Wessel van LeeuwenForskningsassistent
Wessel van Leeuwen (MSc. i neurovetenskap ifrån Vrije Universiteit Amsterdam) är forskningsassistent hos enheten för sömn- och vakenhetsforsking. Hans forskningsprojekt handlar mest om sömn, sömnighet, trötthet och stress hos dem som arbetar i transportsektorn och innebär både simulator- och fältstudier. Han har samarbetat och samarbetar bland annat med Warsash Maritime Academy i Storbritannien, Dalian Maritime University i Kina och the University of Southern Denmark. Mer information om Wessel hittas bland annat på hans LinkedIn profil och Twitter konto.
Wessel är kursledare på masterkursen Stress, återhämtning och hälsa (7,5 hp) inom masterprogrammet Population health: Societal and individual perspectives hos Institutionen för Folkhälsovetenskap.
I urval från Stockholms universitets publikationsdatabas
Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men
2018. Wessel M. A. van Leeuwen (et al.). Sleep and Biological Rhythms 16 (1), 45-54Artikel
Sleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men.
After two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed.
In the control group, none of the parameters changed. In the experimental group, heart rate increased from 60 ± 1.8 beats per minute (bpm) at BL, to 63 ± 1.1 bpm after SR and further to 65 ± 1.8 bpm after REC. In addition, whole day low-frequency to-high frequency (LF/HF) power ratio of heart rate variability increased from 4.6 ± 0.4 at BL to 6.0 ± 0.6 after SR. Other parameters, including salivary NPY and cortisol levels, remained unaffected.
Increased heart rate and LF/HF power ratio are early signs of an increased sympathetic activity after prolonged sleep restriction. To reliably interpret the clinical significance of these early signs of physiological stress, a follow-up study would be needed to evaluate if the stress responses escalate and lead to more unfavourable reactions, such as elevated blood pressure and a subsequent elevated risk for cardiovascular health problems.
Does sleep deprivation increase the vulnerability to acute psychosocial stress in young and older adults?
2018. Johanna Schwarz (et al.). Psychoneuroendocrinology 96, 155-165Artikel
Sleep loss and psychosocial stress often co-occur in today’s society, but there is limited knowledge on the combined effects. Therefore, this experimental study investigated whether one night of sleep deprivation affects the response to a psychosocial challenge. A second aim was to examine if older adults, who may be less affected by both sleep deprivation and stress, react differently than young adults. 124 young (18–30 years) and 94 older (60–72 years) healthy adults participated in one of four conditions: i. normal night sleep & Placebo-Trier Social Stress Test (TSST), ii. normal night sleep & Trier Social Stress Test, iii. sleep deprivation & Placebo-TSST, iv. sleep deprivation & TSST. Subjective stress ratings, heart rate variability (HRV), salivary alpha amylase (sAA) and cortisol were measured throughout the protocol. At the baseline pre-stress measurement, salivary cortisol and subjective stress values were higher in sleep deprived than in rested participants. However, the reactivity to and recovery from the TSST was not significantly different after sleep deprivation for any of the outcome measures. Older adults showed higher subjective stress, higher sAA and lower HRV at baseline, indicating increased basal autonomic activity. Cortisol trajectories and HRV slightly differed in older adults compared with younger adults (regardless of the TSST). Moreover, age did not moderate the effect of sleep deprivation. Taken together, the results show increased stress levels after sleep deprivation, but do not confirm the assumption that one night of sleep deprivation increases the responsivity to an acute psychosocial challenge.
Risk Factors for Fatigue in Shipping, the Consequences for Seafarers’ Health and Options for Preventive Intervention
2017. Jørgen Riis Jepsen (et al.). Maritime Psychology, 127-150Kapitel
The consequences of fatigue for the health and safety of seafarers have caused concern in the industry and among academics, and indicates the importance of further research into risk factors and preventive interventions at sea. This chapter gives an overview of the key issues relating to seafarer fatigue. A literature study was conducted aimed at collecting publications that address risk factors for fatigue, short-term and long-term consequences for health and safety, and options for fatigue mitigation at sea. Due to the limited number of publications that deal with seafarers, experiences from other populations sharing the same exposures (e.g. shift work) were also included when appropriate. Work at sea involves multiple risk factors for fatigue, which in addition to acute effects (e.g. impaired cognition, accidents) contributes through autonomic, immunologic and metabolic pathways to the development of chronic diseases that are particularly prevalent in seafarers. Taking into account the frequency of seafarer fatigue and the severity of its consequences, the efficacy of the current legislative framework and the industry’s compliance, the manning of the international merchant fleet, and optimized working, living and sleeping conditions at sea all need serious reconsideration. Given the circumstances at sea which cannot be altered, e.g. working in shifts and crossing time zones, further assessment of the potentials of preventive interventions including fatigue prediction tools and individual Fatigue Risk Management Systems (FRMS) is recommended.
