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- Abdollahi, Anna M., et al.
(författare)
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Comparison of actigraphy-measured and parent-reported sleep in association with weight status among preschool children
- 2024
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Ingår i: Journal of Sleep Research. - : John Wiley & Sons. - 0962-1105 .- 1365-2869. ; 33:1
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Tidskriftsartikel (refereegranskat)abstract
- This study compared weekday and weekend actigraphy-measured and parent-reported sleep in relation to weight status among preschool-aged children. Participants were 3–6 years old preschoolers from the cross-sectional DAGIS-study with sleep data for ≥2 weekday and ≥2 weekend nights. Parents-reported sleep onset and wake-up times were gathered alongside 24 h hip-worn actigraphy. An unsupervised Hidden-Markov Model algorithm provided actigraphy-measured night time sleep without the guidance of reported sleep times. Waist-to-height ratio and age-and-sex-specific body mass index characterised weight status. Comparison of methods were assessed with consistency in quintile divisions and Spearman correlations. Associations between sleep and weight status were assessed with adjusted regression models. Participants included 638 children (49% girls) with a mean ± SD age of 4.76 ± 0.89. On weekdays, 98%–99% of actigraphy-measured and parent-reported sleep estimates were classified in the same or adjacent quintile and were strongly correlated (rs = 0.79–0.85, p < 0.001). On weekends, 84%–98% of actigraphy-measured and parent-reported sleep estimates were respectively classified and correlations were moderate to strong (rs = 0.62–0.86, p < 0.001). Compared with actigraphy-measured sleep, parent-reported sleep had consistently earlier onset, later wake-up, and greater duration. Earlier actigraphy-measured weekday sleep onset and midpoint were associated with a higher body mass index (respective β-estimates: −0.63, p < 0.01 and −0.75, p < 0.01) and waist-to-height ratio (−0.004, p = 0.03 and −0.01, p = 0.02). Though the sleep estimation methods were consistent and correlated, actigraphy measures should be favoured as they are more objective and sensitive to identifying associations between sleep timing and weight status compared with parent reports.
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- Ahlström, Christer, 1977-, et al.
(författare)
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Development of sleepiness in professional truck drivers : Real‐road testing for driver drowsiness and attention warning (DDAW) system evaluation
- 2024
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Ingår i: Journal of Sleep Research. - : John Wiley & Sons. - 0962-1105 .- 1365-2869.
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Tidskriftsartikel (refereegranskat)abstract
- All new vehicle types within the European Union must now be equipped with a driver drowsiness and attention warning system starting from 2022. The specific requirements for the test procedure necessary for type approval are defined in the Annex of EU Regulation C/2021/2639. The objectives of this study were to: (i) investigate how sleepiness develops in professional truck drivers under real-road driving conditions; and (ii) assess the feasibility of a test procedure for validating driver drowsiness and attention warning systems according to the EU regulation. Twenty-four professional truck drivers participated in the test. They drove for 180 km on a dual-lane motorway, first during daytime after a normal night's sleep and then at nighttime after being awake since early morning. The results showed higher sleepiness levels during nighttime driving compared with daytime, with a faster increase in sleepiness with distance driven, especially during the night. Psychomotor vigilance task results corroborated these findings. From a driver drowsiness and attention warning testing perspective, the study design with sleep-deprived drivers at night was successful in inducing the targeted sleepiness level of a Karolinska Sleepiness Scale score of ≥ 8. Many drivers who reported a Karolinska Sleepiness Scale ≥ 8 during the drives also acknowledged feeling sleepy in the post-drive questionnaire. Reaching high levels of sleepiness on real roads during daytime is more problematic, not the least from legal and ethical perspectives as higher traffic densities during the daytime lead to increased risks.
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| 4. |
- Ahlström, Christer, 1977-, et al.
(författare)
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Local changes in the wake electroencephalogram precedes lane departures
- 2017
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Ingår i: Journal of Sleep Research. - : Blackwell Publishing. - 0962-1105 .- 1365-2869. ; 26:6, s. 816-819
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this exploratory study is to investigate if lane departures are associated with local sleep, measured via source-localized electroencephalography (EEG) theta power in the 5-9 Hz frequency range. Thirty participants drove in an advanced driving simulator, resulting in 135 lane departures at high levels of self-reported sleepiness. These lane departures were compared to matching non-departures at the same sleepiness level within the same individual. There was no correspondence between lane departures and global theta activity. However, at the local level an increased risk for lane departures was associated with increased theta content in brain regions related to motor function.
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| 5. |
- Ahlström, Christer, 1977-, et al.
(författare)
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The effect of daylight versus darkness on driver sleepiness : A driving simulator study
- 2017
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Ingår i: Journal of Sleep Research. - : Wiley-Blackwell Publishing Inc.. - 0962-1105 .- 1365-2869.
