Lower BMI is a predictor of obstructive sleep apnea in elderly Thai hypertensive patients

Purpose

The prevalence of both hypertension and obstructive sleep apnea (OSA) are increased in patients with age greater than 60 years. We studied the clinical differences of OSA in hypertensive patients with age greater or less than 60 years. In addition, rate of OSA-induced hypertension in Thai population is limited.

Methods

We retrospectively reviewed medical records of patients treated at the hypertension/sleep clinic at Srinagarind Hospital, Khon Kaen University, between 2010 and 2011. The inclusion criteria used were hypertensive patients who had at least one symptom of OSA and had been tested for the sleep study. Rate and clinical features of OSA were studied and categorized by age of 69 years. Factors associated with likelihood of having OSA in hypertensive patients age over 60 years were identified by multiple logistic regression analysis.

Results

During the study period, 49 patients met the criteria. Of those, 42 patients (85.71 %) had an apnea–hypopnea index (AHI) of more than 5/h. The average AHI was 22.22?±?13.86 times/h. The common symptoms of OSA were snoring (100 %), daytime sleepiness (28.57 %), unexplained nocturia (28.57 %), and gastroesophageal reflux disease (28.57 %). The numbers of patients with age less than 60 years and more than 60 years were 20 and 22 cases, respectively. Most patients (88.10 %) had well-controlled blood pressure level. Only BMI was significantly associated with OSA-induced hypertension in patients aged over or equal to 60 years. The adjusted odds ratio was 0.743 (0.560, 0.985).

Conclusions

OSA is very common in Thai hypertensive patients aged 40–70 years who have at least one symptom of OSA. Lower BMI is a predictor of obstructive sleep apnea in elderly Thai hypertensive patients     

High prevalence of undiagnosed obstructive sleep apnoea in the general population and methods for screening for representative controls

Purpose

Undiagnosed obstructive sleep apnoea (OSA) in the community makes comparisons of OSA subjects with control samples from the general population problematic. This study aims to estimate undiagnosed moderate to severe OSA in a general population sample and to determine the capacity of questions from the Berlin questionnaire (BQ) to identify subjects without diagnosed OSA of this severity.

Methods

Using a general population sample (n?=?793) with no history of OSA, case and control status for moderate–severe OSA was determined by home-based nasal flow and oximetry-derived apnoea–hypopnoea index using a cut-off value of ≥15 events/h to define cases. The diagnostic accuracy of the complete BQ and its component questions in identifying cases was assessed by calculating sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios and post-test probabilities.

Results

The age-standardised prevalence estimate of moderate–severe OSA was 9.1 % (12.4 % in men, 5.7 % in women). Sensitivity of the BQ in this population was 54 %, and specificity, 70 %. A combination of questions regarding snoring frequency and hypertension provided maximal post-test probability of OSA and greatest post-screen sample size.

Conclusions

Undiagnosed OSA is highly prevalent in the Western Australian general population. While the complete BQ is a sub-optimal screening instrument for the general population, snoring frequency or hypertension can be used to screen out moderate–severe OSA from general population samples with limited reduction in sample size. As there are few general population samples available for epidemiological or genetic studies of OSA and its associated phenotypes, these results may usefully inform future case–control studies.     

Sleep duration and body mass index in children and adolescents with and without obstructive sleep apnea

Purpose

The prevalence of pediatric obesity and short sleep duration has simultaneously increased in recent decades. Sleep plays a critical role in metabolic and endocrine regulation and insufficient sleep has been shown to be associated with changes in metabolism. Obesity, a major risk factor for obstructive sleep apnea (OSA), has been also associated with metabolic dysregulation. Despite this, no study investigating short sleep and obesity has addressed the potential confounder of OSA. The aim of this study was to investigate the association between short sleep duration and obesity in children with and without OSA.

Methods

In this retrospective study, 306 children who underwent polysomnography between January and December 2010 were included. A diagnosis of OSA was made if the apnea/hypopnea index on polysomnography is ≥1. Typical sleep times were obtained by parental report. Short sleep duration was defined as a reduction of >1 h from the minimum total sleep time (TST) recommended for age from the National Sleep Foundation (NSF).

Results

Overall, 32 % were obese, 39.5 % had short sleep duration, and 78 % had OSA. Children with OSA had a similar frequency of short sleep duration than those without (39.6 vs. 42.4 %, p?=?0.950). In children with short sleep duration, the odds ratio for obesity was 2.5 (95 % CI 1.3–4.9; p?=?0.009) compared to children with TST within normal limits even after accounting for the presence of OSA.

