| 1. |
- Amnå, Erik, et al.
(författare)
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En halv miljard av statens pengar riskerar att slösas bort
- 2007
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Ingår i: Göteborgs-Posten. ; 2007-09-13, s. 47-47
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Minskade anslag gör att den årliga undersökningen om våra levnadsförhållanden hotas att halveras. Det kan drabba redan svaga grupper som äldre, invandrare och ensamstående föräldrar.
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| 2. |
- Anund, Anna, et al.
(författare)
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Driver impairment at night and its relation to physiological sleepiness.
- 2008
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Ingår i: Scand J Work Environ Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 34:2, s. 142-50
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Tidskriftsartikel (refereegranskat)abstract
- Driver impairment at night and its relation to physiological sleepiness.Anund A, Kecklund G, Peters B, Forsman A, Lowden A, Akerstedt T.VTI, S-581 95 Linköping, Sweden. anna.anund@vti.se.OBJECTIVES: Studies of devices detecting sleepiness need reference points of physiological sleepiness. The present study sought to validate the Karolinska drowsiness score (KDS) as an indicator of physiological sleepiness against driving impairment and eye blink duration during a 45-minute drive in an advanced moving-base driving simulator. METHODS: Data from 19 persons were used in the analysis. Electrooculography, electroencephalography, and electromyography were administered continuously. Physiological sleepiness was quantified by scoring the percentage (0-100%) of the scoring epoch with alpha and theta activity and slow eye movements (KDS). Lateral position and speed were used as measures of driving behavior. Lane departure was defined as two wheels touching the lane markers. Blink duration was used as a secondary indicator of sleepiness. RESULTS: The results showed that, for young drivers, sleepiness increased with time in the task with higher levels. The variability of the lateral position and the mean and variability of the blink duration significantly changed when sleepiness increased to KDS >/=20%. Furthermore, there was an increase in the risk of lane departure for KDS >/=30%. CONCLUSIONS: The results suggest that KDS scoring is a reasonable procedure for estimating physiological sleepiness under conditions of driving. The results also indicate that a younger age is associated with greater sensitivity to sleepiness at the wheel.
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| 3. |
- Anund, Anna, et al.
(författare)
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The effects of driving situation on sleepiness indicators after sleep loss : A driving simulator study
- 2009
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Ingår i: Industrial Health. - : National Institute of Industrial Health. - 0019-8366 .- 1880-8026. ; 47:4, s. 393-401
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Tidskriftsartikel (refereegranskat)abstract
- Almost all studies of sleepy driving are carried out in driving simulators and with monotonous road conditions (no interaction with other cars). The present study investigated indicators of sleepy driving in a more challenging scenario after a night awake. 17 participants drove a high fidelity moving base driving simulator experiment while sleepiness was monitored physiologically and behaviourally. Short periods of situations of free driving (no other vehicles) alternated with short periods of following another vehicle (car following) with and without the possibility to overtake. The result showed that a night of prior sleep loss increased sleepiness levels at the wheel (eye closure duration and lateral variability) compared to after a night of normal sleep. Blink duration while overtaking was significantly lower compared to the other situations, it was at the same level as after night sleep. Speed when passing a stopped school bus was not significantly affected by sleepiness. However the warning caused a more rapid reduction of speed. In conclusion, a moderately challenging driving contest did not affect sleepiness indicators, but a very challenging one did so (overtaking). This suggests that it is important to monitor the driving situation in field operational tests of sleepy driving.
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| 4. |
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| 5. |
- Arnetz, Bengt B., et al.
(författare)
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The Effects of 884 MHz GSM Wireless Communication Signals on Self-reported Symptoms and Sleep : An Experimental Provocation Study
- 2007
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Ingår i: PIERS online. - 1931-7360. ; 3:7, s. 1148-1150
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Tidskriftsartikel (refereegranskat)abstract
- In the current study we assessed possible effects of prolonged (3 hours) exposure to 884 MHz GSM wireless communication signals on self-reported symptoms, cognitive function, and electroencephalographically (EEG) recorded sleep. The study group consisted of 36 women and 35 men. Twenty-two women and sixteen men reported symptoms they specifically related to mobile phone use (SG). The rest of the participants reported no mobile phone-related symptoms (NG). Potential participants volunteering for the study were evaluated by physicians, including some biochemical assessments, to rule out medical conditions that could interfere with study variables of interest. Once selected, participants spent three different sessions in the laboratory. The habituation session was followed by two subsequent sessions. In these subsequent sessions, subjects were either exposed to sham exposure (sham) or 884 MHz GSM wireless communication signals for 3 hours (an average of 1.4 W/kg including periods of DTX and Non-DTX. Exposure directed to the left hemisphere). Data was collected before, during and following the exposure/sham sessions. Data collected included self-reported symptoms, including headache, cognitive function, mood, and electroencephalographic recordings. During actual exposure, as compared to sham exposure, sleep initiated one hour after exposure was affected. There was a prolonged latency to reach the first cycle of deep sleep (stage 3). The amount of stage 4 sleep was also decreased in exposed subjects. NG subjects reported more headaches during exposures vs. sham exposure. Neither group (SG and NG) was able to detect the true exposure status more frequently than by chance alone. The study indicates that during laboratory exposure to 884 MHz wireless signals, components of sleep, believed to be important for recovery from daily wear and tear, are adversely affected. Moreover, participants that otherwise have no self-reported symptoms related to mobile phone use, appear to have more headaches during actual radiofrequency exposure as compared to sham exposure. However, subjects were not able to detect the true exposure status more often than would have been expected by statistical chance alone. Additional self-reported findings, biochemical, performance and electrophysiological data are currently being analyzed. Possible health implications from the findings will also be further explored.