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Tidskriftsartikel (refereegranskat)abstract
- Driver sleepiness studies are often carried out with alert drivers during daytime and sleep-deprived drivers during night-time. This design results in a mixture of different factors (e.g. circadian effects, homeostatic effects, light conditions) that may confound the results. The aim of this study was to investigate the effect of light conditions on driver sleepiness. Thirty young male drivers (23.6 ± 1.7 years old) participated in a driving simulator experiment where they drove on a rural road. A 2 × 2 design was used with the conditions daylight versus darkness, and daytime (full sleep) versus night-time (sleep deprived). The results show that light condition had an independent effect on the sleepiness variables. The subjective sleepiness measured by Karolinska Sleepiness Scale was higher, lateral position more left-oriented, speed lower, electroencephalogram alpha and theta higher, and blink durations were longer during darkness. The number of line crossings did not change significantly with light condition. The day/night condition had profound effects on most sleepiness indicators while controlling for light condition. The number of line crossings was higher during night driving, Karolinska Sleepiness Scale was higher, blink durations were longer and speed was lower. There were no significant interactions, indicating that light conditions have an additive effect on sleepiness. In conclusion, Karolinska Sleepiness Scale and blink durations increase primarily with sleep deprivation, but also as an effect of darkness. Line crossings are mainly driven by the need for sleep and the reduced alertness at the circadian nadir. Lane position is, however, more determined by light conditions than by sleepiness.
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| 6. |
- Ahlström, Christer, 1977-, et al.
(författare)
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The impact of driver sleepiness on fixation-related brain potentials
- 2020
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Ingår i: Journal of Sleep Research. - : Wiley. - 0962-1105 .- 1365-2869. ; 29:5
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Tidskriftsartikel (refereegranskat)abstract
- The effects of driver sleepiness are often quantified as deteriorated driving performance, increased blink durations and high levels of subjective sleepiness. Driver sleepiness has also been associated with increasing levels of electroencephalogram (EEG) power, especially in the alpha range. The present exploratory study investigated a new measure of driver sleepiness, the EEG fixation-related lambda response. Thirty young male drivers (23.6 +/- 1.7 years old) participated in a driving simulator experiment in which they drove on rural and suburban roads in simulated daylight versus darkness during both the daytime (full sleep) and night-time (sleep deprived). The results show lower lambda responses during night driving and with longer time on task, indicating that sleep deprivation and time on task cause a general decrement in cortical responsiveness to incoming visual stimuli. Levels of subjective sleepiness and line crossings were higher under the same conditions. Furthermore, results of a linear mixed-effects model showed that low lambda responses are associated with high subjective sleepiness and more line crossings. We suggest that the fixation-related lambda response can be used to investigate driving impairment induced by sleep deprivation while driving and that, after further refinement, it may be useful as an objective measure of driver sleepiness.
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| 8. |
- Ahonen, Hanna, et al.
(författare)
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"The terrible dryness woke me up, I had some trouble breathing"-Critical situations related to oral health as described by CPAP-treated persons with obstructive sleep apnea
- 2022
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Ingår i: Journal of Sleep Research. - : John Wiley & Sons. - 0962-1105 .- 1365-2869. ; 31:6
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Tidskriftsartikel (refereegranskat)abstract
- Continuous positive airway pressure is a common and effective treatment for obstructive sleep apnea, but adherence remains an issue. Both obstructive sleep apnea and oral diseases are associated with cardiovascular diseases, and as oral dryness contributes to treatment abandonment, oral health is of importance for this patient group. The aim was therefore to explore how persons with continuous positive airway pressure-treated obstructive sleep apnea experience situations associated with their oral health, and which actions they take to manage these. An explorative and descriptive design was adopted using the critical incident technique. Based on a purposeful selection, 18 adults with long-term experience of continuous positive airway pressure-treatment were interviewed using a semi-structured interview guide. Both negative and positive situations were described. Negative situations consisted of challenges with breathing, including mouth-breathing, choking sensations, problems with night-time and daytime oral dryness, changes in the saliva composition, and deteriorating oral health. Positive situations included experiences of reduced mouth-breathing and oral dryness. The situations were often successfully managed by mimicking daytime movements, changing sleeping position, adjusting the CPAP-device and mask, increasing oral hygiene efforts, drinking water, using a humidifier or chinstrap, or contacting their oral healthcare clinic. Long-term experience of persons with continuous positive airway pressure-treated obstructive sleep apnea regard situations and actions from everyday life. Successful management can contribute to long-term adherence and decrease negative effects on oral health. More interdisciplinary collaborations could enable identification and adequate recommendations for persons who experience negative situations during their continuous positive airway pressure treatment.
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