Conclusion

A parental history of total sleep duration of only 1 h less than recommended per age by the NSF is associated with a higher risk for obesity in children independently of the presence of OSA.     

The prevalence and correlates of habitual snoring during pregnancy

Purpose

Mounting evidence implicate habitual snoring, a prominent symptom of sleep-disordered breathing, as an important risk factor for adverse pregnancy outcomes including preeclampsia and gestational diabetes. Little, however, is known about the determinants of habitual snoring among pregnant women. We sought to assess its prevalence and to identify maternal characteristics associated with habitual snoring during pregnancy.

Methods

Pregnant women (N?=?1,303) receiving prenatal care provided information about habitual snoring before and during pregnancy in in-person interviews completed in early pregnancy. We calculated adjusted odds ratios (aOR) and 95 % confidence intervals (95 % CI) from multivariable models designed to identify factors associated with snoring during pregnancy.

Results

Approximately 7.3 % of pregnant women reported habitual snoring during early pregnancy. The odds of habitual snoring during pregnancy was strongly related with maternal reports of habitual snoring prior to the index pregnancy (aOR?=?24.32; 95 % CI, 14.30–41.51). Advanced maternal age (≥35 years) (aOR?=?2.02; 95 % CI, 1.11–3.68), history of pregestational diabetes (aOR?=?3.61; 95 % CI, 1.07–12.2), history of mood and anxiety disorders (aOR?=?1.81; 95 % CI, 1.02–3.20), and prepregnancy overweight (25–29.9 kg/m²) (aOR?=?2.31; 95 % CI, 1.41–3.77) and obesity (≥30 kg/m²) (aOR?=?2.81; 95 % CI, 1.44–5.48) status were statistically significant risk factors for habitual snoring during pregnancy. In addition, maternal smoking during pregnancy (aOR?=?2.70; 95 % CI, 1.17–6.26) was associated with habitual snoring during pregnancy.

Conclusions

Identification of risk factors for habitual snoring during pregnancy has important implications for developing strategies aimed at reducing the prevalence of sleep-disordered breathing, promoting improved sleep hygiene and improved pregnancy outcomes among reproductive-age women.     

Effects of obstructive sleep apnea severity on serum lipid levels in Greek children with snoring

Background

Although obstructive sleep apnea (OSA) is related to dyslipidemia in adults, limited data are available regarding its effects on serum lipids during childhood. Aim of this study was to assess the potential relationships between severity of OSA and cholesterol or triglyceride levels in a cohort of Greek children.

Methods

Data from children with snoring who underwent polysomnography and complete serum lipids measurements during a specified study period were analyzed retrospectively.

Results

Overall, obese children (n?=?261) had lower HDL cholesterol levels than non-obese subjects (n?=?113) (49.6?±?10.5 vs. 53.9?±?11.4 mg/dL; p?=?0.001) and higher triglyceride concentrations (69.8?±?32.2 vs. 63.2?±?27 mg/dL; p?=?0.041). Non-obese subjects with moderate-to-severe OSA did not differ in triglycerides, total, and LDL cholesterol concentrations but had lower HDL cholesterol, when compared to non-obese children with primary snoring/mild OSA (50.4?±?13.1 vs. 54.9?±?10.7 mg/dL; p?=?0.008). The risk for having low HDL cholesterol (??40 mg/dL) was threefold higher in non-obese subjects with moderate-to-severe OSA than in those with primary snoring/mild OSA, even after adjustment for age and gender [OR?=?3.44 (95% CI 1.44 to 8.24; p?=?0.006)]. Concentrations of serum lipids in obese children were not associated with severity of OSA. HDL cholesterol was 48.5?±?8.7 mg/dL in subjects with moderate-to-severe OSA and 50.0?±?11.1 mg/dL in children with primary snoring/mild OSA (p?=?0.519).

Conclusions

HDL cholesterol levels are inversely related to severity of OSA in non-obese children with snoring.     

Self-reported obstructive sleep apnea,simple snoring,and various markers of sleep-disordered breathing as predictors of cardiovascular risk

Purpose

Our objective was to investigate whether self-reported obstructive sleep apnea (OSA), simple snoring, and various markers of sleep-disordered breathing (SDB) are associated with cardiovascular risk.

