A survey screen for prediction of apnea

Socioeconomic status, occupational characteristics, and sleep duration in African/Caribbean immigrants and US White health care workers

STUDY OBJECTIVES

o advance our understanding of the interplay of socioeconomic factors, occupational exposures, and race/ethnicity as they relate to sleep duration. We hypothesize that non Hispanic African/Caribbean immigrant employees in long term health care have shorter sleep duration than non Hispanic white employees, and that low education, low income, and occupational exposures including night work and job strain account for some of the African/Caribbean immigrant-white difference in sleep duration.

DESIGN

Cross sectional

SETTING

Four extended care facilities in Massachusetts, United States

PARTICIPANTS

340 employees in extended care facilities

MEASUREMENTS AND RESULTS

Sleep duration was assessed with wrist actigraphy for a mean of 6.3 days. In multivariable regression modeling controlling for gender and age, African/Caribbean immigrants slept 64.4 fewer minutes (95% CI: -81.0, -47.9) per night than white participants; additional control for education and income reduced the racial gap to 50.9 minutes (-69.2, -32.5); additional control for the occupational factors of hours worked per week and working the night shift reduced the racial gap to 37.7 minutes (-57.8, -17.6).

CONCLUSIONS

his study provides support for the hypothesis that socioeconomic and occupational characteristics explain some of the African/ Caribbean immigrant-white difference in sleep duration in the United States, especially among health care workers.

The relationship between the predictors of obstructive sleep apnea and difficult intubation

Background

The study was performed in order to determine the risk factors for difficult tracheal intubation in obstructive sleep apnea patients.

Methods

For 115 male patients with obstructive sleep apnea syndrome and who were undergoing palatal muscle resection (PMR), we investigated the correlation between their age, height, weight, body mass index (BMI), their Epworth Sleepiness Scale (ESS), their apnea-hypopnea index (AHI), their neck circumference and the difficulty of tracheal intubation.

Results

The factors significantly related to difficult tracheal intubation in obstructive sleep apnea patients were a high AHI and a large neck circumference. There was no significant correlation between weight, BMI, arterial hypertension, ESS and difficult tracheal intubation in obstructive sleep apnea patients.

Conclusions

In this study, a high AHI and a large neck circumference can predict difficult tracheal intubation in obstructive sleep apnea patients.

Sleep symptoms predict the development of the metabolic syndrome

BACKGROUND

Sleep complaints are highly prevalent and associated with cardiovascular disease (CVD) morbidity and mortality. This is the first prospective study to report the association between commonly reported sleep symptoms and the development of the metabolic syndrome, a key CVD risk factor.

METHODS

Participants were from the community-based Heart Strategies Concentrating on Risk Evaluation study. The sample was comprised of 812 participants (36% African American; 67% female) who were free of metabolic syndrome at baseline, had completed a baseline sleep questionnaire, and had metabolic syndrome evaluated 3 years after baseline. Apnea-hypopnea index (AHI) was measured cross-sectionally using a portable monitor in a subset of 290 participants. Logistic regression examined the risk of developing metabolic syndrome and its components according to individual sleep symptoms and insomnia syndrome.

RESULTS

Specific symptoms of insomnia (difficulty falling asleep [DFA] and "unrefreshing" sleep), but not a syndromal definition of insomnia, were significant predictors of the development of metabolic syndrome. Loud snoring more than doubled the risk of developing the metabolic syndrome and also predicted specific metabolic abnormalities (hyperglycemia and low high-density lipoprotein cholesterol). With further adjustment for AHI or the number of metabolic abnormalities at baseline, loud snoring remained a significant predictor of metabolic syndrome, whereas DFA and unrefreshing sleep were reduced to marginal significance.

CONCLUSION

Difficulty falling asleep, unrefreshing sleep, and, particularly, loud snoring, predicted the development of metabolic syndrome in community adults. Evaluating sleep symptoms can help identify individuals at risk for developing metabolic syndrome.

Noninferiority of functional outcome in ambulatory management of obstructive sleep apnea

RATIONALE

Home portable monitor testing is increasingly being used to diagnose patients with obstructive sleep apnea (OSA) and to initiate them on continuous positive airway pressure (CPAP) treatment.

OBJECTIVES

To compare functional outcome and treatment adherence in patients who receive ambulatory versus in-laboratory testing for OSA.

METHODS

Veterans with suspected OSA were randomized to either home testing or standard in-laboratory testing. Home testing consisted of a type 3 portable monitor recording followed by at least three nights using an automatically adjusting positive airway pressure apparatus. Participants diagnosed with OSA were treated with CPAP for 3 months.

MEASUREMENTS AND MAIN RESULTS

We measured the change in Functional Outcomes of Sleep Questionnaire score, with an a priori noninferiority delta of -1, and the mean daily hours of objectively measured CPAP adherence, with an a priori noninferiority delta of -0.75 hour/day. Of the 296 subjects enrolled, 260 (88%) were diagnosed with OSA, and 213 (75%) were initiated on CPAP. Mean ± SD functional outcome score improved 1.74 ± 2.81 in the home group (P < 0.001) and 1.85 ± 2.46 in the in-laboratory group (P < 0.0001). The lower bound of the one-sided 95% noninferiority confidence interval was -0.54. Mean ± SD hours of daily CPAP adherence were 3.5 ± 2.5 hours/day in the home group and 2.9 ± 2.3 hours/day in the in-laboratory group (P = 0.08). The lower bound of the one-sided 95% noninferiority confidence interval was 0.03.

CONCLUSIONS

Functional outcome and treatment adherence in patients evaluated according to a home testing algorithm is not clinically inferior to that in patients receiving standard in-laboratory polysomnography.

Testosterone and modifiable risk factors associated with diabetes in men

OBJECTIVE

The role of endogenous testosterone in the pathogenesis of type 2 diabetes mellitus remains vague. We investigated whether associations between endogenous testosterone and diabetes prevalence in men could be partially explained by modifiable risk factors.

STUDY DESIGN

A random population-based cross-sectional study of 1195 men aged 35-80 years living in the north-west regions of Adelaide, Australia. Data collections occurred between 2002 and 2005, and response rate was 45.1%.

