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

ABSTRACT: 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.

Unequal Rates of Serious Perioperative Respiratory Adverse Events Between Black and White Children.

BACKGROUND: Recent data among pediatric otolaryngology patients showed unexplained higher rates of serious perioperative respiratory adverse events (PRAE) in black children compared to their white peers. We evaluated whether preoperative respiratory comorbidity (PRC) burden contributes to racial disparity in serious PRAE in children undergoing non-otolaryngologic procedures. METHODS: Rates of serious PRAE (laryngospasm and/or bronchospasm) were compared across racial groups in a retrospective cohort of black and white children (N = 18538; black 10%) who underwent various elective, non-otolaryngologic procedures between 2007 and 2014 at a US tertiary Children's hospital. Self-reported race was the primary exposure while age, gender, recent upper respiratory tract infection, use of endotracheal intubation, PRC burden and an interaction term between PRC and race were covariates. RESULTS: Serious PRAE occurred in 9.6% of black children and 6.6% of white children. Although there was no significant difference in age between the groups, being black (odds ratio (OR) 1.70; 95% confidence interval (CI) 1.11-2.62) was independently associated with serious PRAE. Similarly, baseline PRC was independently linked (p < 0.001) with serious PRAE. Notably, there was no significant (p = 0.454) interactions between race and PRC and serious PRAE in our subjects. CONCLUSION: Race and PRC are important considerations in the risk of serious PRAE and black children are especially at risk compared to their white peers. Children, with PRC (particularly those with SDB and asthma) are also at risk suggesting that due consideration should be given to these factors in the perioperative care of children undergoing elective surgical procedures. Mechanisms underlying these associations deserve further evaluation.

Snoring and components of metabolic syndrome in Southeastern Chinese adults: A community-based study.

INTRODUCTION: Snoring has been associated with a number of abnormal conditions, but little work has been done on its association with components of metabolic syndrome based on the epidemiology in Chinese adults. OBJECTIVE: This study aimed to investigate the association between snoring and components of metabolic syndrome in southeastern Chinese adults. METHODS: A two-stage, cross-sectional community-based study was performed in Fuzhou, Southeast China, from 2005 to 2009. Stage 1: 5500 subjects were administered a questionnaire. Data on self-reported snoring status, daytime somnolence, demographic data, disease histories, and potential confounders were collected and anthropometric measurements were performed. Stage 2: 1000 subjects who were already investigated underwent a blood test and measurement of blood pressure. RESULTS: Data from 4286 subjects were available; 606 subjects were habitual snorers. The prevalence of overweight or obesity, hyperglycemia, hypertension, and dyslipidemia in occasional and habitual snorers was higher than that in the study population (16.66%, 7.89%, 10.52%, and 5.81%, respectively). A significantly increasing trend based on snoring frequency existed in the prevalence of metabolic disorders. The prevalence of components of metabolic syndrome continued to be significantly associated with snoring frequency after controlling confounding factors. Odds ratios of suffering from the aforementioned conditions for occasional and habitual snorers were 1.5-2.5 (P < 0.05) and 2.4-4.8 (P < 0.001) times higher, respectively, compared with nonsnorers. CONCLUSIONS: The prevalence of snoring and components of metabolic syndrome is high in southeastern Chinese adults. Both habitual and occasional snoring are closely associated with metabolic disorders independent of confounding factors.

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' ß = 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.

Disparities and genetic risk factors in obstructive sleep apnea.

Obstructive sleep apnea (OSA) is an increasingly prevalent condition. A growing body of literature supports substantial racial disparities in the prevalence, risk factors, presentation, diagnosis, and treatment of this disease. Craniofacial structure among Asians appears to confer an elevated risk of OSA despite lower rates of obesity. Among African Americans, Native Americans, and Hispanics, OSA prevalence is increased, likely due in part to obesity. The burden of symptoms, particularly excessive daytime sleepiness, is higher among African Americans, although Hispanics more often report snoring. Limited data suggest that African Americans may be more susceptible to hypertension in the setting of OSA. While differences in genetic risk factors may explain disparities in OSA burden, no definitive genetic differences have yet been identified. In addition to disparities in OSA development, disparities in OSA diagnosis and treatment have also been identified. Increased severity of disease at diagnosis among African Americans suggests a delay in diagnosis. Treatment outcomes are also suboptimal among African Americans. In children, tonsillectomy is less likely to cure OSA and more commonly associated with complications in this group. Among adults, adherence to continuous positive airway pressure (CPAP) is substantially lower in African Americans. The reasons for these disparities, particularly in outcomes, are not well understood and should be a research priority.

