Relation of measures of sleep-disordered breathing to neuropsychological functioning.
ABSTRACT Sleep-disordered breathing (SDB) has been associated with neuropsychological (NP) deficits. The extent to which such effects are attributable to unmeasured confounders or selection biases, or are manifest across a range of SDB is unclear. The relationship of SDB with a broad range of NP functions was examined in 100 volunteers with a spectrum of SDB and without underlying comorbidity. Factor analysis suggested that the NP tests could be summarized as four constructs: declarative memory, signal discrimination, working memory, and set shifting. These factors plus vigilance were dependent variables. Independent variables were age, the respiratory disturbance index (RDI), a sleepiness score, the arousal index, and sleep-associated hypoxemia. Factors "declarative memory" (measuring 25% of the common variance, alpha = 0.95), "signal discrimination" (10% variance, alpha = 0.70), and "working memory" (9% variance, alpha = 0.52) were each significantly, linearly predicted by hypoxemia and/or the RDI, with no evidence for significant threshold effects. SDB measures accounted for 4-6% of the variance in NP constructs. In contrast, sleepiness best predicted vigilance. Thus, adverse exposures (hypoxemia or RDI) during sleep may negatively influence NP functions in a dose-response relationship, and, other than vigilance, these effects may not be directly attributable to sleepiness.
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ABSTRACT: Study Objectives: As obstructive sleep apnea (OSA) is associated with a higher risk of motor vehicle crashes, there is increasing regulatory interest in the identification of commercial motor vehicle (CMV) drivers with this condition. This study aimed to determine the relationship between subjective versus objective assessment of OSA in CMV drivers. Design: Cross-sectional survey. Settings: Heavy vehicle truck stops located across the road network of 2 large Australian states. Participants: A random sample of long distance commercial vehicle drivers (n = 517). Interventions: None. Measurements and Results: Drivers were interviewed regarding their driving experience, personal health, shift schedules, payments, and vari- ous questions on sleep and tiredness in order to describe their sleep health across a range of variables. In addition, home recordings using a flow monitor were used during one night of sleep. Only 4.4% of drivers reported a previous diagnosis of sleep apnea, while our at home diagnostic test found a further 41% of long-distance heavy vehicle drivers likely to have sleep apnea. The multivariable apnea prediction index, based on self- report measures, showed poor agreement with the home-monitor detected sleep apnea (AUC 0.58, 95%CI = 0.49-0.62), and only 12% of drivers reported daytime sleepiness (Epworth Sleepiness Scale score > 10). Thirty-six percent of drivers were overweight and a further 50% obese; 49% of drivers were cigarette smokers. Conclusions: Sleep apnea remains a significant and unrecognized problem in CMV drivers, who we found to have multiple health risks. Objective testing for this sleep disorder needs to be considered, as symptom reports and self-identification appear insufficient to accurately identify those at risk. Keywords: Obstructive sleep apnea, measurement, sleepiness, commercial vehicle drivers, policy Citation: Sharwood LN; Elkington J; Stevenson M; Grunstein RR; Meuleners L; Ivers RQ; Haworth N; Norton R; Wong KK. Assessing sleep- iness and sleep disorders in Australian long-distance commercial vehicle drivers: self-report versus an “at home” monitoring device.Sleep 04/2012; 35(4):469-475. · 5.10 Impact Factor
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ABSTRACT: STUDY OBJECTIVES: To examine episodic memory performance in individuals with obstructive sleep apnea (OSA). DESIGN: Meta-analysis was used to synthesize results from individual studies examining the impact of OSA on episodic memory performance. The performance of individuals with OSA was compared to healthy controls or normative data. PARTICIPANTS: Forty-two studies were included, comprising 2,294 adults with untreated OSA and 1,364 healthy controls. Studies that recorded information about participants at baseline prior to treatment interventions were included in the analysis. MEASUREMENTS: PARTICIPANTS WERE ASSESSED WITH TASKS THAT INCLUDED A MEASURE OF EPISODIC MEMORY: immediate recall, delayed recall, learning, and/or recognition memory. RESULTS: The results of the meta-analyses provide evidence that individuals with OSA are significantly impaired when compared to healthy controls on verbal episodic memory (immediate recall, delayed recall, learning, and recognition) and visuo-spatial episodic memory (immediate and delayed recall), but not visual immediate recall or visuo-spatial learning. When patients were compared to norms, negative effects of OSA were found only in verbal immediate and delayed recall. CONCLUSIONS: This meta-analysis contributes to understanding of the nature of episodic memory deficits in individuals with OSA. Impairments to episodic memory are likely to affect the daily functioning of individuals with OSA. CITATION: Wallace A; Bucks RS. Memory and obstructive sleep apnea: a meta-analysis. SLEEP 2013;36(2):203-220.Sleep 01/2013; 36(2):203-220. · 5.10 Impact Factor
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ABSTRACT: Obstructive sleep apnea is a common disorder, characterized by repeated episodes of upper airway obstruction during sleep, resulting intermittent hypoxia and disruption of the normal sleep pattern, which caused cognitive dysfunction in these patients. Nasal continuous positive airway pressure is the treatment of choice for this disorder. The aim of the study is to evaluate the effect of short-term positive airway pressure on sleep pattern (polisomnographic measures), cognitive function and anxiety. Twenty four newly diagnosed and previously untreated patients with obstructive sleep apnea were evaluated a battery of neuropsychological tests before and after 2 and a half months of the treatment. We focused on working memory, short and long-term episodic memory, executive functions, anxiety and subjective sleepiness. Our results showed that the two and half month of treatment improved the respiration during sleep, sleep pattern and the subjective sleepiness. We found improvement in short- and long-term verbal memory, and complex working memory. Despite of treatment we did not find improvement in visuospatial learning. These results reveal that 2 and a half months of positive airway pressure treatment restored not only the normal respiration during sleep and normal sleep pattern, but also the cognitive functions. Our study suggests that cognitive dysfunction is at least partial reversible in obstructive sleep apnea patients after positive airway pressure treatment.Ideggyógyászati szemle 05/2012; 65(5-6):181-94. · 0.35 Impact Factor