Peter Westerholm

Sleep disturbances, work stress and work hours: A cross-sectional study

OBJECTIVEnThe study examined the multivariate relationship between disturbed sleep and different work-related and background/life style factors.nnnMETHODSn5720 healthy employed men and women living in the greater Stockholm area participated. A factor analysis of eight items provided one main factor: disturbed sleep. The data were analyzed using a multiple logistic regression analysis against the index disturbed sleep as well as the separate items not well rested and difficulties awakening.nnnRESULTSnThe results showed that high work demands [odds ratio (OR) = 2.15] and physical effort at work (OR = 1.94) are risk indicators for disturbed sleep, while high social support is associated with reduced risk (OR = 0.44). In addition, higher age (45+), female gender, a high body mass index (BMI) and lack of exercise are background/life style risk indicators. Introducing into the model an item representing inability to stop thinking about work during free time yielded the highest OR (3.20) and forced work demands out of the regression. With regard to not feeling well rested, the same significant predictors, except physical effort, were obtained, as well as for having night work and being married. In addition, the age effect was reversed--high age predicted reduced risk of not feeling well rested. Difficulties awakening was predicted by high work demands, low social support, being male, low age and smoking. It is notable that, whereas subjective sleep quality decreased with age, the difficulties awakening and feelings of not being well rested after sleep increased with age.nnnCONCLUSIONnIt was concluded that stress and the social situation at work are strongly linked to disturbed sleep and impaired awakening, that gender and, even more so, age may modify this and that the inability to stop worrying about work during free time may be an important link in the relation between stress and sleep.

Work organisation and unintentional sleep: results from the WOLF study

Background: Falling asleep at work is receiving increasing attention as a cause of work accidents. Aims: To investigate which variables (related to work, lifestyle, or background) are related to the tendency to fall asleep unintentionally, either during work hours, or during leisure time. Methods: 5589 individuals (76% response rate) responded to a questionnaire. A multiple logistic regression analysis of the cross sectional data was used to estimate the risk of falling asleep. Results: The prevalence for falling asleep unintentionally at least once a month was 7.0% during work hours and 23.1% during leisure time. The risk of unintentional sleep at work was related to disturbed sleep, having shift work, and higher socioeconomic group. Being older, being a woman, and being a smoker were associated with a reduced risk of unintentionally falling asleep at work. Work demands, decision latitude at work, physical load, sedentary work, solitary work, extra work, and overtime work were not related to falling asleep at work. Removing “disturbed sleep” as a predictor did not change the odds ratios of the other predictors in any significant way. With respect to falling asleep during leisure time, disturbed sleep, snoring, high work demands, being a smoker, not exercising, and higher age (>45 years) became risk indicators. Conclusion: The risk of involuntary sleep at work is increased in connection with disturbed sleep but also with night work, socioeconomic group, low age, being a male, and being a non-smoker.

Occurrence of pleural plaques in workers with exposure to mineral wool

The objective of this study was to investigate whether occurrence of pleural plaques is associated with exposure to mineral wool. The occurrence of pleural plaques on routine chest radiographs of 933 persons employed in the mineral wool manufacturing industry and 865 referents was compared. Twelve men from the mineral wool industry had pleural plaques, as against three of the referents (P > 0.05). The occurrence of pleural plaques among men in the mineral wool industry was not associated with an increased exposure to mineral wool or with length of time between start of employment and time of chest radiograph. The results do not support the notion that inhalation of man-made mineral fibers causes pleural plaques. It must, however, be conceded-keeping in mind the limits imposed by the study size-that nor do they provide grounds for refutation of such a hypothesis.

Work overcommitment: Is it a trait or a state?

PurposeEffort–reward imbalance (ERI) is a well-tested work-related stress model with three components, the two extrinsic components “efforts” and “rewards” and the one intrinsic component “overcommitment”. While an imbalance between “efforts” and “rewards” leads to strain reactions, “work-related overcommitment” (OC) has been described as a personal characteristic with a set of attitudes, behaviours, and emotions reflecting excessive striving combined with a strong desire for approval. However, the question whether OC is a personality trait or a response pattern sensitive to changes in the work context (state) is still open.Methods2940 Swedish industrial employees were included in this longitudinal analysis of the WOLF-Norrland data over 5 years. A change of OC index or its subscales were regressed against a change of freedom of choice at work, extra work, and ERI adjusted for age, sex, and education.ResultsWhile OC was insensitive to changes in freedom of choice at work and extra work, it was clearly associated with changes of work-related stress over time. Three of four OC subscales exhibited statistically significant associations with ERI.ConclusionsFor the first time, we studied fundamental characteristics of OC as an independent personality variable (trait) or an outcome variable subject to changes in the work environment (state). The association between external ERI and OC over time supports our hypothesis of OC being a state. Further investigations are needed to establish OC as a trait or a state.

