Associations between systemic pro-inflammatory markers, cognitive function and cognitive complaints in a population-based sample of working adults.

BACKGROUND: The knowledge is limited regarding the relation between systemic inflammatory biomarkers and subjective and objective cognitive functioning in population-based samples of healthy adults across the adult age-span. Thus, the aim of this study was to study a selection of four pro-inflammatory biomarkers (IL-6, MCP-1, TNF-α, CRP) in relation to executive cognitive functioning, episodic memory and subjective cognitive complaints (SCC) in a population-based sample of 215 working adults (age 25-67). RESULTS: Higher levels of MCP-1 were associated with poorer executive cognitive functioning, even after adjustments for demographical factors, health status/conditions, SCC and depressive symptoms. IL-6 and CRP were associated with poorer executive cognitive functioning, but these associations covaried with age especially and were not present after adjustment for demographical factors. MCP-1 was associated with poorer episodic memory, but this association also covaried with age especially and was not present after adjustment for demographical factors, and CRP was associated with episodic memory only among participants without reported health conditions. Higher MCP-1 levels were also associated with more SCC and this association covaried with depressive symptoms, while higher levels of TNF-α were associated with less SCC. CONCLUSION: Low grade inflammatory processes in terms of higher systemic levels of pro-inflammatory biomarkers (MCP-1, IL-6 & CRP) were associated with poorer executive functioning in this sample of working adults, and MCP-1 was so after extensive adjustments. Support for associations between these biomarkers and episodic memory and SCC were more limited. Future research should address the causality of associations between low grade inflammatory processes and cognitive functioning.

Job strain as a risk factor for clinical depression: systematic review and meta-analysis with additional individual participant data.

BACKGROUND: Adverse psychosocial working environments characterized by job strain (the combination of high demands and low control at work) are associated with an increased risk of depressive symptoms among employees, but evidence on clinically diagnosed depression is scarce. We examined job strain as a risk factor for clinical depression. METHOD: We identified published cohort studies from a systematic literature search in PubMed and PsycNET and obtained 14 cohort studies with unpublished individual-level data from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium. Summary estimates of the association were obtained using random-effects models. Individual-level data analyses were based on a pre-published study protocol. RESULTS: We included six published studies with a total of 27 461 individuals and 914 incident cases of clinical depression. From unpublished datasets we included 120 221 individuals and 982 first episodes of hospital-treated clinical depression. Job strain was associated with an increased risk of clinical depression in both published [relative risk (RR) = 1.77, 95% confidence interval (CI) 1.47-2.13] and unpublished datasets (RR = 1.27, 95% CI 1.04-1.55). Further individual participant analyses showed a similar association across sociodemographic subgroups and after excluding individuals with baseline somatic disease. The association was unchanged when excluding individuals with baseline depressive symptoms (RR = 1.25, 95% CI 0.94-1.65), but attenuated on adjustment for a continuous depressive symptoms score (RR = 1.03, 95% CI 0.81-1.32). CONCLUSIONS: Job strain may precipitate clinical depression among employees. Future intervention studies should test whether job strain is a modifiable risk factor for depression.

Predictors of continued playing or singing--from childhood and adolescence to adult years.

AIM: Many individuals play an instrument or sing during childhood, but they often stop later in life. This study surveyed adults representative of the Swedish population about musical activities during childhood. METHODS: We asked 3820 adults (65% women) aged from 27 to 54 from the Swedish Twin Registry, who took extra music lessons to those provided at school, to fill in a web-based questionnaire. Factors analysed were the age they started studying music, the instrument they played, kind of teaching, institution and educational content, number of lessons and perceived characteristics of the lessons, the music environment during their childhood years and their preferred music genre. All variables were dichotomised. RESULTS: Factors strongly associated with continued playing or singing were male sex, young starting age, cultural family background, self-selected instrument, attending music classes and more than once a week, church-related or private education, pop, rock or classical music, playing by ear and improvisation. CONCLUSION: Several significant predictors determined whether a child continued to sing or play an instrument as an adult and many could be externally influenced, such as starting at a young age, taking music classes more than once a week, improvisation and the type of music they played.