Methods

We examined a representative nationwide cohort of 5177 Finnish adults aged ≥30 years. The participants underwent measurement of traditional cardiovascular risk factors and answered SDB-related questions derived from the Basic Nordic Sleep Questionnaire, which were used to operationalize self-reported OSA. The primary end point was incidence of a cardiovascular event (cardiovascular mortality, non-fatal myocardial infarction, non-fatal stroke, hospitalization for heart failure, or coronary interventions).

Results

During a median follow-up of 11.2 years and 52,910 person-years of follow-up, 634 participants suffered a cardiovascular event. In multivariable-adjusted Cox models, self-reported OSA (hazard ratio [HR] 1.34; 95 % confidence interval [CI] 1.04–1.73; p?=?0.03) was an independent predictor of cardiovascular events. Self-reported simple snoring by itself was not associated with future cardiovascular events (HR 0.88 versus non-snorers, 95 % CI 0.75–1.04, p?=?0.15). However, among snorers (n?=?3152), frequent breathing cessations (HR 2.19, 95 % CI 1.26–3.81, p?=?0.006) and very loud and irregular snoring (HR 1.82, 95 % CI 1.31–2.54, p?<?0.001) were associated with cardiovascular risk.

Conclusions

Self-reported OSA and SDB-related snoring variables are associated with cardiovascular risk, whereas simple snoring is not. In clinical practice and in surveys, questions concerning only habitual snoring should be amended with questions focusing on respiratory pauses and snoring stertorousness, which can be used to estimate the risk of OSA and cardiovascular events.

     

Severe obstructive sleep apnea increases mortality in patients with ischemic heart disease and myocardial injury

Objectives

We hypothesized that obstructive sleep apnea (OSA) has a dose-dependent impact on mortality in those with ischemic heart disease or previous myocardial injury.

Methods

We performed a retrospective cohort study of 281 consecutive OSA patients with a history of myocardial injury as determined by elevated troponin levels or with known existing ischemic heart disease. We compared survival between those with severe OSA [apnea–hypopnea index (AHI) ≥30] and those with mild to moderate OSA (AHI >5 and <30).

Results

Of the 281 patients (mean age 65 years, mean BMI 34, 98% male, 58% with diabetes), 151 patients had mild-moderate OSA and 130 had severe OSA. During a mean follow-up of 4.1 years, there were significantly greater deaths in the severe OSA group compared to the mild-moderate OSA group [53 deaths (41%) vs. 44 deaths (29%), respectively, p?=?0.04]. The adjusted hazard ratio for mortality with severe OSA was 1.72 (95% confidence interval 1.01–2.91, p?=?0.04).

Conclusions

The severity of obstructive sleep apnea is associated with increased risk of death, and risk stratification based on OSA severity is relevant even in the diseased cardiac patient.     

Clinical and polysomnographic findings of patients with large goiters

Introduction

Goiters cause a series of compressive symptoms, including dyspnea and dysphagia. There have been reports of the coexistence of this syndrome with obstructive sleep apnea (OSA). The objective of this study was to evaluate the prevalence of OSA in a group of patients with goiters.

Methods

Twenty-four patients with a mean age of 52.7?±?12.7 years, including five males (20.8 %) and 19 (79.2 %) females, who were diagnosed with euthyroid goiters with volumes exceeding 100 ml were consecutively selected. The protocol consisted of sleep questionnaires, physical examinations, and baseline polysomnography measurements. Patients were divided into two groups, OSA and NOSA (no OSA), and all findings were compared between the two groups.

Results

Of the studied patients, 70.8 % had OSA (p?=?0.004). Regarding clinical parameters, age (p?=?0.001), Epworth Sleepiness Scale scores (p?=?0.039) and complaints of habitual snoring (p?<?0.001) had higher values in the OSA group. Regarding physical examination parameters, body mass index (p?=?0.012), neck circumference (p?=?0.009) and the presence of tracheal compression (p?=?0.021) had higher values in the OSA group. The polysomnographic parameters that were significantly different between the two groups were the greater apnea and hypopnea index per hour of sleep (p?<?0.001) and the lower minimum oxyhemoglobin saturation in the OSA group (p?=?0.011).

Conclusions

There is a high prevalence of OSA in patients with goiters. The main findings that were associated with the presence of OSA are known clinical predictors of OSA and the presence of tracheal compression.     

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.     