Long working hours and cancer risk: a multi-cohort study.

Overtime work and long working hours are associated with an increased risk of many adverse health outcomes, such as coronary heart disease and stroke. However, the relationship of excess working hours with incident cancer is unclear. To address this gap in the knowledge, we examined the association between weekly working hours and cancer risk using individual-participant data from 12 prospective studies from Denmark, Finland, Germany, Sweden, the Netherlands and the UK.Our analyses were based on data from 116 462 working men and women, who were free of cancer at study baseline. Incident cancers were ascertained from national cancer, hospitalisation and death registers. Weekly working hours were self-reported. During a follow-up ranging from 4 to 22 years, 4 371 participants were diagnosed with cancer (n colorectal cancer: 393, n lung cancer: 247, n breast cancer: 833, n prostate cancer: 534). Compared to standard working time (35–40 hours/week), working >55 hours/week was not associated with the overall cancer incidence (multivariable-adjusted HR (95% CI): 1.00 (0.85, 1.16). Similarly, working hours were unrelated to incident colorectal, lung and prostate cancers. Compared to standard hours, working >55 hours/week was associated with 1.60-fold (95% CI: 1.12–2.29) risk of female breast cancer. This association was independent of age, socioeconomic position, shift- and night-time work and lifestyle factors, but it may have been influenced by residual confounding from parity. To our knowledge, ours is the largest investigation of this topic to-date and the first to examine the association of working hours with the overall cancer risk and the risk of specific cancers. Our findings suggest that working long hours is not a risk factor for cancer in general, or lung, colorectal or prostate cancers in particular. The observed association with breast cancer would warrant further research.

Fatigue/sleepiness and important aspects of sleep restoration improve across aging

Objective: The aim of this study was to describe the prevalence and characteristics of periodic legs movements of sleep (PLMS) in theadult general population. Methods: Data from 2162 subjects (51.2% women, mean SD age:58, 11 years, range: 40.5-84.4 years) participating in a population-based cohort study (HypnoLaus, Lausanne, Switzerland) wascollected. They completed a series of sleep related questionnaires and underwent polysomnographic recordings at home. PLMS index(PLMSI) was determined according to AASM 2007 criteria. APLMSI>15/h was considered to be of potential clinical significance.nConclusions: PLMS are highly prevalent in the general population. Age, male gender and RLS are independent predictors of a PLMSIhigher than 15/h. Further studies are needed to evaluate the clinical impact of PLMS.16 Social burden and management of sleep disorders P. Jennum Danish Center for Sleep Medicine, Department of Clinical Neurophysiology Glostrup Hospital, University of Copenhagen, Copenhagen, Denmark Sleep disorders, such as insomnias, obstructive sleep apnoea, and central hypersomnias (narcolepsy, idiopathic hypersomnia), short sleep or sleep loss, and restless leg syndrome, are common disorders or complaints with a significant healthcare burden with consequences for healthcare contacts, medication use, education, employment and the risk of traffic accidents. There is now compelling evidence that the health-related (direct) and social (indirect) costs are significant, and comparable to those of other major disease areas. Thus, in order to care properly for patients presenting with sleeprelated morbidity, and to reduce the consequential economic burden, accurate screening efforts and effective, cost-effective treatments need to be developed and employed. Disclosure: Nothing to disclose.Objective: There is limited knowledge about the prospective relation between work characteristics (stress, physical work environment, work hours) and disturbed sleep. The present study sought to provide such knowledge. Method: The study was based on self-rated questionnaire data from two waves of the SLOSH cohort, The Swedish Longitudinal Occu- pational Survey of Health, an approximately representative sample of the working population in Sweden. In total, 5741 persons (54% women, age 24–72, gainfully employed at both waves) were included in the analyses. Results: Work-related factors at T1 (e.g. work demands, control, social support, physical work environment, work hours and stress) were analyzed with logistic regression with sleep disturbances at T2 as the outcome. Work demands (OR 95% CI, 1.57; 1.28–1.93) and stress (1.51; 1.27–1.85) at T1 predicted sleep disturbances at T2. When the work related predictors from T1 and T2 were combined, persistent high work demands and stress levels related to disturbed sleep at T2, as did an increase in stress and decrease in social support. A reverse relation between disturbed sleep at T1 and stress and high work demands at T2 was also found, suggesting a bidirectional relationship. Neither shift work, long hours, heavy physical work, noise at work, nor poor lighting conditions predicted disturbed sleep. Conclusions: Psychosocial risk factors at work related to subse- quent self-reported disturbed sleep, but long hours, shift work and physical work environment variables did not. The results are important for understanding the role of work factors in sleep disturbances. Disclosure: Nothing to disclose.