BackgroundThis study aimed to identify characteristics associated with cognitive impairment in older individuals with obstructive sleep apnoea (OSA) using the Addenbrooke’s Cognitive Examination-Revised (ACE-R) that could aid in stratifying those at higher risk for impairment.MethodsWe analysed existing cross-sectional datasets that measured the performance of 89 adult patients (aged 50–85 years) with OSA on the ACE-R cognitive test. Receiver operating characteristic curves and logistic regression analysis were utilised to identify associations between impairment status and various factors, including demographic characteristics, self-reported sleepiness, cognitive complaints, and OSA severity.ResultsAccording to established thresholds (ACE-R ≤ 88), 36% of participants were cognitively impaired. When adjusted for age and education, the strongest factors associated with impairment status were prior measures of arousal index (cut-off: ≥28events/hr, OR: 5.67, p < 0.01), sleep mean SpO2 (cut-off: ≤92%, OR: 3.52, p < 0.05), 3% oxygen desaturation index (cut-off: ≥27events/hr, OR: 3.75, p < 0.05), and sleep time spent under 90% SpO2 (cut-off: ≥9%, OR: 3.16, p < 0.05). Combining these factors achieved a high sensitivity (≥ 93%) of detecting impairment within this cohort. Conversely, the apnoea-hypopnoea index, daytime sleepiness, and cognitive complaints were not associated with impairment status.ConclusionsThe ACE-R identified a significant proportion of patients with OSA as having cognitive impairment. Traditional indices of sleep fragmentation and hypoxaemia may allow clinicians to identify at-risk patients for cognitive evaluation, however further studies are needed to validate these findings and explore whether poor cognitive performance can be remediated via OSA treatment.
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