Postoperative complications in obstructive sleep apnea

Study objectives

This study was conducted to determine whether postoperative complications are increased in patients with obstructive sleep apnea (OSA) and to study the impact of the severity of OSA and preoperative use of continuous positive airway pressure (CPAP) on the postoperative outcome.

Design and setting

This study is retrospective in nature and was undertaken at the VA Medical Center.

Participants and methods

Three hundred seventy patients who had undergone both a major surgical procedure and a sleep study from 2000 to 2010 were identified. Patients were divided into four groups: OSA negative (apnea–hypopnea index (AHI)?<?5/h), OSA positive; mild: AHI 5 to <15/h; moderate: AHI 15 to <30/h; and severe: AHI?≥?30/h. No intervention was made during the course of the study. Postoperative complications namely respiratory, cardiac, neurological, and unplanned intensive care unit transfers were collected.

Results

There were 284 (76.8 %) patients having OSA and 86 (23.2 %) without OSA. The overall incidence of total complications was significantly higher in the OSA patients compared with the control patients (48.9 vs. 31.4 %; odds ratio 2.09, 95 % CI 1.25–3.49). There was no significant difference in total complications between those using and not using CPAP prior to hospitalization. Patients with sleep apnea had a higher incidence of respiratory complications compared to patients without sleep apnea (40.4 vs. 23.2 %; odds ratio 2.24, 95 % CI 1.29–3.90). There was no significant difference in major cardiac complications in the OSA patients compared with the control patients (13.0 vs. 9.3 %; odds ratio 1.46, 95 % CI 0.65–3.26).

Conclusion

OSA is associated with a significantly increased rate of postoperative complications.     

Factors Associated with Systemic Hypertension in Asthma

Purpose

Asthmatics have unique characteristics that may influence cardiovascular morbidity. We tested the association of lower airway caliber, obstructive sleep apnea (OSA), and other asthma-related factors, with systemic hypertension (HTN).

Methods

Asthma individuals at specialty clinics completed the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ). Medical records were reviewed for diagnosed HTN, OSA and comorbidities, spirometry, and current medications. FEV₁% predicted was categorized as ≥80 (reference), 70–79, 60–69, and <60. SA-SDQ ≥36 for men and ≥32 for women defined high OSA risk.

Results

Among 812 asthmatics (mean age ± standard deviation: 46 ± 14 years), HTN was diagnosed in 191 (24 %), OSA in 65 (8 %), and OSA or high OSA risk (combined OSA variable) in 239 (29 %). HTN was more prevalent in lower FEV₁% categories (p < 0.0001), in subjects with OSA, and those with combined OSA variable (55 vs. 21 % and 46 vs. 14 %, respectively, both p < 0.0001). With adjustment for covariates, associations with HTN remained significant for some FEV₁% categories (70–79 % odds ratio = 1.60 [95 % CI 0.90–2.87]; 60–69 % 2.73 [1.28–5.79]; <60 % 0.96 [0.43–2.14]), and for OSA (2.20 [1.16–4.19]). The combined OSA variable in comparison with OSA alone demonstrated a stronger association with HTN (3.17 [1.99–5.04]) in a reiteration of this model. Inhaled corticosteroids (ICS) at lowest doses, in comparison to no ICS use had an independent “protective” association with HTN (0.44 [0.22–0.90]).

Conclusions

In this young population, worse lower airways obstruction and OSA were associated with HTN. In contrast, lower ICS doses attenuated likelihood for HTN. Adequate control of airway inflammation at appropriate ICS doses, and screening for OSA may reduce the burden of HTN in asthma.     

Polygraphy vs. polysomnography: missing osas in symptomatic snorers—a reminder for clinicians

Purposes

The purposes of this study are to investigate the usefulness of polygraphy (PG) in diagnosing obstructive sleep apnea (OSA) in sleepy/tired snorers compared to polysomnography (PSG) and, further, to search for suspected respiratory arousals in the PG.

Methods

One hundred eighty-seven adults suffering from sleepiness/tiredness and snoring had undergone ambulant PG and were considered to be normal, using American Academy of Sleep Medicine’s 2007 hypopnea criteria A. After approximately 7 months, in-lab PSG was performed using hypopnea criteria B, where arousals are also recognized. Validated questionnaires (Hospital Anxiety and Depression Scale, self-rated general health) were answered. In a subgroup, the sensitivity and specificity were calculated for flow limitation index (FLI) and flattening index (FlatI) in PG compared with the respiratory distress index (RDI) in PSG.