Job strain and the risk of severe asthma exacerbations: a meta-analysis of individual-participant data from 100 000 European men and women.

BACKGROUND: Many patients and healthcare professionals believe that work-related psychosocial stress, such as job strain, can make asthma worse, but this is not corroborated by empirical evidence. We investigated the associations between job strain and the incidence of severe asthma exacerbations in working-age European men and women. METHODS: We analysed individual-level data, collected between 1985 and 2010, from 102 175 working-age men and women in 11 prospective European studies. Job strain (a combination of high demands and low control at work) was self-reported at baseline. Incident severe asthma exacerbations were ascertained from national hospitalization and death registries. Associations between job strain and asthma exacerbations were modelled using Cox regression and the study-specific findings combined using random-effects meta-analyses. RESULTS: During a median follow-up of 10 years, 1 109 individuals experienced a severe asthma exacerbation (430 with asthma as the primary diagnostic code). In the age- and sex-adjusted analyses, job strain was associated with an increased risk of severe asthma exacerbations defined using the primary diagnostic code (hazard ratio, HR: 1.27, 95% confidence interval, CI: 1.00, 1.61). This association attenuated towards the null after adjustment for potential confounders (HR: 1.22, 95% CI: 0.96, 1.55). No association was observed in the analyses with asthma defined using any diagnostic code (HR: 1.01, 95% CI: 0.86, 1.19). CONCLUSIONS: Our findings suggest that job strain is probably not an important risk factor for severe asthma exacerbations leading to hospitalization or death.

Work health determinants in employees without sickness absence.

BACKGROUND: Working ability is known to be related to good physical condition, clear work tasks, positive feedback and other occupational, organizational and psychosocial factors. In Sweden, high levels of sickness absence are due to stress-related disorders and musculoskeletal pain. AIMS: To identify work health characteristics in a working population with a large variety of professional skills and occupational tasks. METHODS: Employers' data on occupation, sickness absence, age and gender in a working population of 11 occupational groups and questionnaire responses regarding work-organization, environment, work stress, pain, health, and socio-demographic factors were collected. Employees with no history of sick-leave were compared with those with a history of sick-leave (1-182 days, mean 25 days). RESULTS: Of 2641 employees, 1961 participated. Those with no history of sick-leave reported less work-related pain, work-related stress, sleep disturbances, worry about their health, 'sick-presenteeism', monotonous work, bent and twisted working positions and exposure to disturbing noise than those with a history of sick-leave (P < 0.001). They also reported better health, support from superiors, having influence on their working hours and evening and week-end working, longer working hours per week (P < 0.001) and more regular physical training (P < 0.01). Socio-demographic factors were less important than gender, and differences in responses between occupational groups were also found. CONCLUSIONS: Workers without a history of sick-leave experienced less stress, sleep disturbances, worry about their own health and less neck, shoulder and back pain and more support from their superiors and influence on their working hours.

Job strain in relation to body mass index: pooled analysis of 160 000 adults from 13 cohort studies.

