Verbal memory is linked to average oxygen saturation during sleep, not the apnea-hypopnea index nor novel hypoxic load variables

• Published in: Sleep medicine 2024-11, Vol.123, p.29-36
• Main Authors: Thorisdottir, K., Hrubos-Strøm, H., Karhu, T., Nikkonen, S., Dammen, T., Nordhus, I.H., Leppänen, T., Jónsdóttir, M.K., Arnardottir, E.S.
• Format: Article
• Language: English
• Subjects: Adult; Apnea-hypopnea Index; Executive function; Executive Function - physiology; Female; Humans; Hypoxia - physiopathology; Hypoxic load; Male; Memory - physiology; Middle Aged; Neuropsychological Tests - statistics & numerical data; Obstructive sleep apnea; Oxygen Saturation - physiology; Polysomnography; Rey Auditory Verbal Learning Test; Severity of Illness Index; Sleep - physiology; Sleep Apnea, Obstructive - diagnosis; Sleep Apnea, Obstructive - physiopathology; Stroop Test; Verbal learning; Verbal Learning - physiology
• ISSN: 1389-9457; 1878-5506; 1878-5506
• DOI: 10.1016/j.sleep.2024.08.028

The apnea-hypopnea index (AHI) is the current diagnostic parameter for diagnosing and estimating the severity of obstructive sleep apnea (OSA). It is, however, poorly associated with the main clinical symptom of OSA, excessive daytime sleepiness, and with the often-seen cognitive decline among OSA patients. To better evaluate OSA severity, novel hypoxic load parameters have been introduced that consider the duration and depth of oxygen saturation drops associated with apneas or hypopneas. The aim of this paper was to compare novel hypoxic load parameters and traditional OSA parameters to verbal memory and executive function in OSA patients. A total of 207 adults completed a one-night polysomnography at sleep laboratory and two neuropsychological assessments, the Rey Auditory Verbal Learning Test and Stroop test. Results: Simple linear regression analyses were used to evaluate independent associations between each OSA parameter and cognitive performance. Associations were found between immediate recall and arousal index, hypoxia