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.