BACKGROUND: Evidence of an association between job strain and obesity is inconsistent, mostly limited to small-scale studies, and does not distinguish between categories of underweight or obesity subclasses. OBJECTIVES: To examine the association between job strain and body mass index (BMI) in a large adult population. METHODS: We performed a pooled cross-sectional analysis based on individual-level data from 13 European studies resulting in a total of 161 746 participants (49% men, mean age, 43.7 years). Longitudinal analysis with a median follow-up of 4 years was possible for four cohort studies (n = 42 222). RESULTS: A total of 86 429 participants were of normal weight (BMI 18.5-24.9 kg m(-2) ), 2149 were underweight (BMI < 18.5 kg m(-2) ), 56 572 overweight (BMI 25.0-29.9 kg m(-2) ) and 13 523 class I (BMI 30-34.9 kg m(-2) ) and 3073 classes II/III (BMI ≥ 35 kg m(-2) ) obese. In addition, 27 010 (17%) participants reported job strain. In cross-sectional analyses, we found increased odds of job strain amongst underweight [odds ratio 1.12, 95% confidence interval (CI) 1.00-1.25], obese class I (odds ratio 1.07, 95% CI 1.02-1.12) and obese classes II/III participants (odds ratio 1.14, 95% CI 1.01-1.28) as compared with participants of normal weight. In longitudinal analysis, both weight gain and weight loss were related to the onset of job strain during follow-up. CONCLUSIONS: In an analysis of European data, we found both weight gain and weight loss to be associated with the onset of job strain, consistent with a 'U'-shaped cross-sectional association between job strain and BMI. These associations were relatively modest; therefore, it is unlikely that intervention to reduce job strain would be effective in combating obesity at a population level.

Covert coping with unfair treatment at work and risk of incident myocardial infarction and cardiac death among men: prospective cohort study.

BACKGROUND: Covert coping with unfair treatment at work--occurring when an employee does not show the "aggressor" that he/she feels unfairly treated--has been found to be associated with cardiovascular risk factors. This study examined whether covert coping also predicts incident coronary heart disease. METHODS: A prospective cohort study (the WOLF Stockholm study) of workplaces in the Stockholm area, Sweden. The participants were 2755 men with no history of myocardial infarction at baseline screening in 1992-1995. The main outcome measure was hospitalisation due to myocardial infarction or death from ischaemic heart disease until 2003 obtained from national registers (mean follow-up 9.8 ± 0.9 years). RESULTS: Forty-seven participants had myocardial infarction or died from ischaemic heart disease during follow-up. After adjustment for age, socioeconomic factors, risk behaviours, job strain and biological risk factors at baseline, there was a dose-response relationship between covert coping and risk of incident myocardial infarction or cardiac death (p for trend=0.10). Men who frequently used covert coping had a 2.29 (95% CI 1.00 to 5.29) times higher risk than those who did not use coping. Restricting the analysis to direct coping behaviours only strengthened this association (p for trend=0.02). CONCLUSIONS: In this study, covert coping is strongly related to increased risk of hard-endpoint cardiovascular disease.

A prospective cohort study of deficient maternal nurturing attitudes predicting adulthood work stress independent of adulthood hostility and depressive symptoms.

Stressful childhood environments arising from deficient nurturing attitudes are hypothesized to contribute to later stress vulnerability. We examined whether deficient nurturing attitudes predict adulthood work stress. Participants were 443 women and 380 men from the prospective Cardiovascular Risk in Young Finns Study. Work stress was assessed as job strain and effort-reward imbalance in 2001 when the participants were from 24 to 39 years old. Deficient maternal nurturance (intolerance and low emotional warmth) was assessed based on mothers' reports when the participants were at the age of 3-18 years and again at the age of 6-21 years. Linear regressions showed that deficient emotional warmth in childhood predicted lower adulthood job control and higher job strain. These associations were not explained by age, gender, socioeconomic circumstances, maternal mental problems or participant hostility, and depressive symptoms. Deficient nurturing attitudes in childhood might affect sensitivity to work stress and selection into stressful work conditions in adulthood. More attention should be paid to pre-employment factors in work stress research.

Prevalence and characteristics of hearing problems in a working and non-working Swedish population.