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 (ß=-0.02, SE=0.01, p=0.010) and sleep apnea (ß=-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 (ß=-0.02, SE=0.01, p=0.006), and sleep apnea (ß=-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.

Environmental factors that can affect sleep and breathing: allergies.

Allergic rhinitis and associated symptomatic nasal obstruction negatively affect sleep through a variety of mechanisms and may contribute to persistent symptoms and poor adherence with medical device therapy for sleep apnea. A history of sinonasal symptoms, particularly those that occur at night or in the supine position, is the cornerstone of the medical evaluation. Further research into the relationship between allergic rhinitis and sleep disturbance would benefit from improved anatomic and pathophysiologic phenotyping as well as more advanced outcome measures such as spectral electroencephalogram analysis or other polysomnography variables beyond the apnea-hypopnea index.

Race/ethnic differences in obstructive sleep apnea risk in patients with acute ischemic strokes in south Florida.

PURPOSE: Obstructive sleep apnea (OSA) is a risk factor for ischemic stroke, but it may differ between race/ethnic groups. The goal of our study was to examine the pre-stroke risk of OSA between three race/ethnic groups admitted for acute ischemic stroke in a tertiary urban hospital in South Florida. METHODS: Our sample was composed of patients with acute ischemic strokes evaluated at a teaching hospital over a 3-year period. Race/ethnicity was defined by self-identification, modeled after the US census and categorized into non-Hispanic whites, non-Hispanic blacks, and Hispanics. Pre-stroke risk of OSA was assessed with the Berlin questionnaire and categorized into high- or low-risk categories. We performed binary logistic regression to evaluate the pre-stroke risk of OSA in Hispanics and non-Hispanic blacks with non-Hispanic whites as the reference, adjusting for age, body mass index, hypertension, diabetes, and smoking. RESULTS: There were 176 patients with acute ischemic strokes of which 44 % were Hispanics, 44 % non-Hispanic Blacks, and 12 % non-Hispanic whites. A higher frequency of patients at high risk for OSA was seen in 60 % of Hispanics, 54 % of non-Hispanic blacks, and 33 % of non-Hispanic whites. Hispanics (OR, 2.6; 95 % CI 1.1-6.4) had a higher frequency of patients at high risk for OSA compared to non-Hispanic whites, adjusting for covariates. There were no differences between non-Hispanic blacks (OR, 1.2; 0.5-2.9 and non-Hispanic whites. DISCUSSION: We observed higher frequency of patients at high risk for OSA in Hispanics with acute ischemic strokes in South Florida.

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.

Functional outcomes of sleep in Thai patients with obstructive sleep-disordered breathing.

PURPOSES: Quality of life assessment in obstructive sleep-disordered breathing (OSDB) is increasingly recognized, and the functional outcomes of sleep questionnaire (FOSQ) is a popular instrument. The objective of this study was to apply this questionnaire in Thai patients to assess its reliability, validity, and responsiveness properties. METHODS: A total of 223 subjects were recruited. The scores of FOSQ in 38 healthy volunteers and 40 primary snorers were compared with those of 108 obstructive sleep apnea (OSA) patients diagnosed by polysomnography. Seventy-two subjects answered the FOSQ twice at 2-4 weeks apart to check the test-retest reliability, and 37 patients with OSA who complied well with CPAP therapy answered them again after treatment at 3-6 months. All participants also filled the Epworth sleepiness scales (ESS) to check the concurrent validity. RESULTS: There were statistically significant differences in all FOSQ subscales including global scores between healthy volunteers (17.3 ± 2.1) and OSA patients (14.5 ± 2.9) (p < 0.001). The internal consistency of the questionnaire was excellent (Cronbach's alpha 0.95), and the test-retest reliability (intra-class correlation coefficients) was 0.70 in global scores. After adequate CPAP therapy, all FOSQ scores increased significantly (p < 0.001) There were significant correlations between all FOSQ scores except sexual relationship and ESS (r -0.48); however, these had only a weak relationship with AHI and minimal oxygen saturation. CONCLUSIONS: The FOSQ can be applied to Thai patients with OSDB with good reliability, validity, and responsiveness properties. It may be the first validated version of FOSQ in East Asian countries which is a very useful tool for future research.

