Severe desaturations increase psychomotor vigilance task-based median reaction time and number of lapses in obstructive sleep apnoea patients

Abstract

Current diagnostic parameters estimating obstructive sleep apnoea (OSA) severity have a poor connection to the psychomotor vigilance of OSA patients. Thus, we aimed to investigate how the severity of apnoeas, hypopnoeas and intermittent hypoxaemia is associated with impaired vigilance.We retrospectively examined type I polysomnography data and corresponding psychomotor vigilance tasks (PVTs) of 743 consecutive OSA patients (apnoea–hypopnoea index (AHI) ≥5 events·h−1). Conventional diagnostic parameters (e.g. AHI and oxygen desaturation index (ODI)) and novel parameters (e.g. desaturation severity and obstruction severity) incorporating duration of apnoeas and hypopnoeas as well as depth and duration of desaturations were assessed. Patients were grouped into quartiles based on PVT outcome variables. The odds of belonging to the worst-performing quartile were assessed. Analyses were performed for all PVT outcome variables using binomial logistic regression.A relative 10% increase in median depth of desaturations elevated the odds (ORrange 1.20–1.37, p<0.05) of prolonged mean and median reaction times as well as increased lapse count. Similarly, an increase in desaturation severity (ORrange 1.26–1.52, p<0.05) associated with prolonged median reaction time. Female sex (ORrange 2.21–6.02, p<0.01), Epworth Sleepiness Scale score (ORrange 1.05–1.07, p<0.01) and older age (ORrange 1.01–1.05, p<0.05) were significant risk factors in all analyses. In contrast, increases in conventional AHI, ODI and arousal index were not associated with deteriorated PVT performance.These results show that our novel parameters describing the severity of intermittent hypoxaemia are significantly associated with increased risk of impaired PVT performance, whereas conventional OSA severity and sleep fragmentation metrics are not. These results underline the importance of developing the assessment of OSA severity beyond the AHI.

Increased nocturnal arterial pulsation frequencies of obstructive sleep apnoea patients is associated with an increased number of lapses in a psychomotor vigilance task

“…Analysis comprising only female patients showed smaller differences between best and worst performers in the frequency content of PPG. Based on previous studies, women tend to perform worse than males in PVT [10,18,25], which was observed in this cohort also (Table 1). Women also exhibit a higher resting heart rate and different cardiac regulation sensitivity [26].…”

“…In addition, we aim to examine whether larger within-test variation in reaction times is associated with spectral features of PPG. As earlier literature shows that PVT performance is highly sex-dependent [10,18], we perform the analyses separately for men and women. [20].…”

“…Previous studies show that severe intermittent hypoxaemia, quantified by the duration, depth and frequency of oxygen desaturations, is associated with daytime sleepiness and cognitive decline in OSA patients [ 7 – 10 ]. However, desaturation metrics and other parameters quantifying the severity of OSA are not fully capable of explaining the impaired performance in PVT in OSA patients having shallow and short desaturations [ 10 ]. This suggests that additional factors could explain the associations between OSA and poor PVT performance.…”

Detailed Assessment of Sleep Architecture With Deep Learning and Shorter Epoch-to-Epoch Duration Reveals Sleep Fragmentation of Patients With Obstructive Sleep Apnea

“…A similar effect was also seen by Norman et al who reported that no significant differences exist between the normal and mild OSA groups in traditional sleep parameters and differences only emerge when considering the sleep continuity with survival analysis [23]. However, it has to be noted that the division into OSA severity groups is highly artificial and simplistic and the severity assessment with AHI might not sufficiently reflect the physiological effects of OSA [24][25][26]. Therefore, it could be beneficial to study how sleep fragmentation varies when defining the OSA severity differently or even attempt to define the severity of OSA by using sleep fragmentation as a metric.…”

<p>Associations of OSA and Nocturnal Hypoxemia with Strength and Body Composition in Community Dwelling Middle Aged and Older Men</p>

“…Hypoxemia, but not AHI, is linked with self-report and objectively measured excessive daytime sleepiness. 40 , 41 Yet, excessive daytime sleepiness, measured by the Epworth Sleepiness Scale (ESS), was not associated with HGS, muscle mass, nor fat mass, in either the unadjusted and adjusted analyses ( Supplementary S2 ). A single previous study showed an ESS score above 15, coupled with self-report snoring or apneic events, is associated with reduced HGS, after adjusting for various confounders.…”