MATERIALS AND METHODS

Diabetes (non-specific) was classified by either: (1) self-report for doctor diagnosis of diabetes; (2) prescription medication for diabetes; (3) fasting plasma glucose ≥ 7 mmol/L; or (4) glycosylated haemoglobin ≥ 6.2%. Logistic regressions were used to estimate odds ratios (OR [with 95% confidence intervals]) for diabetes, with stepwise adjustments for demographic, lifestyle, and clinical factors.

RESULTS

Diabetes prevalence was positively associated with age groups 45-54 years (2.8 [1.4, 5.8]), 55-64 years (3.9 [1.9, 8.3]) and ≥ 65 years (4.0 [1.8, 8.9]), lowest income group (1.8 [1.0, 3.4]), ex-smoker (1.8 [1.2, 2.9]), lowest (3.2 [1.9, 5.5]) and middle (1.9 [1.1, 3.4]) alcohol tertiles, cardiovascular disease (1.9 [1.2, 2.8]), metabolic syndrome (4.0 [2.6, 6.1]), and lowest plasma total testosterone tertile (1.8 [1.1, 3.0]), but negatively associated with middle (0.5 [0.3, 0.8]) and highest (0.4 [0.3, 0.7]) sugar intake tertiles, arthritis (0.6 [0.3, 1.0]), and elevated LDL cholesterol (0.5 [0.3, 0.8]); ORs showed an inverted 'U' shape for middle and highest voiding lower urinary tract symptoms tertiles. Body composition, muscle strength, and cardio-metabolic factors partially explained the association between low plasma total testosterone and diabetes.

CONCLUSIONS

Plasma total testosterone was inversely and independently associated with diabetes prevalence, that might have been partially explained by several modifiable risk factors.

Excessive daytime sleepiness among Japanese public transportation drivers engaged in shiftwork

OBJECTIVE

To explore the actual condition of sleep disorders underlying subjective excessive daytime sleepiness (EDS) among train and bus drivers engaged in shiftwork.

METHODS

This study targeted 3109 public transportation drivers. Clinical diagnoses were made based on 147 drivers who claimed to have subjective EDS, and 285 drivers who were judged to have obstructive sleep apnea syndrome (OSAS), based on the screening process.

RESULTS

Among these subjects, the prevalence of OSAS was 3.7% and that of shiftwork disorder (SWD) was 1.5%. SWD was common among drivers who had EDS (32.7% of drivers with EDS), and their EDS severity was higher than that of OSAS drivers. The drivers with SWD were mostly young and neither obese nor hypertensive.

CONCLUSIONS

Encouraging awareness of SWD and OSAS could be necessary to prevent sleepiness-related accidents.

Anthropometry in the prediction of sleep disordered breathing in HIV-positive and HIV-negative men

BACKGROUND

Body mass index (BMI), waist circumference (WC) and neck circumference (NC) are important screening tools for sleep disordered breathing (SDB); however, the utility of anthropometry for this purpose has not been evaluated among HIV-positive patients.

METHODS

HIV-negative men (n=60), HIV-positive men receiving highly active antiretroviral therapy (HIV-positive/HAART; n=58) and HIV-positive men not receiving HAART (HIV-positive/no HAART; n=41) from the Multicenter AIDS Cohort Study underwent a nocturnal sleep study and anthropomorphic assessment. Moderate-severe SDB was defined as an apnea/hypopnea event rate > or =15 episodes/h. Receiver operating characteristic (ROC) curves were used to compare the ability of different anthropometric measurements to predict SDB within each group.

RESULTS

Moderate-severe SDB was found in 48% of men (HIV-negative [57%], HIV-positive/HAART [41%] and HIV-positive/no HAART [44%]). The performance of BMI, WC and NC to predict SDB was excellent among the HIV-negative men (ROC areas under the curve [AUCs] 0.83, 0.88 and 0.88, respectively) and fair among the HIV-positive/HAART group (AUC 0.71, 0.77 and 0.77, respectively). By contrast, these measurements had no predictive value in the HIV-positive/no HAART group (AUC 0.43, 0.41 and 0.45, respectively). Moreover, in the HIV-positive/no HAART group, moderate-severe SDB was independently associated with serum C-reactive protein > or =3.0 mg/l (odds ratio 6.9; P=0.04) and HIV RNA>10,000 copies/ml (odds ratio 7.1; P=0.05).

CONCLUSIONS

BMI, WC and NC had a better predictive value for moderate-severe SDB in HIV-positive men compared with HIV-positive [corrected] men, and had no value among HIV-positive/no HAART men. Among this latter group, systemic inflammation might contribute to the pathogenesis of SDB.

Imagery rehearsal for posttraumatic nightmares: a randomized controlled trial

One hundred twenty-four male Vietnam War veterans with chronic, severe posttraumatic stress disorder (PTSD) were randomly assigned to imagery rehearsal (n = 61) or a credible active comparison condition (n = 63) for the treatment of combat-related nightmares. There was pre-post change in overall sleep quality and PTSD symptoms for both groups, but not in nightmare frequency. Intent-to-treat analyses showed that veterans who received imagery rehearsal had not improved significantly more than veterans in the comparison condition for the primary outcomes (nightmare frequency and sleep quality), or for a number of secondary outcomes, including PTSD. Six sessions of imagery rehearsal delivered in group format did not produce substantive improvement in Vietnam War veterans with chronic, severe PTSD. Possible explanations for findings are discussed.

Obstructive sleep apnea: role in the risk and severity of diabetes

Obstructive sleep apnea (OSA) is a treatable sleep disorder that is pervasive among overweight and obese individuals. Current evidence supports a robust association between OSA and insulin resistance, glucose intolerance and the risk of type 2 diabetes, independent of obesity. Up to 83% of patients with type 2 diabetes suffer from unrecognized OSA and increasing severity of OSA is independently associated with poorer glucose control. Evidence from animal and human models that mimic OSA supports a potential causal role for OSA in altered glucose metabolism. Robust prospective and randomized clinical trials are still needed to test the hypothesis that effective treatment of OSA may prevent the development of type 2 diabetes and its complications, or reduce its severity. Type 2 diabetes is occurring at alarming rates worldwide and despite available treatment options, the economic and public health burden of this epidemic remains enormous. OSA might represent a novel, modifiable risk factor for the development of prediabetes and type 2 diabetes.