Clinical and polysomnographic data of positional sleep apnea and its predictors.

INTRODUCTION: In Asian population, facial structure may contribute to the primary pathophysiology of obstructive sleep apnea (OSA). We hypothesized that sleep position may have more effect on OSA in Asians compared to the Western population. If this hypothesis is accurate, positional therapy will have a major impact on treatment of OSA among Asians. PATIENTS/METHODS: We reviewed 263 polysomnographic studies from our laboratory from January 1, 2010 to June 30, 2010. Criteria for positional and non-positional OSA were (1) supine respiratory disturbance index (RDI)/non-supine RDI ≥2 and total RDI ≥5 and (2) supine RDI/non-supine RDI <2 and total RDI ≥5, respectively. We aimed to determine the difference in baseline characteristics, polysomnographic findings, and predictors for positional OSA. RESULTS: We found 144 patients diagnosed with OSA (RDI ≥5), and 96 patients met the criteria for positional OSA (67%), in which in almost half of these patients (47%), RDI was normalized (RDI < 5) in non-supine position. Snoring frequency were significantly lower among positional OSA and OSA was less severe indicated by lower RDI and arousal index, higher mean and nadir oxygen saturation, and higher %NREM3. We also found that low snoring frequency (less than 20% of total sleep time) was a significant predictor for positional OSA (odd ratio of 3.27; p = 0.011), contrarily to low mean oxygen saturation (<95%) which was found to be a negative predictor (odd ratio of 0.31; p = 0.009). Among OSA patients, low RDI (<15) was a significant predictor for normalization of RDI in non-supine position (odd ratio of 8.77; p = < 0.001), contrarily to low mean oxygen saturation (<95%) which was also found to be a negative predictor (odd ratio of 0.13; p = 0.001). CONCLUSION: Positional OSA is very prevalent and noted in almost 70% of our patients. Low snoring frequency was noted to be a positive predictor for positional OSA, contrarily to low mean oxygen saturation which was found to be a negative predictor. These findings are encouraging that positional therapy can be very beneficial as the treatment modality for OSA among Asians.

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.

'A good shepherd, but with obstructive sleep apnoea syndrome': traditional uvulectomy case series and literature review.

BACKGROUND: In the West, removal of the uvula is predominantly undertaken as part of palatal surgery, in cases of obstructive sleep apnoea. In the developing world, such as the Middle East and Africa, uvulectomy is a more common practice. The uvula is removed for curative or preventive purposes, or as part of ritual practice. Due to immigration from developing to developed world countries, and to Western doctors working abroad, such doctors are increasingly being confronted with unfamiliar traditional healing practices, within a medical context. METHODS: The Medline and Embase online databases were systematically searched for literature on traditional uvulectomy. We present a review of this literature. We also present the first report, to our best knowledge, of obstructive sleep apnoea as a late complication of traditional uvulectomy. DISCUSSION: Traditional uvulectomy may be complicated by post-operative haemorrhage and local infections, among many other problems. We report cases of obstructive sleep apnoea and snoring caused by palatal stenosis resulting from traditional uvulectomy during childhood.

Risk factors for snoring among Japanese men and women: a community-based cross-sectional study.

PURPOSE: This study seeks to examine risk factors for snoring, a major symptom of sleep-disordered breathing (SDB) because the evidence is limited in Asian populations. METHODS: Subjects for the present cross-sectional study were 3,138 men and 5,345 women aged 35­79 years from three communities in Japan who participated in the Circulatory Risk in Communities Study. The data on snoring frequency and cardiovascular health were obtained during annual cardiovascular surveys between 2000 and 2005. The logistic regression model was used to estimate the odds ratios (ORs) for snoring associated with body mass index (BMI), alcohol consumption, and other cardiovascular risk factors. RESULTS: The prevalence of almost everyday snoring was 24% among men and 10% among women. After adjustments for age, community, cigarette smoking, alcohol consumption, and for women, menopausal status, the multivariable-adjusted ORs for everyday snoring in the highest versus lowest quartiles of BMI categories were 3.4 (95% confidence interval (CI): 2.6­4.4) for men and 3.9 (2.8­5.4) for women. The respective ORs in ≥23 g ethanol per day versus never-drinkers categories were 1.4 (1.1­1.8) and 3.1 (1.8­5.3) and those in ≥20 cigarettes versus never-smokers categories were 1.4 (1.0­1.8) and 1.9 (0.9­3.7). The associations of alcohol consumption and cigarette smoking with everyday snoring were stronger for BMI<25 kg/m2 than BMI≥25 kg/m2 in both sexes. CONCLUSION: BMI, alcohol consumption, and cigarette smoking were positively associated with habitual snoring for both men and women, especially in nonoverweight persons.