BACKGROUND: Hearing problems are among the top 10 most common burdens of disease and are projected to be become even more common by the year 2030. The aim of the present study was to give a current assessment of the prevalence of communication difficulties because of hearing loss and tinnitus, in the general Swedish working and non-working populations in relation to sex, age, socioeconomic status (SES) and noise exposure. How prevalence is affected by SES has not been previously established. METHODS: A total of 18 734 individuals were invited to participate in the study, of which 11 441 (61%) enrolled. Of the participants, 9756 answered the questionnaire for those who work and 1685 answered the version for non-workers. FINDINGS: The most important findings are that 31% in the working population and 36% in the non-working population report either hearing loss or tinnitus or both. The prevalence of hearing problems increases with age, is higher among men and persons with low self-rated SES, and covaries with exposure to noise at work. Severe hearing problems are already present in men and women under 40 years of age who are exposed to work-related noise. INTERPRETATION: Prevalence of hearing problems is far more common than previously estimated and is associated with SES and noise exposure history. Hearing problems have a gradual onset that can take years to become recognised. In order to proactively intervene and prevent this deleterious, yet avoidable handicap, statistics need to be regularly updated.

Managerial leadership and ischaemic heart disease among employees: the Swedish WOLF study.

OBJECTIVE: To investigate the association between managerial leadership and ischaemic heart disease (IHD) among employees. METHODS: Data on 3122 Swedish male employees were drawn from a prospective cohort study (WOLF). Baseline screening was carried out in 1992-1995. Managerial leadership behaviours (consideration for individual employees, provision of clarity in goals and role expectations, supplying information and feedback, ability to carry out changes at work successfully, and promotion of employee participation and control) were rated by subordinates. Records of employee hospital admissions with a diagnosis of acute myocardial infarction or unstable angina and deaths from IHD or cardiac arrest to the end of 2003 were used to ascertain IHD. Cox proportional-hazards analyses were used to calculate hazard ratios for incident IHD per 1 standard deviation increase in standardised leadership score. RESULTS: 74 incident IHD events occurred during the mean follow-up period of 9.7 years. Higher leadership score was associated with lower IHD risk. The inverse association was stronger the longer the participant had worked in the same workplace (age-adjusted hazard ratio 0.76 (95% CI 0.61 to 0.96) for employment for 1 year, 0.77 (0.61 to 0.97) for 2 years, 0.69 (0.54 to 0.88) for 3 years, and 0.61 (0.47 to 0.80) for 4 years); this association was robust to adjustments for education, social class, income, supervisory status, perceived physical load at work, smoking, physical exercise, BMI, blood pressure, lipids, fibrinogen and diabetes. The dose-response association between perceived leadership behaviours and IHD was also evident in subsidiary analyses with only acute myocardial infarction and cardiac death as the outcome. CONCLUSION: If the observed associations were causal then workplace interventions should focus on concrete managerial behaviours in order to prevent IHD in employees.

Job strain and ischaemic disease: does the inclusion of older employees in the cohort dilute the association? The WOLF Stockholm Study.

OBJECTIVE: Evidence on the association between job strain and ischaemic disease is mixed. This study examined whether including older age individuals in a cohort used to assess job strain attenuates findings towards the null. DESIGN: A prospective cohort study with baseline screening in 1992-5. A follow-up for ischaemic disease until 2003 was based on linkages to national registries. Ischaemic disease was corroborated by objective criteria (hospitalisation as a result of acute myocardial infarction, unstable angina or ischaemic stroke; or death from ischaemic heart disease, cardiac arrest or ischaemic stroke). PARTICIPANTS: 3160 male employees aged 19-65 years without pre-existing or current ischaemic disease. RESULTS: 93 cases of incident ischaemic disease were recorded. In the 19-55 year age group, the participants with job strain had a 1.76 (95% CI 1.05 to 2.95) times higher age-adjusted risk of incident ischaemic disease than those free of strain. Further adjustment for conventional cardiovascular risk factors had little effect on this association, but the impact of job strain was reduced by 70% to non-significant after the inclusion of employees older than 55 years in the cohort (hazard ratio 1.22, 95% CI 0.75 to 1.96). CONCLUSIONS: Including older employees in a cohort may dilute the effect of job strain on cardiovascular disease and is a potential reason for inconsistent findings in previous studies.

Psychosocial stress and atherosclerosis: family and work stress accelerate progression of coronary disease in women. The Stockholm Female Coronary Angiography Study.