Obstructive sleep apnea syndrome: natural history, diagnosis, and emerging treatment options

Sleep apnea is an entity characterized by repetitive upper airway obstruction resulting in nocturnal hypoxia and sleep fragmentation. It is estimated that 2%-4% of the middle-aged population has sleep apnea with a predilection in men relative to women. Risk factors of sleep apnea include obesity, gender, age, menopause, familial factors, craniofacial abnormalities, and alcohol. Sleep apnea has been increasingly recognized as a major health burden associated with hypertension and increased risk of cardiovascular disease and death. Increased airway collapsibility and derangement in ventilatory control responses are the major pathological features of this disorder. Polysomnography (PSG) is the gold-standard method for diagnosis of sleep apnea and assessment of sleep apnea severity; however, portable sleep monitoring has a diagnostic role in the setting of high pretest probability sleep apnea in the absence of significant comorbidity. Positive pressure therapy is the mainstay therapy of sleep apnea. Other treatment modalities, such as upper airway surgery or oral appliances, may be used for the treatment of sleep apnea in select cases. In this review, we focus on describing the sleep apnea definition, risk factor profile, underlying pathophysiologic mechanisms, associated adverse consequences, diagnostic modalities, and treatment strategies.

The utility of single-channel nasal airflow pressure transducer in the diagnosis of OSA at home

RATIONALE

Given the high prevalence of obstructive sleep apnea (OSA) and the demand on polysomnography (PSG), there is a need for low cost accurate simple diagnostic modalities that can be easily deployed in primary care to improve access to diagnosis.

STUDY OBJECTIVES

The aim was to examine the utility of single-channel nasal airflow monitoring using a pressure transducer at home in patients with suspected OSA.

DESIGN

Cross-sectional study

SETTING

Laboratory and home

PARTICIPANTS

The study was conducted in two populations. Consecutive patients with suspected OSA were recruited from the sleep disorders clinic at a tertiary referral center and from 6 local metropolitan primary care centers.

INTERVENTIONS

All patients answered questionnaires and had laboratory PSG. Nasal airflow was monitored for 3 consecutive nights at home in random order either before or after PSG.

RESULTS

Atotal of 193 patients participated (105 sleep clinic patients and 88 from primary care). The mean bias PSG apnea hypopnea index (AHI) minus nasal flow respiratory disturbance index (NF RDI) was -4.9 events per hour with limits of agreement (2 SD) of 27.8. NF RDI monitored over 3 nights had high accuracy for diagnosing both severe OSA (defined as PSG AHI > 30 events per hour) with area under the receiver operating characteristic curve (AUC) 0.92 (95% confidence interval (CI) 0.88-0.96) and any OSA (PSG AHI > 5), AUC 0.87 (95% CI 0.80-0.94).

CONCLUSIONS

Single-channel nasal airflow can be implemented as an accurate diagnostic tool for OSA at home in both primary care and sleep clinic populations.

Sleep apnea, daytime somnolence, and idiopathic dizziness--a novel association

OBJECTIVES/HYPOTHESIS

To determine if an association exists between sleep apnea, daytime somnolence, and chronic idiopathic dizziness.

STUDY DESIGN

Case-control study of new patients presenting to a tertiary neuro-otologic practice. A total of 46 subjects with idiopathic dizziness (ID), 20 positive controls with dizziness (benign paroxysmal positional vertigo [BPV]), and 69 negative controls with hearing loss (HL) but no dizziness were enrolled.

METHODS

Participants who were patients diagnosed with the above conditions and who met all other inclusion criteria completed a sleep questionnaire and had a complete physical exam and investigations to establish or exclude a neuro-otologic diagnosis. They were subsequently evaluated for risk of symptomatic sleep disturbance based on the Epworth Sleepiness Scale (ESS), the Berlin Questionnaire, and the Multivariable Apnea Risk Index (MAP). Statistical analysis was carried out using SPSS (SPSS Inc., Chicago, IL).

RESULTS

There was no significant demographic difference among the groups in terms of age, sex, body mass index, neck size, alcohol consumption, or smoking. Using a cutoff of both 10 and 12 on the ESS, the ID were more likely to have significant daytime somnolence than the HL group, with a likelihood ratio (LR) of 7.8 for the ESS 12 score (P = .021) and 7.1 for the ESS 10 score (P = .029). Using the MAP score, a statistically significant difference between the ID group and both the BPV group (LR 3.99, P = .046) and the HL group (LR 5.46, P = .019) was found.

CONCLUSIONS

This study suggests that a previously undescribed link between idiopathic dizziness, daytime somnolence, and sleep apnea might exist. Prospective investigation is warranted to determine whether treatment of any sleep issues resolves symptoms of idiopathic dizziness.

Development and validation of patient-reported outcome measures for sleep disturbance and sleep-related impairments

STUDY OBJECTIVES

To develop an archive of self-report questions assessing sleep disturbance and sleep-related impairments (SRI), to develop item banks from this archive, and to validate and calibrate the item banks using classic validation techniques and item response theory analyses in a sample of clinical and community participants.

DESIGN

Cross-sectional self-report study.

SETTING

Academic medical center and participant homes.

PARTICIPANTS

One thousand nine hundred ninety-three adults recruited from an Internet polling sample and 259 adults recruited from medical, psychiatric, and sleep clinics.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

This study was part of PROMIS (Patient-Reported Outcomes Information System), a National Institutes of Health Roadmap initiative. Self-report item banks were developed through an iterative process of literature searches, collecting and sorting items, expert content review, qualitative patient research, and pilot testing. Internal consistency, convergent validity, and exploratory and confirmatory factor analysis were examined in the resulting item banks. Factor analyses identified 2 preliminary item banks, sleep disturbance and SRI. Item response theory analyses and expert content review narrowed the item banks to 27 and 16 items, respectively. Validity of the item banks was supported by moderate to high correlations with existing scales and by significant differences in sleep disturbance and SRI scores between participants with and without sleep disorders.