2017. Margareta Lutzhoft (et al.). Simulators for Transportation Human FactorsKapitel
Simulation continues to be a growth area in transportation human factors. From empirical studies in the laboratory to the latest training techniques in the field, simulators offer myriad benefits for the experimenter and the practitioner. This book draws together current trends in research and training simulators for the road, rail, air and sea sectors to inform the reader how to maximize both validity and cost-effectiveness in each case. Simulators for Transportation Human Factors provides a valuable resource for both researchers and practitioners in transportation human factors on the use of simulators, giving readers concrete examples and case studies of how simulators have been developed and used in empirical research as well as training applications. It offers useful and usable information on the functional requirements of simulators without the need for any background knowledge on the technical aspects, focusing on the state of the art of research and applications in transport simulators rather than the state of the art of simulation technology. The book covers simulators in operational terms instead of task simulation/modelling and provides a useful balance between a bottom-up, academic approach and a top-down, practical perspective.
Countermeasures for fatigue in transportation
2015. Anna Anund (et al.).Rapport
2015. Jørgen Riis Jepsen, Zhiwei Zhao, Wessel M. A. van Leeuwen. International Maritime Health 66 (2), 106-117Artikel
Background: The consequences of fatigue for the health and safety of seafarers has caused concern in the industry and among academics, and indicates the importance of further research into risk factors and preventive interventions at sea. This review gives an overview of the key issues relating to seafarer fatigue.
Materials and methods: A literature study was conducted aiming to collect publications that address risk factors for fatigue, short-term and long-term consequences for health and safety, and options for fatigue mitigation at sea. Due to the limited number of publications that deals with seafarers, experiences from other populations sharing the same exposures (e.g. shift work) were also included when appropriate.
Results: Work at sea involves multiple risk factors for fatigue, which in addition to acute effects (e.g., impaired cognition, accidents) contributes through autonomic, immunologic and metabolic pathways to the development of chronic diseases that are particularly prevalent in seafarers.
Conclusions: Taking into account the frequency of seafarer fatigue and the severity of its consequences, one should look into the efficacy of the current legislative framework and the industry’s compliance, the manning of the international merchant fleet, and optimised working, living and sleeping conditions at sea. Considering circumstances at sea, e.g. working in shifts and crossing time zones, that cannot be altered, further assessment of the potentials of preventive interventions including fatigue prediction tools and individual fatigue mitigation management systems is recommended.
Sleep, Sleepiness, and Neurobehavioral Performance While on Watch in a Simulated 4 Hours on/8 Hours off Maritime Watch System
2013. Wessel M A van Leeuwen (et al.). Chronobiology International 30 (9), 1108-1115Artikel
Seafarer sleepiness jeopardizes safety at sea and has been documented as a direct or contributing factor in many maritime accidents. This study investigates sleep, sleepiness, and neurobehavioral performance in a simulated 4 h on/8 h off watch system as well as the effects of a single free watch disturbance, simulating a condition of overtime work, resulting in 16 h of work in a row and a missed sleep opportunity. Thirty bridge officers (age 30 ± 6 yrs; 29 men) participated in bridge simulator trials on an identical 1-wk voyage in the North Sea and English Channel. The three watch teams started respectively with the 00-04, the 04-08, and the 08-12 watches. Participants rated their sleepiness every hour (Karolinska Sleepiness Scale [KSS]) and carried out a 5-min psychomotor vigilance test (PVT) test at the start and end of every watch. Polysomnography (PSG) was recorded during 6 watches in the first and the second half of the week. KSS was higher during the first (mean ± SD: 4.0 ± 0.2) compared with the second (3.3 ± 0.2) watch of the day (p < 0.001). In addition, it increased with hours on watch (p < 0.001), peaking at the end of watch (4.1 ± 0.2). The free watch disturbance increased KSS profoundly (p < 0.001): from 4.2 ± 0.2 to 6.5 ± 0.3. PVT reaction times were slower during the first (290 ± 6 ms) compared with the second (280 ± 6 ms) watch of the day (p < 0.001) as well as at the end of the watch (289 ± 6 ms) compared with the start (281 ± 6 ms; p = 0.001). The free watch disturbance increased reaction times (p < 0.001) from 283 ± 5 to 306 ± 7 ms. Similar effects were observed for PVT lapses. One third of all participants slept during at least one of the PSG watches. Sleep on watch was most abundant in the team working 00-04 and it increased following the free watch disturbance. This study reveals that-within a 4 h on/8 h off shift system-subjective and objective sleepiness peak during the night and early morning watches, coinciding with a time frame in which relatively many maritime accidents occur. In addition, we showed that overtime work strongly increases sleepiness. Finally, a striking amount of participants fell asleep while on duty.