OBJECTIVE: To examine the impact of psychosocial stress, experienced in the family and work life, on the progression of coronary atherosclerosis in women cardiac patients. DESIGN: Longitudinal follow-up study. The mean luminal diameter change over 3 years was averaged over 10 predefined coronary segments, representing the entire coronary tree. Stress in family life was measured by using the Stockholm Marital Stress Scale and that of work life by the demand-control questionnaire. SUBJECTS: Amongst patients enrolled in the Stockholm Female Coronary Angiography Study, 80 women were evaluated for stress exposure and coronary atherosclerosis progression using serial quantitative coronary angiography. RESULTS: Multi-variable-controlled mixed models anova analyses revealed that women with high stress from either family or work had significant disease progression over 3 years, whereas those with low stress had only slight progression. In women who were free of stress from either family or work life, i.e. they were satisfied with both of these life domains, the coronary artery changes had regressed. Their mean coronary luminal diameter increased by 0.22 mm (95% CI: 0.10; 0.35 mm) when compared with women who experienced stress from both sources, whose luminal diameter decreased by 0.20 mm (95% CI: -0.14; -0.25). These associations were independent of baseline luminal diameter and standard cardiovascular risk factors, including age smoking, hypertension and HDL at baseline. CONCLUSIONS: Stress from family or work life may accelerate coronary disease processes in women, whereas relative protection may be obtained from a satisfactory job and a happy marriage.

Quality of life and maintenance of improvements after early multimodal rehabilitation: a 5-year follow-up.

PURPOSE: There is a paucity of long-term evaluations on rehabilitation of musculoskeletal disorders, e.g., neck, shoulder or back pain. The aim of this study was to assess quality of life and the effect of early multimodal rehabilitation on 91 patients with musculoskeletal pain and disability at a 5-year follow-up. METHOD: The follow-up assessment, which included questions on pain, function, quality of life, perceived health, sick leave and psychosomatic symptoms, was performed 5 years after the assessment of baseline status. RESULTS: Improvements in pain, perceived health and psychosomatic symptoms were maintained at the 5-year follow-up. In addition, improvements in function, quality of life, and level of acceptable pain were significant in comparison to baseline. At the time of the baseline assessment all patients were on sick leave (13% were on partial sick leave). At the 5-year follow-up, 58% of the patients were at work part or full time. The results show that those working differed significantly from those not working at the 5-year follow-up on almost all variables, indicating that those working enjoy better health. The most salient prognostic factors for return to work were perceived health and educational level at the time of the baseline evaluation. CONCLUSIONS: These results show that treatment improved quality of life and the effects were basically maintained at 5 years. Work capacity as reflected in return to work increased greatly (81%) at a 1-year follow-up and was substantial (58%) at the 5-year follow-up. Moreover, perceived health and educational levels were important prognostic factors. Finally, the fact that patients working reported better health underscores the probable importance of return to work. Our results imply that it may be feasible to obtain long-term benefits from such a primary care-based intervention.

Are intrinsic motivational factors of work associated with functional incapacity similarly regardless of the country?

BACKGROUND: Many psychosocial models of wellbeing at work emphasise the role of intrinsic motivational factors such as job autonomy, job complexity, and innovativeness. However, little is known about whether the employees of multinational enterprises differ from country to country with regard to intrinsic motivational factors, and whether these factors are associated with wellbeing similarly in the different countries. The purpose of this study was to examine the level of intrinsic motivational factors and their impact on functional incapacity in different countries in a multinational corporation. METHODS: In 2000, data were collected from a globally operating corporation with a questionnaire survey. The participants were 13 795 employees (response rate 59%; 56% under age 45; 80% men; 61% blue collar employees), who worked in similar industrial occupations in five countries (Canada, China, Finland, France, and Sweden). RESULTS: The Chinese employees reported higher autonomy and lower complexity at work than the employees from the other countries. After adjustment for age, sex, socioeconomic status, and physical work environment, job autonomy, and job complexity at work were associated with functional incapacity in most countries, whereas in China the impact was significantly stronger. In Finland and in China employees with low innovativeness at work were more prone to functional incapacity than corresponding employees in other countries. CONCLUSIONS: The level of intrinsic motivational factors varied between the Chinese employees and those in other countries. In line with theoretical notions, the relation between intrinsic motivational factors of work and functional incapacity followed a similar pattern in the different countries. However, these country specific results show that a culture specific approach to employee wellbeing should also be applied.