CONCLUSIONS

The PROMIS sleep disturbance and SRI item banks have excellent measurement properties and may prove to be useful for assessing general aspects of sleep and SRI with various groups of patients and interventions.

Sleep well, think well: sleep-wake disturbance in mild cognitive impairment

While literature suggests that sleep is important for cognition and mood, and that sleep disturbance is a prominent feature of neurodegenerative and neuropsychiatric disorders, these relationships have not yet been examined in older people ''at risk" of dementia. In this study, 15 older people with the nonamnestic subtype of mild cognitive impairment ([MCI] mean age = 66.7 years, SD = 8.7) underwent psychiatric and neuropsychological assessment. Participants completed sleep diaries, questionnaires, and 2 weeks of actigraphy. Key outcome data during the rest interval were time spent ''awake" or wake after sleep onset (WASO) and the number of arousals/wake bouts. Results showed that even after controlling for age, greater WASO was associated with reduced attention and executive functioning and increased arousals were related to poorer nonverbal learning and problem solving. This preliminary data suggests that sleep-wake disturbance in nonamnestic forms of MCI is related to cognitive functioning and may be indicative of shared neurobiological underpinnings.

Sleep in congestive heart failure

Breathing disorders during sleep are common in congestive heart failure (CHF). Sleep-disordered breathing (SDB) in CHF can be broadly classified as 2 types: central sleep apnea with Cheyne-Stokes breathing, and obstructive sleep apnea. Prevalence of SDB ranges from 47% to 76% in systolic CHF. Treatment of SDB in CHF may include optimization of CHF treatment, positive airway pressure therapy, and other measures such as theophylline, acetazolamide, and cardiac resynchronization therapy. Periodic limb movements are also common in CHF.

Diagnostic characteristics of clinical prediction models for obstructive sleep apnea in different clinic populations

PURPOSE

As predictive factors and their diagnostic values are affected by the characteristics of the population studied, clinical prediction model for obstructive sleep apnea (OSA) may exhibit different diagnostic characteristics in different populations. We aimed to compare the diagnostic characteristics of clinical prediction models developed in two different populations.

METHODS

One hundred seventeen consecutive clinic patients (group 1) were evaluated to develop a clinical prediction model for OSA (local model). The diagnostic characteristics of this local model were compared with those of a foreign model by applying both models to another group of 52 patients who were referred to the same clinic (group 2). All patients underwent overnight polysomnography.

RESULTS

The local model had an area under receiver operator characteristics curve of 79%. A cutoff of 0.6 was associated with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 77.9%, 72.5%, 84.5%, and 63.0%, respectively. The overall diagnostic accuracy, sensitivity, specificity, PPV, and NPV of the local model using data from patients in group 2 were 69.0%, 78.1%, 45.0%, 69.4%, and 56.3%, respectively. The foreign model had an overall diagnostic accuracy of 64.0% when applied to data from patients in group 2. At the optimal cutoff of 17, the foreign model was associated with sensitivity of 38.2%, specificity of 83.3%, NPV of 41.7% and PPV of 81.3%.

CONCLUSIONS

Clinical prediction model for OSA derived from a foreign population exhibits markedly different diagnostic characteristics from one that is developed locally, even though the overall accuracy is similar. Our findings challenge the predictive usefulness and the external validity of clinical prediction models.

Simplifying STOP-BANG: use of a simple questionnaire to screen for OSA in an Asian population

OBJECTIVE

We aim to assess the utility of a simple-to-use 8-point questionnaire in screening for moderate-severe obstructive sleep apnea (OSA) and to assess the validity of cutoffs used to score body mass index (BMI) in this questionnaire.

METHODS

Patients undergoing diagnostic polysomnography (PSG) were asked to fill in a questionnaire with a simple dichotomized 8-point questionnaire, represented by the mnemonic STOP-BANG. A score of 3 or more out of a possible 8 was taken to indicate high risk for presence of OSA. These were then evaluated versus results from the overnight, monitored PSG.

RESULTS

Three hundred and forty-eight patients underwent overnight diagnostic PSG, of whom 319 (91.2%) completed the questionnaire. Seventy-four (22.7%) were classified as being at low risk of OSA and 252 (77.3%) were classified as being high risk. The sensitivities of the STOP-BANG screening tool for an AHI of >5, >15, and >30 were 86.1%, 92.8%, and 95.6%, respectively, with negative predictive values of 84.5% and 93.4% for moderate and severe OSA, respectively. Using cutoffs of 30 or 35 for scoring the BMI did not significantly change the performance of the screening tool.

CONCLUSION

STOP-BANG is a clinically useful tool with high sensitivity that can be used to screen patients for moderate and severe OSA. Using cutoffs of 30 for BMI, 40 cm for neck circumference, and 50 years for age simplifies the application of the tool without affecting performance.

Snoring and obstructive sleep apnea among former World Trade Center rescue workers and volunteers

BACKGROUND

Snoring is a common symptom among workers with adverse health effects from their World Trade Center (WTC) occupational exposures. Rhinitis and upper airway disease are highly prevalent among these workers. Rhinitis has been associated with snoring and, in some studies, with obstructive sleep apnea (OSA). We examined the association of WTC exposure and findings on nocturnal polysomnogram, as well as known predictors of OSA in this patient population.

METHODS

One hundred participants with snoring underwent a polysomnogram to exclude OSA. Comorbidities had been previously evaluated and treated. The apnea-hypopnea index (AHI) defined and categorized the severity of OSA. Age, sex, body mass index (BMI), and WTC exposure variables were examined in bivariate and multiple regression analyses.

RESULTS

Our study sample had a similar prevalence of five major disease categories, as we previously reported. OSA was diagnosed in 62% of the patients and was not associated with any of those disease categories. A trend toward increasing AHI with increasing WTC exposure duration failed to reach the statistical significance (P = 0.14) in multiple regression analysis. An elevated AHI was associated with BMI (P = 0.003) and male sex (P < 0.001).