Results

Despite the normal PG, at PSG, the median RDI was 11.0 (range, 0–89.1). One hundred sixty-eight out of one hundred seventy-eight (90 %) were found to have at least mild OSA and 119/187 (64 %) with moderate–severe OSA according to the RDI values. The sensitivity and specificity were low (<70 %) for FLI and FlatI. Forty-nine percent of the patients rated anxiety at borderline or pathological levels, 35 % rated corresponding depression levels, and 45 % rated poor or fair general health.

Conclusions

PG was insufficient to rule out OSA when the respiratory events were mainly associated with arousals. Almost half of these patients experience low general health and psychiatric problems. We recommend a full-night PSG when PG is “normal”, and patients have symptoms of snoring and sleepiness/tiredness.     

Levels of neuroglobin in serum and neurocognitive impairments in Chinese patients with obstructive sleep apnea

Purpose

The impact of different severities of obstructive sleep apnea (OSA) on cognition has not well been documented. Neuroglobin, a recently discovered vertebrate protein, shows a neuroprotective function to modulate hypoxic–ischemic brain injury. This study investigated the cognitive function of patients with varying OSA severities and intended to explore the relationship between levels of neuroglobin in serum and cognitive deficits of OSA.

Methods

Sixty Chinese adults aged 18–59 years old were enrolled and categorized into four groups based on apnea–hypopnea index (AHI): primary snoring (n?=?7), mild (n?=?13), moderate (n?=?20), and severe (n?=?20) OSA groups. Computer-based neurocognitive tests (including calculation, memory, and attention) and Epworth sleepiness scale were administered before polysomnographic monitoring, and blood sample was taken the next morning. Concentrations of serum neuroglobin were measured using ELISA.

Results

No significant difference was observed in cognitive function regardless of OSA severities, but patients with moderate and severe OSA presented significantly more sleepiness than patients with primary snoring and mild OSA. Memory significantly correlated with time spent with oxygen saturation below 90 % during nighttime (T?<?90 %), as well as oxygen desaturation index, AHI, or NREM sleep. Calculation correlated significantly with sleepiness and respiratory arousal index. Levels of neuroglobin in serum of patients with varying OSA severities were significant elevated than that of patients with primary snoring. No relationship was found between the neurobehavioral ability index of neurocognitive tests and serum neuroglobin concentrations after controlling for gender, age, and BMI, whereas the unique association between levels of neuroglobin in serum and the scores of auditory digit span test was noted.

Conclusions

Our findings suggest that different neurocognitive domains might specifically correlate to either sleepiness or hypoxemia. Changes of concentrations of neuroglobin in serum may possibly be used as an indicator to monitor the brain damage of OSA. Further investigations are needed to explore the relationship between regulation of neuroglobin in serum and severity of brain damage in OSA.     

The prevalence and associated risk factors of sleep disorder-related symptoms in pregnant women in China

Purpose

The sleep disorder in pregnant women remains unfamiliar to perinatal care providers, resulting in lack of appropriate care. This study was designed to investigate the prevalence of sleep disorder-related symptoms in pregnant women and to identify the associated risk factors.

Methods

Married pregnant women were enrolled from their first trimester and followed up until delivery. Nonpregnant married healthy women were selected as controls. A survey questionnaire was administered to each of them.

Results

We successfully performed a survey to 1,993 pregnant women and 598 nonpregnant women. The overall prevalence of sleep disorder-related symptoms in pregnant women was significantly higher than the controls (56.1 vs. 29.9 %, P?<?0.05). There was higher prevalence of snoring (30.2 %), observed sleep apnea (1.1 %), mouth breathing (23.7 %), nocturnal arousal (46.5 %), insomnia (35.1 %), and daytime sleepiness (52.6 %) in pregnant women. There were no significant differences of the prevalence of bruxism (7.0 vs. 6.7 %), sleep talking (8.1 vs. 7.2 %), and sleep walking (0.4 vs. 0.2 %) between the two groups (P?>?0.05). Nocturnal sleep time (8.0?±?1.3 h) was less in the third trimester compared with the nonpregnant women (8.2?±?1.1 h) (P?<?0.05). Smoking (OR?=?3.39), drinking (OR?=?2.40), allergic rhinitis/asthma (OR?=?1.71), an obvious difference in neck circumference (OR?=?1.11), and waistline (OR?=?1.07) changes between the first and third trimesters were the risk factors for sleep disorder-related problems.

