Relation of measures of sleep-disordered breathing to neuropsychological functioning.
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.
Adams
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Department of Psychology and Neurology, Case Western Reserve University, Louis Stokes Cleveland, Ohio, USA.
Strauss
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M
Schluchter
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M
Redline
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S
D001288:Attention; D003657:Decision Making; D004192:Discrimination, Psychological; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D008568:Memory; D008606:Mental Processes; D008875:Middle Aged; D009483:Neuropsychological Tests; D017286:Polysomnography; D011597:Psychomotor Performance; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology / Q000523:psychology*; D012894:Sleep Stages