CONCLUSIONS

OSA was associated with BMI and male sex but not with occupational WTC exposure indicators in this patient population.

The heavy vehicle study: a case-control study investigating risk factors for crash in long distance heavy vehicle drivers in Australia

BACKGROUND

Heavy vehicle transportation continues to grow internationally; yet crash rates are high, and the risk of injury and death extends to all road users. The work environment for the heavy vehicle driver poses many challenges; conditions such as scheduling and payment are proposed risk factors for crash, yet the precise measure of these needs quantifying. Other risk factors such as sleep disorders including obstructive sleep apnoea have been shown to increase crash risk in motor vehicle drivers however the risk of heavy vehicle crash from this and related health conditions needs detailed investigation.

METHODS AND DESIGN

The proposed case control study will recruit 1034 long distance heavy vehicle drivers: 517 who have crashed and 517 who have not. All participants will be interviewed at length, regarding their driving and crash history, typical workloads, scheduling and payment, trip history over several days, sleep patterns, health, and substance use. All participants will have administered a nasal flow monitor for the detection of obstructive sleep apnoea.

DISCUSSION

Significant attention has been paid to the enforcement of legislation aiming to deter problems such as excess loading, speeding and substance use; however, there is inconclusive evidence as to the direction and strength of associations of many other postulated risk factors for heavy vehicle crashes. The influence of factors such as remuneration and scheduling on crash risk is unclear; so too the association between sleep apnoea and the risk of heavy vehicle driver crash. Contributory factors such as sleep quality and quantity, body mass and health status will be investigated. Quantifying the measure of effect of these factors on the heavy vehicle driver will inform policy development that aims toward safer driving practices and reduction in heavy vehicle crash; protecting the lives of many on the road network.

A systematic review of screening questionnaires for obstructive sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) may lead to life-threatening problems if it is left undiagnosed. Polysomnography is the "gold standard" for OSA diagnosis; however, it is expensive and not widely available. The objective of this systematic review is to identify and evaluate the available questionnaires for screening OSA.

SOURCE

We carried out a literature search through MEDLINE, EMBASE, and CINAHL to identify eligible studies. The methodological validity of each study was assessed using the Cochrane Methods Group's guideline.

PRINCIPAL FINDINGS

Ten studies (n = 1,484 patients) met the inclusion criteria. The Berlin questionnaire was the most common questionnaire (four studies) followed by the Wisconsin sleep questionnaire (two studies). Four studies were conducted exclusively on "sleep-disorder patients", and six studies were conducted on "patients without history of sleep disorders". For the first group, pooled sensitivity was 72.0% (95% confidence interval [CI]: 66.0-78.0%; I(2) = 23.0%) and pooled specificity was 61.0% (95% CI: 55.0-67.0%; I(2) = 43.8%). For the second group, pooled sensitivity was 77.0% (95% CI: 73.0-80.0%; I(2) = 78.1%) and pooled specificity was 53.0% (95% CI: 50-57%; I(2) = 88.8%). The risk of verification bias could not be eliminated in eight studies due to insufficient reporting. Studies on snoring, tiredness, observed apnea, and high blood pressure (STOP) and STOP including body mass index, age, neck circumference, gender (Bang) questionnaires had the highest methodological quality.

CONCLUSION

The existing evidence regarding the accuracy of OSA questionnaires is associated with promising but inconsistent results. This inconsistency could be due to studies with heterogeneous design (population, questionnaire type, validity). STOP and STOP-Bang questionnaires for screening of OSA in the surgical population are suggested due to their higher methodological quality and easy-to-use features.

Cognitive and electroencephalographic disturbances in children with attention-deficit/hyperactivity disorder and sleep problems: new insights

There is overlap between the behavioural symptoms and disturbances associated with Attention-Deficit/Hyperactivity Disorder (AD/HD) and sleep problems. The aim of this study was to examine the extent of overlap in cognitive and electrophysiological disturbances identified in children experiencing sleep problems and children with AD/HD or both. Four groups (aged 7-18) were compared: children with combined AD/HD and sleep problems (n=32), children with AD/HD (n=52) or sleep problems (n=36) only, and children with neither disorder (n=119). Electrophysiological and cognitive function measures included: absolute EEG power during eyes open and eyes closed, event-related potential (ERP) components indexing attention and working memory processes (P3), and a number of standard neuropsychological tests. Children with symptoms of both AD/HD and sleep problems had a different profile from those of children with either AD/HD or sleep problems only. These findings suggest it is unlikely that disturbances in brain and cognitive functioning associated with sleep problems also give rise to AD/HD symptomatology and consequent diagnosis. Furthermore, findings suggest that children with symptoms of both AD/HD and sleep problems may have a different underlying aetiology than children with AD/HD-only or sleep problems-only, perhaps requiring unique treatment interventions.

Obstructive sleep apnea in patients undergoing bariatric surgery--a tertiary center experience

BACKGROUND

The patient population that is evaluated for bariatric surgery is characterized by a very high body mass index (BMI). Since obesity is the most important risk factor for obstructive sleep apnea (OSA), sleep disordered breathing is highly prevalent in this population. If undiagnosed before bariatric surgery, untreated OSA can lead to perioperative and postoperative complications. Debate exists whether all patients that are considered for bariatric surgery should undergo polysomnography (PSG) evaluation and screening for OSA as opposed to only those patients with clinical history or examination concerning sleep disordered breathing. We examined the prevalence and severity of OSA in all patients that were considered for bariatric surgery. We hypothesized that, by utilizing preoperative questionnaires (regarding sleepiness and OSA respiratory symptoms) in combination with menopausal status and BMI data, we would be able to predict which subjects did not have sleep apnea without the use of polysomnography. In addition, we hypothesized that we would be able to predict which subjects had severe OSA (apnea-hypopnea index (AHI) > 30).

METHODS

Three hundred forty-two consecutive subjects, evaluated for bariatric surgery from November 1, 2005 to January 31, 2007 underwent overnight polysomnography and completed questionnaires regarding sleepiness, menopausal status, and respiratory symptoms related to OSA. Apneas and hypopneas were classified as follows: mild apnea 5 ≤ AHI ≤ 15, moderate apnea 15 < AHI ≤ 30, and severe apnea AHI > 30.

