference and hypertension, but statistically significant differences remained after adjustment for sex, age and these known associated factors. Marked ethnic differences in snoring and sleep breathing-related disorders were observed in Chinese, Malays and Indians in Singapore, which were only partly explained by known factors of sex, age and body habitus.

Snoring in a Hispanic-American population. Risk factors and association with hypertension and other morbidity

Snoring was investigated in a survey of respiratory disease in Hispanic-Americans of a New Mexico community. A population-based sample of 1222 adults was studied with questionnaires and measurements of height, weight, and blood pressure. The age-adjusted prevalence of regular loud snoring was 27.8% in men and 15.3% in women. Snoring prevalence increased with age and obesity in both men and women. Cigarette smoking was also associated with snoring, but chronic obstructive lung disease and alcohol consumption were not. Snorers more frequently had hypertension, ischemic heart disease, and excessive daytime sleepiness. In contrast to other studies, after adjustment for confounding factors, there was no effect of snoring on hypertension (odds ratio, 1.0; 95% confidence interval, 0.7 to 1.5), but an effect on myocardial infarction was still demonstrable (odds ratio, 1.8; 95% confidence interval, 0.9 to 3.6). The association of snoring with sleepiness suggests that respiratory disturbance of sleep related to upper airway obstruction, such as sleep apnea, occurs more frequently in snorers in this population.