Brain Function and Sleep Apnea, a clinical cross-sectional study

Proposal details

Title: Brain Function and Sleep Apnea, a clinical cross-sectional study
Research Area(s): Sleep
Background: Obstructive sleep apnea is associated with conditions that account for the leading causes of mortality in adults: hypertension, cardiovascular, and cerebrovascular diseases. In addition, several neurobehavioral morbidities that are of potentially great public health and economic importance are linked with OSA, including daytime sleepiness and impaired cognitive function .This paper follows from an earlier study examining differences in brain function between questionnaire-defined obstructive sleep apnea (OSA) and matched controls (Wong KKH, et al. J Integr Neurosci 2006; 5: 111-121). A limitation of that study was that the group classified as having OSA was identified using a questionnaire -the diagnosis or severity of OSA could not be established objectively. In this study, patients from a sleep centre with laboratory-confirmed obstructive sleep apnea (OSA) will be compared with matched controls drawn from the Brain Resource International Database. It may help us determine components of the testing that can be used in a clinical setting to identify patients with OSA who show brain functional impairment, so that treatment can be targeted and monitored
Aims: 1. Patients with OSA show deficits in attention, vigilance and executive functioning. 2. We seek to confirm the between-group deficits previously identified in the BRID normative database study, with the expectation that differences in performance may be greater in this clinical OSA population.
Method: Subjects: OSA group: subjects aged 18-70 attending a tertiary-referral sleep centre with diagnosed, untreated obstructive sleep apneoa of at least moderate severity (polysomnography apnea-hypopnea index 15 or greater per hour). Control group: subjects from the Brain Resource International Normative Database scoring 0.50 or below on the Multivariable Apnea Prediction Index, who are matched for age, gender and years of education to individual subjects in the OSA group, in a 4:1 control to patient ratio where available. The procedure for selection of controls has been tested, and a 4:1 matching has been found to be feasible for this study population. Exclusion criteria: a history of attention deficit hyperactivity disorder, schizophrenia, bipolar disorder or other major psychiatric illness.ANALYSIS: Demographic details: comparisons will be made between groups (OSA and Controls) for age, gender, years of education, alcohol consumption, smoking and drug taking behaviour. For the EEG measures (and, separately, the ERP measures) MANCOVA with group (osa, control), brain region (anterior, posterior), and age (continuous variable) as predictors. ANCOVA will be used for components of the cognitive performance profile battery and DASS ,BRIEFand NEO-FFI subscales (social cognition), with: group, age and years of education as predictors.