Mia Söderberg

A longitudinal general population-based study of job strain and risk for coronary heart disease and stroke in Swedish men

Objectives The aim was to investigate whether psychosocial stress based on the job-demand-control (JDC) model increased the risk for coronary heart disease (CHD) and stroke. Setting Swedish men. Participants The Primary Prevention Study (PPS) comprises 6070 men born between 1915 and 1925 free from previous history of CHD and stroke at baseline (1974–1977). Psychosocial workplace exposure was assessed using a job-exposure matrix (JEM) for the JDC model based on occupation at baseline. The participants were followed from baseline examination, until death, until hospital discharge or until 75 years of age, whichever occurred first, using the Swedish national register on cause of death and the Swedish hospital discharge register for non-fatal and fatal stroke and CHD events. Cox regression models were used with stroke or CHD as the outcome, using JDC model and age as explanatory variables, as well as stratified models with regard to smoking, self-reported stress, socioeconomic status, obesity, hypertension and diabetes. Primary and secondary outcome measures Risk for stroke and CHD. Results There was an increased risk (HR) for CHD in relation to high strain (HR 1.31, 95% CI 1.01 to 1.70). The risk was further increased among ever-smokers and among blue-collar workers. There was a relation between low control and increased risk for CHD (HR 1.19, 95% CI 1.06 to 1.35). There was no increased risk for stroke in any of the JDC categories. Conclusions Exposure to occupational psychosocial stress defined as job strain or low control increased the risk for CHD, especially among smokers and blue-collar workers. There was no increased risk for stroke in any of the JDC categories.

A cross-sectional study of the relationship between job demand-control, effort-reward imbalance and cardiovascular heart disease risk factors

BackgroundThis cross-sectional study explored relationships between psychosocial work environment, captured by job demand-control (JDC) and effort-reward imbalance (ERI), and seven cardiovascular heart disease (CHD) risk factors in a general population.MethodThe sampled consists of randomly-selected men and women from Gothenburg, Sweden and the city’s surrounding metropolitan areas. Associations between psychosocial variables and biomarkers were analysed with multiple linear regression adjusted for age, smoking, education and occupational status.ResultsThe study included 638 men and 668 women aged 24–71. Analysis between JDC and CHD risk factors illustrated that, for men, JDC was associated with impaired scores in several biomarkers, especially among those in high strain jobs. For women, there were no relationships between JDC and biomarkers. In the analysis of links between ERI and CHD risk factors, most associations tested null. The only findings were raised triglycerides and BMI among men in the fourth quartile of the ERI-ratio distribution, and lowered LDL-cholesterol for women. An complementary ERI analysis, combining high/low effort and reward into categories, illustrated lowered triglycerides and elevated HDL-cholesterol values among women reporting high efforts and high rewards, compared to women experiencing low effort and high reward.ConclusionsThere were some associations between psychosocial stressors and CHD risk factors. The cross-sectional design did not allow conclusions about causality but some results indicated gender differences regarding sensitivity to work stressors and also how the models might capture different psychosocial dimensions.

The association between job strain and atrial fibrillation in Swedish men

Objectives The purpose of this study was to investigate whether psychosocial stress defined as high strain based on the job demand–control model increases risk for atrial fibrillation. Methods The present study comprised 6035 men born between 1915 and 1925 and free from previous coronary heart disease, atrial fibrillation and stroke at baseline (1974–1977). Work-related psychosocial stress was measured using a job-exposure matrix for the job demand–control model based on occupation at baseline. The participants were followed from baseline examination until death, hospital discharge or 75 years of age, using the Swedish national register on cause of death and the Swedish hospital discharge register for any registration for atrial fibrillation, resulting in the identification of 436 cases. Data were analysed with Cox regression models with atrial fibrillation as the outcome using high strain as the explanatory variable adjusted for age, smoking, body mass index, hypertension, diabetes and socioeconomic status. Results There was an increased risk for atrial fibrillation in relation to high strain (HR 1.32, 95% CI 1.003 to 1.75). When the four categories of the job-strain model were included and low strain was used as reference, the risk for high strain decreased (HR 1.23, 95% CI 0.84 to 1.82). Conclusions Exposure to occupational psychosocial stress defined as high strain may be associated with increased risk for atrial fibrillation. The observed increase in risk is small and residual confounding may also be present.