Conclusions

There is a high prevalence of sleep disorder-related symptoms in pregnant women. Our data may provide a baseline for prevention and treatment of sleep disturbances in pregnant women.     

Surface cephalometric and anthropometric variables in OSA patients: statistical models for the OSA phenotype

Study objective

We used statistical modelling to probe the contributions of anthropometric and surface cephalometric variables to the OSA phenotype.

Design

The design is prospective cohort study.

Setting

The setting is community-based and sleep disorder laboratory.

Patients or participants

Study #1—Model development study: 147 healthy asymptomatic volunteers (62.6 % Caucasian; age, 18–76 years; 81 females; median multivariable apnea prediction index?=?0.15) and 140 diagnosed OSA patients (84.3 % Caucasian; age, 18–83 years; 41 females; polysomnography [PSG] determined apnea–hypopnea index >10 events/h). Study #2—Model test study: 345 clinic patients (age, 18–86 years; 129 females) undergoing PSG for diagnosis of OSA.

Intervention

We measured 10 anthropometric and 34 surface cephalometric dimensions (calipers) and calculated mandibular enclosure volumes for study #1 and recorded age and neck circumference for study #2. Statistical modelling included principal component (PC), logistic regression, and receiver–operator curve analyses.

Measurements and results

Model development study: A regression model incorporating three identified PC predicted OSA with 88 % sensitivity and specificity. However, a simplified model based on age and NC alone was equally effective (87 % sensitivity and specificity). Model test study: The simplified model predicted OSA with high sensitivity (93 %) but poor specificity (21 %).

Conclusion

We conclude that in our clinic-based cohort, craniofacial bony and soft tissue structures (excluding neck anatomy) do not play a substantial role in distinguishing patients with OSA from those without. This may be because craniofacial anatomy does not contribute greatly to the pathogenesis of OSA in this group or because referral bias has created a relatively homogeneous phenotypic population.     

Nocturnal intermittent hypoxia and the development of type 2 diabetes: the Circulatory Risk in Communities Study (CIRCS)

Aims/hypothesis

Although the associations between obstructive sleep apnoea and type 2 diabetes mellitus have been reported in cross-sectional design studies, findings on the prospective association between the two conditions are limited. We examined prospectively the association between nocturnal intermittent hypoxia as a surrogate marker of obstructive sleep apnoea and risk of type 2 diabetes.

Methods

A total of 4,398 community residents aged 40 to 69 years who had participated in sleep investigation studies between 2001 and 2005 were enrolled. Nocturnal intermittent hypoxia was assessed by pulse-oximetry and defined by the number of oxygen desaturation measurements ≤3% per h, with five to <15 per h corresponding to mild and 15 events or more per h corresponding to moderate-to-severe nocturnal intermittent hypoxia, respectively. The development of type 2 diabetes was defined by: (1) fasting serum glucose ≥7.00 mmol/l (126 mg/dl); (2) non-fasting serum glucose ≥11.1 mmol/l (200 mg/dl); and/or (3) initiation of glucose-lowering medication or insulin therapy. Multivariable model accounted for age, sex, BMI, smoking status, current alcohol intake, community, borderline type 2 diabetes, habitual snoring, excessive daytime sleepiness, sleep duration and (for women) menopausal status.

Results

By the end of 2007, 92.2% of participants had been followed up (median follow-up duration [interquartile range] 3.0 [2.9–4.0] years) and 210 persons identified as having developed diabetes. The multivariable-adjusted hazard ratio (95% CI) for developing type 2 diabetes was 1.26 (0.91–1.76) among those with mild nocturnal intermittent hypoxia and 1.69 (1.04–2.76) among those with moderate-to-severe nocturnal intermittent hypoxia (p?=?0.03 for trend).

Conclusions/interpretation

Nocturnal intermittent hypoxia was associated with increased risk of developing type 2 diabetes among middle-aged Japanese.     

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.     

Home-based diagnosis of obstructive sleep apnea by polysomnography type 2: accuracy,reliability, and feasibility

Purpose

Despite being used in large cohort studies, role of polysomnography (PSG) type 2 is still controversy. This study was aimed to determine its accuracy, reliability, and feasibility in diagnosis of obstructive sleep apnea (OSA) compared to gold standard.