Acoustics and psychosocial environment in intensive coronary care.

BACKGROUND: Stress, strain, and fatigue at the workplace have previously not been studied in relation to acoustic conditions. AIMS: To examine the influence of different acoustic conditions on the work environment and the staff in a coronary critical care unit (CCU). METHOD: Psychosocial work environment data from start and end of each individual shift were obtained from three shifts (morning, afternoon, and night) for a one-week baseline period and for two four-week periods during which either sound reflecting or sound absorbing tiles were installed. RESULTS: Reverberation times and speech intelligibility improved during the study period when the ceiling tiles were changed from sound reflecting tiles to sound absorbing ones of identical appearance. Improved acoustics positively affected the work environment; the afternoon shift staff experienced significantly lower work demands and reported less pressure and strain. CONCLUSIONS: Important gains in the psychosocial work environment of healthcare can be achieved by improving room acoustics. The study points to the importance of further research on possible effects of acoustics in healthcare on staff turnover, quality of patient care, and medical errors.

Mental fatigue, work and sleep.

OBJECTIVE: The study examined the multivariate relationship between mental fatigue and different work-related (work load, work hours) and background/life style factors, as well as disturbed sleep. METHODS: A total of 5720 healthy employed men and women living in the greater Stockholm area participated in a questionnaire study on cardiovascular risk factors. The data were analysed using a multiple logistic regression analysis with self-rated fatigue as the dependent variable. RESULTS: Fatigue was predicted by disturbed sleep (4.31; 3.50-5.45, high immersion in work (4.17; 2.93-5.94), high work demands (2.39; 1.54-3.69), social support, being a female, being a supervisor and high age. Shift work, work hours (including overtime) and influence at work did not become significant predictors. With control for work demands a high number of work hours was associated with lower fatigue. CONCLUSION: Disturbed sleep is an important predictor of fatigue, apparently stronger than previously well-established predictors such as work load, female gender, lack of exercise, etc.

Low job control and myocardial infarction risk in the occupational categories of Kaunas men, Lithuania.

STUDY OBJECTIVE: To determine the association between adverse psychosocial characteristics at work and risk of first myocardial infarction in the occupational categories of Kaunas men, Lithuania. DESIGN: The analysis was based upon a case-control study among full time working men in the general population of Kaunas. OUTCOME MEASURE: First non-fatal myocardial infarction diagnosed in 2001-2002. The Swedish version of the demand-control questionnaire was used to examine the effect of job control and demands. SETTING: Kaunas, the second largest city in Lithuania, a former socialist country in a transition market economy. PARTICIPANTS: Cases were 203 men 25-64 years of age with a first non-fatal myocardial infarction and controls were 287 men group randomly selected from the study base. MAIN RESULTS: Low job control had a significant effect on myocardial infarction risk in the general 25-64 year old Kaunas male population (OR = 2.68; 95% CI 1.68 to 4.28) after adjustment for age and socioeconomic status. Low job control was a risk factor in the occupational categories of the increased myocardial infarction risk (1st occupational category--legislators, senior officials and managers and the 8th--plant and machine operators and assemblers; OR = 2.78; 95% CI 1.31 to 5.93 and 2.72; 95% CI 1.56 to 4.89, respectively, after adjustment for age and socioeconomic status). Though the adjusted odds ratio estimates were significantly high for the rest of the occupational categories (2nd--professionals, 3rd--technicians and associate professionals, and 7th--craft and related trades workers). CONCLUSIONS: The association between low job control and first myocardial infarction risk was significant for all occupational categories of Kaunas men.