Mental disorders and stress resilience in adolescence and long-term risk of early heart failure among Swedish men

BACKGROUND Recent research suggests that the prevalence of early heart failure may be on the rise. Compromised mental health in adolescence may help to explain this phenomenon. We aimed to investigate whether nonpsychotic mental disorder and low stress resilience in late adolescence were associated with increased risk of early heart failure. METHODS A prospective cohort study of 18-year-old men (n=1,784,450) who enlisted 1968-2005. At the conscription examination, 74,522 individuals were diagnosed with nonpsychotic mental disorders. Stress resilience was rated by psychologists; values were trichotomized. The risk of heart failure during the 46-year follow-up was calculated with Cox proportional hazards models. Baseline comorbidities, BMI, blood pressure, fitness, IQ, and parental education were included in the models. RESULTS Incident cases of heart failure (n=9962) were identified in the National Hospital Register. In fully adjusted models, increased risk of early heart failure was observed in males diagnosed with nonpsychotic mental disorders at conscription (hazard ratio (HR), 1.36; 95% confidence interval (CI), 1.25-1.47). The highest risk was seen among men with the risk factor alcohol/substance use (HR 1.90; 95% CI 1.59-2.28). Conscripts with the risk factor low stress resilience showed increased risk of heart failure compared to those with high scores (HR 1.41; 95% CI 1.30-1.53). CONCLUSION Nonpsychotic mental disorder, as well as low stress resilience in late adolescence may be associated with increased risk of early heart failure. Adolescence is potentially an important time for mental health interventions that may reduce both short and long-term consequences.

Future marginalisation and mortality in young Swedish men with non-psychotic psychiatric disorders and the resilience effect of cognitive ability: a prospective, population-based study

Objective Large-scale studies examining future trajectories of marginalisation and health in adolescents with mental illness are scarce. The aim of this study was to examine if non-psychotic psychiatric disorders (NPDs) were associated with future indicators of marginalisation and mortality. We also aimed to determine whether these associations might be mediated by education level and attenuated by high cognitive ability. Design This is a prospective cohort study with baseline data from the Swedish Conscription register. Setting The study was carried out in Sweden from 1969 to 2005. Participants All of the participants were 18-year-old men at mandatory conscription in Sweden between 1969 and 2005 (n=1 609 690). Measures NPDs were clinically diagnosed at conscription. Cognitive ability was measured by a standardised IQ test at conscription. National register data covered information on welfare support, long-term unemployment, disability pension (DP) and mortality over a period of 1–36 years. Results NPD at the age of 18 years was a predictor of future welfare support, OR 3.73 (95% CI 3.65 to 3.80); long-term unemployment, OR 1.97 (95% CI 1.94 to 2.01); DP, HR 2.95 (95% CI 2.89 to 3.02); and mortality, HR 2.45 (2.33–2.52). The adjusted models suggested that these associations were not confounded by fathers’ educational level, cognitive ability had only a minor attenuating effect on most associations and the mediating effect of own educational level was small. Conclusions The present study underlines a higher prevalence of future adversities in young men experiencing NPDs at the age of 18 years. It also indicates that higher cognitive ability may work as a potential resilience factor against future marginalisation and mortality.