Methods

Adult patients with stable medical conditions who complained of snoring or excessive sleepiness and lived around Bangkok were recruited from a sleep clinic. All were asked to fill questionnaires and have PSG done in laboratory (in-Lab PSG) and at home (Home PSG) on separate nights within 2–4 weeks interval.

Results

Eighty-six patients, 48 males and 38 females, were included. Mean of total sleep time, sleep efficiency, and stage R were significantly greater in Home PSG than in-Lab PSG (p?p?=?0.04), but with excellent reliability, intra-class correlation coefficients of 0.96 (95 % CI; 0.93–0.97), and good agreements (κ?=?0.59–0.70) between both tests. The sensitivity, specificity, and accuracy of Home PSG at cut-off point of AHI ≥5, were 0.97, 0.56, and 0.85, respectively, and at AHI ≥15 were 0.95, 0.76, and 0.85, respectively. Sixty-four patients (74.4 %) preferred home-PSG but four patients (4.7 %) needed repeated tests due to significant data loss.

Conclusions

This is the first report in Asia demonstrating that home-based diagnosis of OSA by PSG type 2 was feasible performing with good reliability, high accuracy, and a low failure rate. However, further studies focusing on its cost-effectiveness are required.     

Mandibular tori size is related to obstructive sleep apnea and treatment success with an oral appliance

Purpose

Obstructive sleep apnea (OSA) is a common disorder characterized by repetitive upper airway obstruction during sleep. We aimed to investigate whether mandibular tori, exostoses that appear on the lingual surface of the lower jaw, are related to OSA and the effect of an oral appliance (OA) in OSA patients.

Methods

Six hundred snoring patients with a mean age of 52 years (range 23–75 years) and a mean respiratory disturbance index (RDI) of 15 (range 0–76), who were consecutively referred for OA treatment, were included. The size of the tori was measured on plaster casts with a digital sliding caliper.

Results

Twenty-seven percent of the patients had mandibular tori, with a similar prevalence in snorers and patients with mild, moderate and severe OSA. Tori size differed between severity groups. Thick tori (≥2.9 mm) were associated with an RDI of <30, odds ratio (OR) 4.7 (p?=?0.01), adjusted for age, gender and body mass index (BMI; kg/m²). Complete treatment response with OA was related to thick tori, OR?=?2.5 (p?=?0.02), adjusted for disease severity, age, gender, BMI (kg/m²), weight changes (kg) and mandibular repositioning.

Conclusions

Patients with milder disease are more likely to have larger tori than patients with severe OSA. Treatment success with an OA occurs more frequently in patients with larger tori than in patients with no tori or small tori.     

Sleep disorders in pregnancy and their association with pregnancy outcomes: a prospective observational study

Purpose

Sleep disturbances such as insomnia, nocturnal awakenings, restless legs syndrome, habitual snoring, and excessive daytime sleepiness are frequent during pregnancy, and these have been linked to adverse maternal and fetal outcomes.

Methods

A prospective observational study was performed in high-risk Indian pregnant women. We used modified Berlin questionnaire (MBQ), Pittsburgh sleep quality index (PSQI), International Restless Legs Syndrome Study Group 2011 criteria, and Epworth sleepiness scale to diagnose various sleep disorders, such as symptomatic OSA, poor sleep quality and insomnia, RLS, and excessive daytime sleepiness, respectively, in successive trimesters of pregnancy. Outcome variables of interest were development of gestational hypertension (GH), gestational diabetes mellitus (GDM), and cesarean delivery (CS); the Apgar scores; and low birth weight (LBW). The relationship between sleep disorders and outcomes was explored using logistic regression analysis.

Results

Outcome data were obtained in 209 deliveries. As compared to nonsnorers, women who reported snoring once, twice, and thrice or more had odds ratios for developing GH—4.0 (95 % CI 1.3–11.9), 1.5 (95 % CI 0.5–4.5), and 2.9 (95 % CI 1.0–8.2) and for undergoing CS—5.3 (95 % CI 1.7–16.3), 4.9 (95 % CI 1.8–13.1), and 5.1 (95 % CI 1.9–14.9), respectively. Pregnant women who were persistently positive on MBQ had increased odds for GH and CS.

Conclusions

Snoring and high-risk MBQ in pregnant women are strong risk factors for GH and CS. In view of the significant morbidity and health care costs, simple screening of pregnant women with questionnaires such as MBQ may have clinical utility.