RESULTS

The overall sample prevalence of OSA was 77.2%. Of these, 30.7% had mild OSA; 19.3% had moderate OSA, and 27.2% had severe OSA. Among men, the prevalence of OSA was 93.6% and 73.5% among women. The mean AHI (events per hour) for men with OSA was 49.2 ± 35.5 and 26.3 ± 28.3 for women with OSA. Separate logistic regression models were developed for the following three outcomes: AHI ≥ 5 events per hour, AHI > 15 events per hour, and AHI > 30 events per hour. When predicting these three levels of OSA severity, the area under the curve (AUC) values were: 0.8, 0.72, and 0.8, respectively. The negative predictive value for the presence of sleep apnea (AHI ≥ 5) was 75% when using the most stringent possible cutoff for the prediction model.

CONCLUSIONS

The prevalence of OSA in all patients considered for bariatric surgery was greater than 77%, irrespective of OSA symptoms, gender, menopausal status, age, or BMI. The prediction model that we developed for the presence of OSA (AHI ≥ 5 events per hour) has excellent discriminative ability (evidenced by an AUC value of 0.8). However, the negative prediction values for the presence of OSA were too low to be clinically useful due to the high prevalence of OSA in this high-risk group. We demonstrated that, by utilizing even the most stringent possible cutoff values for the prediction model, OSA cannot be predicted with enough certainty. Therefore, we advocate routine PSG testing for all patients that are considered for bariatric surgery.

The Berlin questionnaire for sleep apnea in a sleep clinic population: relationship to polysomnographic measurement of respiratory disturbance

The Berlin questionnaire (BQ) has been used to help identify patients at high risk of having sleep apnea in primary care and atrial fibrillation patients. The BQ may be a useful adjunct in sleep medicine and research, but it has never been validated in a sleep clinic population. The aim of the study is to determine the specificity and sensitivity of the BQ compared to the respiratory disturbance index (RDI) values obtained from two nights of polysomnographic recording in a sleep clinic population. This is a retrospective chart review study of 130 sleep clinic patients. Patients' demographics, BQ scores, RDI measurements, and sleep study parameters were extracted from the patients' chart. Of the 130 charts reviewed, the BQ identified 76 (58.5%) as being at high-risk of having sleep apnea, but overnight polysomnography found only 34 of the 130 patients (26.2%) had an RDI > 10. The BQ performed with 0.62 sensitivity and 0.43 specificity at the RDI > 10 level. Due to the low sensitivity and specificity as well as the large number of false negatives and positives, the Berlin questionnaire is not an appropriate instrument for identifying patients with sleep apnea in a sleep clinic population.

Autonomic activation during sleep in posttraumatic stress disorder and panic: a mattress actigraphic study

BACKGROUND

While it has been reported that persons with posttraumatic stress disorder (PTSD) manifest tonic autonomic activation, the literature contains numerous counterexamples. In revisiting the question, this study employed a novel method of mattress actigraphy to unobtrusively estimate heart rate and respiratory sinus arrhythmia over multiple nights of sleep in the home.

METHODS

Sleep cardiac autonomic status was estimated in four diagnostic groups, posttraumatic stress disorder, panic disorder, persons comorbid for both conditions, and control subjects. All 59 participants were community-residing nonveterans screened for sleep apnea and periodic leg movement disorder with polysomnography. Heart rate and respiratory sinus arrhythmia were calculated from the kinetocardiogram signal measured via accelerometers embedded in a mattress topper. Times in bed and asleep were also estimated. Per participant data were obtained from a median of 12 nights.

RESULTS

Both posttraumatic stress disorder and posttraumatic stress disorder/panic disorder comorbid groups exhibited significantly higher heart rates and lower respiratory sinus arrhythmia magnitudes than panic disorder participants and control subjects. Panic disorder participants were indistinguishable from control subjects. The PTSD-only group exhibited longer times in bed and longer times presumably asleep than the other three groups.

CONCLUSIONS

In this study, posttraumatic stress disorder, but not panic disorder, was associated with altered cardiac autonomic status during sleep. Among participants meeting criteria for PTSD alone, autonomic activation co-occurred with prolongation of actigraphic sleep.

The feasibility of using auto-titrating continuous positive airway pressure to treat obstructive sleep apnoea after acute tetraplegia

STUDY DESIGN

A prospective cohort with acute tetraplegia.

OBJECTIVES

Obstructive sleep apnoea (OSA) is common within weeks of tetraplegia. This study aimed at determining the feasibility of auto-titrating continuous positive airway pressure (CPAP) to treat OSA after acute tetraplegia.

SETTING

The Victorian Spinal Cord Service, Melbourne, Australia.

METHODS

Participants underwent full, portable polysomnography. Those with an apnoea hypopnoea index of more than 10 events per hour were defined as having OSA and were offered treatment with CPAP. Treatment adherence was objectively monitored, and measures of quality of life, sleepiness and functional outcomes were determined at enrollment and 3 months later at study conclusion.

RESULTS

A total of 44 patients were admitted to our Spinal Cord Service over 9 months, and 19 participated. Fourteen of them had OSA and seven were adherent with therapy for 3 months. Compared with those who did not have OSA, and with those with OSA who were not adherent with CPAP, those who adhered to CPAP were older (mean (s.d.) age 54 years (13) versus non-adherent 28 years (15) and no OSA 29 years (10)) and heavier (body mass index (BMI) 32.5 (11.7), 24.1 (3.7) and 20.6 (3.1), respectively). CPAP-adherant patients and those without OSA showed a 50% or greater improvement in their state sleepiness over the 3 months. Patients with OSA who did not tolerate CPAP had no improvement in sleepiness.

CONCLUSION

Auto-titrating CPAP is a feasible treatment for OSA in acute tetraplegia. Intensive clinical support was required initially, and a tolerance of therapy for at least 4 h for one of the first 3 days was predictive of good CPAP usage.

SPONSORSHIP

Transport Accident Commission.