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| 6. |
- Axelsson, John, et al.
(författare)
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Effects of acutely displaced sleep on testosterone.
- 2005
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Ingår i: J Clin Endocrinol Metab. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 90:8, s. 4530-5
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: It is not yet clear whether the diurnal variation in testosterone is regulated by circadian or homeostatic (sleep) influences. OBJECTIVE: The present study tested whether testosterone is driven by a circadian-independent sleep effect by shifting sleep acutely to daytime in a 24-h sampling regiment. DESIGN, SETTING, AND PARTICIPANTS: In the sleep laboratory, seven healthy young men (age, 22-32 yr) participated in three conditions: habituation (sleep between 2300-0700 h), night sleep (2300-0700 h), and day sleep (0700-1500 h), the latter two in a balanced order. INTERVENTION AND MAIN OUTCOME MEASURE: Serum testosterone was, in all conditions, sampled by hourly blood drawing for 24 h during constant bed rest. RESULTS: Mean testosterone levels increased as a log-linear function of time (hours) across both sleep periods (b = 4.88; P < 0.001), from 15.3 +/- 2.1 to 25.3 +/- 2.2 nmol/liter during night sleep and from 17.3 +/- 2.1 to 26.4 +/- 2.9 nmol/liter during day sleep. Similarly, mean testosterone levels decreased with time (log-linear) awake (b = -1.80; P < 0.001). There was also evidence of a weak circadian component (acrophase ranging between 0651-0924 h) and an increase with time in the laboratory. Moreover, all these effects, except for the increase during sleep, differed significantly between individuals. CONCLUSION: In conclusion, testosterone increased during sleep and fell during waking, whereas circadian effects seemed marginal. Individual differences were pronounced.
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| 7. |
- Axelsson, John, 1969-
(författare)
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Long shifts, short rests and vulnerability to shift work
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- At the same time as many urban economies are developing into 24-hour societies it is becoming increasingly popular amongst shift workers to compress their working hours. This is done by working longer shifts (>8h) and/or restricting free time (<16h) in between shifts – the main reasons are to gain longer bouts of free time and extra free weekends. However, there is a limited knowledge of the effects of such arrangements on sleep and wakefulness. Thus, the main purposes of the present thesis were to evaluate the effects of long working hours (in the form of 12h shifts) and short recovery periods. Another aim was to evaluate possible mechanisms that could suggest why some individuals develop problems with shift work while others do not.We used a combination of methods - sleep diaries, wake diaries, blood samples and objective measures of sleep and cognitive performance - across whole or large parts of shift schedules to evaluate acute effects of particularly demanding working periods, as well as the total effects of a shift cycle. Study I evaluated the effect of changing from an 8h- to a 12h-shift system. Study II evaluated the effects of long shifts in a shift schedule with both 8h- and 12h-shifts. Study III evaluated the effects of several consecutive short recovery periods (8-9h of recovery) and whether satisfaction with ones’ work hours was associated to problems with sleep and sleepiness. Study IV evaluated whether endocrinological markers of catabolic (cortisol) and anabolic (testosterone) activity changed across a shift sequence and whether satisfaction were related to them. Study V was a laboratory simulation of the effects of a short recovery period (4h of sleep) and whether a short nap could counteract any detrimental effects.There was no convincing evidence for 12h shifts inducing more problems with sleep and sleepiness than 8h shifts. With regard to recovery time between shifts, the shortest recovery times (only 8h) seriously shortened sleep duration and increased sleepiness, while 12h of recovery (between two consecutive 12h shifts) was judged as having no or limited effects on acute measures. The problems with the shortest recovery periods were worse in a schedule with several consecutive shifts and less pronounced in a schedule with few consecutive shifts. With regard to individual differences, it was found that subjects being dissatisfied with their working hours were vulnerable to short recovery periods, which was evident by less sufficient sleep and an accumulation of sleepiness across work periods with limited recovery time. Interestingly, these problems disappeared when they were allowed to recover after the work period. In addition, dissatisfied male shift workers had lower testosterone levels at the end of work periods, indicating disturbed anabolic activity. The simulated quick return supported that curtailed sleep affected sleepiness and performance and that a short nap could counteract these effects temporarily.It is concluded that long shifts (up to 12h) may be acceptable, whereas short recovery time (8h or less) is not. Most of the problems with short recovery periods were related to short sleep and sleepiness, and there is, clearly, a subgroup of workers that suffer more from this than others. It is argued that insufficient sleep and low testosterone levels (in males) might be key factors for developing shift intolerance, mainly by reducing the capacity to recover from shift work.