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.

Prevalence and risk factors of syndrome Z in urban Indians.

BACKGROUND: Syndrome Z is defined as the co-occurrence of obstructive sleep apnea (OSA) and metabolic syndrome. There is a paucity of information on the magnitude of syndrome Z in the community and the factors associated with it. METHODS: We conducted a two-stage, cross-sectional, community-based study in four different socioeconomic zones of the South Delhi district, India, from April 2005 through June 2007. In stage 1, a systematic random sample of subjects of either gender aged 30-65 years were administered a questionnaire by door-to-door survey. Subjects that responded were classified as habitual and non-habitual snorers. In stage 2, all the habitual and 10% of randomly selected non-habitual snorers were invited for overnight polysomnography and evaluation for metabolic syndrome. The National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) criteria were used to define metabolic syndrome. RESULTS: Of the 2860 subjects approached, 2505 (88%) completed stage 1; 452 (18%) were habitual snorers. In stage 2, OSA (defined as apnea-hypopnea index > or =5) was observed in 94 (32.4%) of 290 habitual snorers and 3 (4%) of 75 non-habitual snorers. Seventy (77%) of the 91 habitual snorers with OSA also had metabolic syndrome; none of the non-habitual snorers with OSA had metabolic syndrome. The estimated population prevalence of metabolic syndrome was 43% [95% CI: (41.0-44.9%)] and syndrome Z was 4.5% (95% CI: 3.7-5.3). On multivariable analysis, age [OR: 1.05 (1.00-1.09)], male gender [OR: 5.64 (2.06-15.49)], percent body fat [OR: 1.08 (1.04-1.13)] and DeltaSaO(2) (%) (defined as the difference between baseline and minimum SaO(2) during overnight sleep study) [OR: 5.80 (2.36-14.26), 17.70 (5.97-52.17) and 57.1 (19.12-170.40) for 10-20%, 20-30% and >30% reduction respectively as compared to <10% reduction] were independently associated with syndrome Z. CONCLUSIONS: To the best of our knowledge, this is the first population-based study on the prevalence and risk factors of syndrome Z, and it reveals that a considerable proportion of community-dwelling northern Indian adults have syndrome Z. Age, male gender, percent body fat and severity of nocturnal desaturation were independent risk factors for syndrome Z.

Uric acid excretion in North American and Southeast European children with obstructive sleep apnea.

BACKGROUND AND OBJECTIVES: Responses to nocturnal hypoxemia accompanying sleep-disordered breathing (SDB) may vary in different populations. Aims of this study were to (1) assess whether severity of SDB is related to uric acid excretion in North American and Southeast European children and (2) evaluate the interaction between nocturnal hypoxemia and country of children's origin in uric acid excretion. METHODS: Consecutive US and Greek children with snoring who were referred for polysomnography were recruited. Uric acid excretion expressed as uric acid-to-creatinine concentrations ratio in a morning urine specimen was the primary outcome measure. RESULTS: One hundred and twenty-six US children (6.8+/-0.7years old) and 123 Greek children (6.4+/-2.5years old) were recruited. Forty-three US and 53 Greek participants had moderate-to-severe nocturnal hypoxemia (SpO(2) nadir <90%). Obstructive apnea-hypopnea index and SpO(2) nadir were related to uric acid excretion in Greek (but not US) children after adjustment by age, gender and body mass index z-score (p<0.05). There was a significant interaction between severity of hypoxemia and country of children's origin in uric acid excretion after adjustment by age, gender and body mass index z-score (p=0.036). Greek children with moderate-to-severe hypoxemia had higher uric acid excretion (0.85+/-0.35) than those with mild/no hypoxemia (0.69+/-0.25) (p=0.005). US children with moderate-to-severe hypoxemia (0.41+/-0.20) did not differ in uric acid excretion from those with mild/no hypoxemia (0.42+/-0.22) (p=0.823). CONCLUSIONS: Uric acid excretion differs in children with SDB and different ethnic backgrounds or environmental exposures.