Obstructive sleep apnea among obese patients with type 2 diabetes

OBJECTIVE

To assess the risk factors for the presence and severity of obstructive sleep apnea (OSA) among obese patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Unattended polysomnography was performed in 306 participants.

RESULTS

Over 86% of participants had OSA with an apnea-hypopnea index (AHI) >or=5 events/h. The mean AHI was 20.5 +/- 16.8 events/h. A total of 30.5% of the participants had moderate OSA (15 <or= AHI <30), and 22.6% had severe OSA (AHI >or=30). Waist circumference (odds ratio 1.1; 95% CI 1.0-1.1; P = 0.03) was significantly related to the presence of OSA. Severe OSA was most likely in individuals with a higher BMI (odds ratio 1.1; 95% CI 1.0-1.2; P = 0.03).

CONCLUSIONS

Physicians should be particularly cognizant of the likelihood of OSA in obese patients with type 2 diabetes, especially among individuals with higher waist circumference and BMI.

The development of a sleep disorder screening program in Australian community pharmacies

OBJECTIVE

To develop, pilot and determine the feasibility of a sleep-specific screening and awareness program in community pharmacies.

SETTING

The screening was piloted in five Australian community pharmacies.

METHOD

The Pharmacy Tool for Assessment of Sleep Health was constructed by drawing on known relationships between sleep disorders, and lifestyle factors, medical conditions and medications. Four validated instruments were used in the screening tool: the Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), Multivariable Apnea Prediction Index (MAPI) and International Restless Legs Syndrome Study Group Screening Criteria (IRLS). These instruments were used to predict the participant's risk of a sleep disorder and the results were compared with reported lifestyle, medical and medication factors. On-site training of consenting pharmacists was provided, followed by an eight week client recruiting and screening period. Feedback was elicited from participating pharmacists and clients.

MAIN OUTCOME MEASURE

The feasibility of, and trends found from, the developed screening tool and protocol.

RESULTS

Of 167 clients who requested or were invited to participate by pharmacists, 84 (50.3%) were screened. Analysis of collected data indicated that 33.3%, 21.4% and 27.4% of participants were at risk of having or developing insomnia, obstructive sleep apnea (OSA) and restless legs syndrome (RLS) respectively, while 38.1% were not at risk of any of the screened disorders. OSA odds increased 12.8 times (95% CI: 3.2-50.4) with diabetes and 4.9 times (1.2-20.9) with opioid use, while shift workers were 8.4 times (1.6-43.2) more likely to have insomnia. Participants and pharmacists reported the screening protocol and instrument was user friendly and feasible.

CONCLUSION

The development and pilot of this screening tool was successful. The prevalence of sleep disorders in the sampled population was high but generally consistent with previous studies on the general population. Furthermore, associations found may form a foundation for a clinical algorithm to identify those at a higher risk of having or developing a sleep disorder. Further work is required to validate this screening tool in the community pharmacy context.

The effects of a poor night sleep on mood, cognitive, autonomic and electrophysiological measures

Sustained sleep problems such as insomnia have been shown to be detrimental to health. This study examines the less understood, finer grained effects of a single bad night's sleep on mood, cognitive, autonomic and electrophysiological functions. We assessed 338 individuals who had no symptoms of a clinical sleep disorder. Of these, 226 individuals had six or more hours sleep and 112 individuals had less than six hours sleep prior to an assessment of mood, cognition, autonomic and electrophysiological functioning. Individuals in the relatively "bad night" sleep group had higher depression, anxiety, and stress scores and reported significantly poorer overall wellbeing. They made more errors on simple cognitive tasks while more complex task components were unaffected. They also had an increase in heart rate and EEG alpha and beta power at rest. Participants in this study had no symptoms of a clinical sleep disorder, however the effects of a poor night sleep on measures of mood, cognition, autonomic and electrophysiological function were similar, but less severe than those reported in insomnia patients. The integrative profile of measures reported here point to an increase in physiological arousal and sub-optimal cognition, following a poor night's sleep.

Sleepiness, physical activity, and functional outcomes in veterans with type 2 diabetes

The purpose of this study was to explore the association between daytime sleepiness on physical activity and functional outcomes in veterans with type 2 diabetes. Physical activity was based on mean self-reported minutes walked per week; the American Diabetes Association's recommendation of 150 minutes activity per week was used to dichotomize participants as sedentary or active. The Epworth Sleepiness Scale measured sleepiness. Sleepy participants had significantly lower scores on the Functional Outcomes of Sleep Questionnaire. Sleepiness was predictive of being sedentary (p = .01) after controlling for age and body mass index. The conclusion is that daytime sleepiness may impede physical activity among veterans with diabetes, confounding self-management.

Evaluation of the reliability and validity of the Medical Outcomes Study sleep scale in patients with painful diabetic peripheral neuropathy during an international clinical trial

Background

Sleep is an important element of functioning and well-being. The Medical Outcomes Study Sleep Scale (MOS-Sleep) includes 12 items assessing sleep disturbance, sleep adequacy, somnolence, quantity of sleep, snoring, and awakening short of breath or with a headache. A sleep problems index, grouping items from each of the former domains, is also available. This study evaluates the psychometric properties of MOS-Sleep Scale in a painful diabetic peripheral neuropathic population based on a clinical trial conducted in six countries.

Methods

Clinical data and health-related quality of life data were collected at baseline and after 12 weeks of follow-up. Overall, 396 patients were included in the analysis. Psychometric properties of the MOS-Sleep were assessed in the overall population and per country when the sample size was sufficient. Internal consistency reliability was assessed by Cronbach's alpha; the structure of the instrument was assessed by verifying item convergent and discriminant criteria; construct validity was evaluated by examining the relationships between MOS-Sleep scores and sleep interference and pain scores, and SF-36 scores; effect-sizes were used to assess the MOS-Sleep responsiveness. The study was conducted in compliance with United States Food and Drug Administration regulations for informed consent and protection of patient rights.