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| 8. |
- Dahlgren, Anna, et al.
(författare)
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Different levels of work-related stress and the effects on sleep, fatigue and cortisol
- 2005
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 31:4, s. 277-285
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The aim of the study was to relate different levels of work stress to measures of sleep and the diurnal pattern of salivary cortisol and subjective sleepiness. Methods Thirty-four white-collar workers participated under two different conditions. One workweek with a relatively high stress level (H) and one with a lower stress level (L) as measured through self-rated stress during workdays. The workers wore activity monitors, filled out a sleep diary, gave saliva samples (for cortisol), and rated their sleepiness and stress during one workday and one free day. Results During the week with stress the number of workhours increased and total sleep time decreased. Sleepiness showed a significant interaction between weeks and time of day, with particularly high levels towards the evenings of the stress week. Cortisol also showed a significant interaction, with a more flattened pattern, probably due to increased evening levels during the stress week. Stress (restlessness) at bedtime was significantly increased during the stress week. Conclusion The results demonstrate that a workweek with a high workload and much stress increases sleepiness and workhours, impairs sleep, and affects the pattern of diurnal cortisol secretion.
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| 9. |
- Dahlgren, Anna, et al.
(författare)
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Overtime work and its effects on sleep, sleepiness, cortisol and blood pressure in an experimental field study
- 2006
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 32:4, s. 318-327
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Previous studies of long workhours and their effects on stress, sleep, and health show inconclusive results. This inconclusiveness may be partly due to methodological problems such as the use of between-group designs or comparisons before and after reorganizations. In addition, stress is usually a confounder. A within-person design was used to examine the effects of working 8- or 12-hour shifts in the absence of additional stress. Methods In an experimental field study, 16 white-collar workers [9 women, mean age 45.9 (SD 15) years] undertook one workweek with normal workhours (8 hours) and 1 week of overtime with 4 extra hours of regular worktasks (12 hours). The participants wore actigraphs, rated sleepiness (Karolinska Sleepiness Scale) and stress throughout the day, and rated workload and how exhausted they felt. Saliva samples were collected on Mondays and Thursdays for cortisol analysis. On these days, ambulatory heart rate and blood pressure were also measured for 24 hours. Results Overtime was associated with higher levels of exhaustion. Sleepiness showed a significant interaction between conditions, with higher levels at the end of the workweek featuring overtime. Total sleep time was shorter in the overtime week. There were no significant differences between ratings of stress and workload. Cortisol showed a circadian variation but no main effect of condition. Conclusions One week of overtime work with a moderate workload produced no main effects on physiological stress markers. Nevertheless, sleep was negatively affected, with shorter sleeps during overtime work and greater problems with fatigue and sleepiness.
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| 10. |
- Dahlgren, Anna
(författare)
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Work stress and overtime work - effects on cortisol, sleep, sleepiness and health
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden the National Bureau of Statistics has reported an increase in stress-related disorders and sleep problems since the mid-1990’s. They also report that the number of hours of overtime worked has increased. Previous research on work-related stress and overtime work has demonstrated associations with altered physiological arousal, increased risk for stress related diseases, shorter sleep, greater fatigue and impaired performance. However, there is a lack of knowledge on the effects within individuals. The general aim of the thesis was to investigate the effect of overtime work and increased work stress on sleep, the diurnal pattern of cortisol, sleepiness and subjective stress in a within-subject design. In addition, it examined individual differences in the diurnal cortisol response to stress.We used a combination of methods – questionnaires, sleep and wake diaries, objective measures of sleep, stress hormones (salivary cortisol) and ambulatory measures of heart rate and blood pressure. Studies followed office workers during two different conditions of (I) high/low work stress and (II) overtime work respectively. The individual differences in the cortisol response to stress from study I prompted study III. In this study we examined two groups that showed different cortisol responses to stress.In conclusion, the results (I) demonstrated that a week with higher workload and stress affects physiological stress markers such as cortisol, and is associated with increased sleepiness and problems of unwinding at bedtime, shorter sleep duration and longer work hours. Furthermore (II) overtime work, under conditions of relatively low workload, was shown to be associated with modest effects on physiological markers of arousal. More pronounced effects were found on sleep and fatigue, with greater problems during overtime work. Study III indicated that individual differences in cortisol response to stress maybe related to fatigue and exhaustion.
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