Results

Cronbach's alpha ranged from 0.71 to 0.81 for the multi-item dimensions and the sleep problems index. Item convergent and discriminant criteria were satisfied with item-scale correlations for hypothesized dimensions higher than 0.40 and tending to exceed the correlations of items with other dimensions, respectively. Taken individually, German, Polish and English language versions had good internal consistency reliability and dimension structure. Construct validity was supported with lower sleep adequacy score and greater sleep problems index scores associated with measures of sleep interference and pain scores. In addition, correlations between the SF-36 scores and the MOS-Sleep scores were low to moderate, ranging from -0.28 to -0.53. Responsiveness was supported by effect sizes > 0.80 for patients who improved according to the mean sleep interference and pain scores and clinician and patient global impression of change (p < 0.0001).

Conclusion

The MOS-Sleep had good psychometric properties in this painful diabetic peripheral neuropathic population.

Trial registration

As this study was conducted from 2000 to 2002 (i.e., before the filing requirement came out), no trial registration number is available.

Exploring the effects of lifestyle, sleep factors and driving behaviors on sleep-related road risk: a study of Greek drivers

PURPOSE

The present study explored the effect of various lifestyle patterns and sleep-related factors on the sleep-related road risk. Sleep-related factors included daytime sleepiness, drowsy driving and quality/quantify of sleep.

METHODS

A sample of 1366 non-professional drivers aged 19-65 was selected from the broader Athens area of Greece, using stratified random sampling. The questionnaire solicited information on the participants' socio-demographic characteristics, driving background, lifestyle patterns, sleep quality and quantity, daytime sleepiness, drowsy driving behavior and sleep-related road risk.

RESULTS

Sleep-related road risk was affected by gender, quantity of night sleep and drowsy driving behavior. Drowsy driving behavior was shown to be related to gender, daytime sleepiness, sleep quality and the lifestyle of "amusement". Daytime sleepiness was correlated with sleep quality and the lifestyles of "amusement" and "sport". Finally, sleep quality and quantity were significantly affected by the lifestyles of "amusement" and "yuppies-workaholic".

CONCLUSION

The current study has identified a number of risk factors in sleep-related crash risk in the general population of drivers. By raising public awareness the health and safety community can play an important role in reducing, if not preventing, the consequences of this public health problem.

Risks and advantages of detecting individuals unfit to drive: a Markov decision analysis

BACKGROUND

Many countries have initiated legislation to detect individuals who are unfit to drive, without any evidence that positive effects of these screening procedures outweigh negative effects.

OBJECTIVE

To measure the potential effectiveness of a screening program to detect individuals unfit to drive.

DESIGN

Markov decision analysis was used to compare no screening to two potential screening strategies.

PARTICIPANTS

Hypothetical cohorts of 10,000 45-year-old, 65-year-old, 75-year-old and 85-year-old individuals seen in primary care practices.

INTERVENTIONS

Within the screening strategies: a clinical test without on-road confirmatory testing; a clinical test with on-road confirmatory testing, and an imposed driving cessation for patients with a positive test.

MEASUREMENTS

For each strategy, we compared for two conditions (sleep disorders and dementia) the numbers of crash-related consequences prevented and of adverse events induced (primary objective) and measured the gain in quality-adjusted life years (secondary objective).

RESULTS

For sleep disorders, on-road confirmatory annual testing was the preferred strategy. Whatever the medical condition and age when screening starts, no screening was always better than single-test screening without an on-road confirmatory testing. In sensitivity analyses, these baseline conclusions were only affected by extreme values of test specificity.

CONCLUSION

Because of the expected difficult application and cost of road tests and annual screening by clinicians, the most acceptable strategy from public health, clinical, and individual points of view is likely to be no screening.

Daytime sleepiness, diabetes, and psychological well-being

Nominal group technique was used with persons with type 2 diabetes to identify and rank the severity of problems associated with being sleepy. Participants were adults who were subjectively sleepy according to the Epworth Sleepiness Scale. Daytime sleepiness was associated with a general decrease in motivation to engage in activities that are important to the management of diabetes. Because decreased motivation may have a negative influence on psychological well-being, it is important that health care providers assess not only for how well their patients' diabetes is being controlled, but also for sleep disturbances and the patients' general state of psychological well-being.

Investigating the associations between nocturia and sleep disorders in perimenopausal women

PURPOSE

We determined the associations between nocturia and sleep disorders in perimenopausal women.

MATERIALS AND METHODS

A total of 100 women with nocturia were compared to 200 without nocturia. Obstructive sleep apnea, insomnia, anxiety and menopausal stage were assessed using validated questionnaires. Comorbidities associated with nocturia were determined by bivariate analysis and multivariate logistic regression.

RESULTS

Independent associations for nocturia were anxiety (OR 2.11, 95% CI 1.08-4.13), black American race (OR 2.00, 95% CI 1.06-3.85), obstructive sleep apnea symptoms (OR 1.73, 95% CI 1.18-2.53) and insomnia (OR 1.11, 95% CI 1.05-1.12).

CONCLUSIONS

Nocturia is associated with sleep disorders in perimenopausal women.

Sleep disordered breathing in chronic heart failure

Heart failure is a growing problem, placing an increasing burden on public health resources and continuing to exert a high toll in mortality and morbidity. Sleep disordered breathing (SDB) is also a major public health problem and is associated with an increased risk of fatal and non-fatal cardiovascular events. Current evidence suggests SDB, particularly central SDB, is more prevalent in patients with chronic heart failure (CHF) than in the general population, but is under-diagnosed as SDB symptoms are less prevalent in CHF. This is further hampered by the absence of a simple and accurate screening tool and limited access to sleep facilities to diagnose SDB in the large numbers of patients with CHF. The presence of SDB in patients with CHF imposes increased haemodynamic burdens and results in autonomic abnormalities. Central SDB is an independent marker of worse prognosis, and evidence is increasing that obstructive SDB is also associated with higher mortality in patients with CHF. Optimal treatment of central SDB in these patients remains uncertain. While evidence of efficacy of positive pressure ventilation is stronger in obstructive SDB, improvement in survival for patients with both CHF and SDB awaits definitive trials. This paper summarizes our current understanding of the pathophysiology of SDB in CHF, and the cardiovascular consequences, and reviews the evidence for the beneficial effects of treatment of SDB in patients with CHF.