Psychosocial Work Environment and Risk of Ischemic Stroke and Coronary Heart Disease: A Prospective Longitudinal Study of 75 236 Construction Workers

OBJECTIVES The present study aimed to investigate whether different dimensions of psychosocial stress, as measured by the job demand-control model (JDC), were associated with increased risks of ischemic stroke and coronary heart disease (CHD). METHODS A cohort of 75 236 male construction workers was followed from 1989-2004. Exposure to psychosocial stress was determined by a questionnaire answered in 1989-1993. Events of ischemic stroke and CHD were found by linkage to the Swedish Causes of Death and National Patient registers. Hazard ratios (HR) were obtained from Cox regression models, adjusted for age, smoking habits, body mass index and systolic blood pressure. RESULTS There were 1884 cases of CHD and 739 cases of ischemic stroke. Regarding ischemic stroke, no association was found between job demands [HR 1.12, 95% confidence interval (95% CI) 0.89-1.40, highest versus lowest quintile] or job control (HR 1.04, 95% CI 0.82-1.32, lowest versus highest quintile). Regarding CHD, job demands were associated to CHD (HR 1.18, 95% CI 1.02-1.37, highest vs. lowest quintile), but no consistent trend was seen among quintiles. The results were inconsistent in relation to job control. The division of JDC into four categories showed no significant associations with either ischemic stroke or CHD. CONCLUSIONS This exploratory study showed no significant associations between psychosocial work environment and ischemic stroke, and the associations between job demands and control and CHD were inconsistent and weak. The combination of job control and job demand showed no significant associations with either ischemic stroke or CHD.

Longitudinal study of occupational noise exposure and joint effects with job strain and risk for coronary heart disease and stroke in Swedish men

Objectives The aims were to investigate whether occupational noise increased the risk for coronary heart disease (CHD) and stroke and to elucidate interactions with stressful working conditions in a cohort of Swedish men. Design This is a prospective cohort study on CHD and stroke in Swedish men followed until death, hospital discharge or until 75 years of age, using Swedish national registers on cause of death and hospital discharges. Baseline data on occupation from 1974 to 1977 were used for classification of levels of occupational noise and job demand-control. Cox regression was used to analyse HRs for CHD and stroke. Setting Swedish men born in 1915–1925. Primary and secondary outcome measures CHD and stroke. Participants The participants of the study were men from the Primary Prevention Study, a random sample of 10 000 men born in 1915–1925 in Gothenburg. Subjects with CHD or stroke at baseline or were not employed were excluded. The remaining subjects with complete baseline data on occupation, weight, height, hypertension, diabetes, serum cholesterol and smoking constituted the study sample (5753 men). Results There was an increased risk for CHD in relation to noise levels 75–85 dB(A) and >85 dB(A) compared with <75 dB(A) (HR 1.15, 95% CI 1.01 to 1.31, and HR 1.27, 95% CI 0.99 to 1.63, respectively). Exposure to noise peaks also increased the risk for CHD (HR 1.19, 95% CI 1.03 to 1.38). Among those with high strain (high demands and low control) combined with noise >75 dB(A), the risk for CHD further increased (HR 1.80, 95% CI 1.19 to 2.73). There was no significantly increased risk for stroke in any noise category. Conclusions Exposure to occupational noise was associated with an increased risk for CHD and the risk further increased among those with concomitant exposure to high strain. None of the analysed variables were related to increased risk for stroke.

Impact of changes in welfare legislation on the incidence of disability pension. A cohort study of construction workers.

Aims: Study objectives were to investigate how changes in social insurance legislation influenced the incidence of disability pension. Methods: The study included 295,636 male construction workers who attended health examinations between 1971 and 1993, aged 20–60 years and without previous disability pension. Via the Swedish National Insurance Agency national register we identified 66,046 subjects who were granted disability pension up until 2010. The incidence rates were calculated and stratified according to age and diagnosis. Results: The incidence rate of disability pension was fairly stable until the 1990s when large variations occurred, followed by a strong decreasing trend from the early 2000s to 2010. Trends in incidence rates, stratified by age and diagnosis, showed a consistent decrease in cardiovascular disease for all age groups. In subjects aged 30–49 years there was a high peak around 2003 for musculoskeletal diseases and psychiatric diseases. For the age group 50–59 years, musculoskeletal diagnosis, the most common cause of disability pension, had a sharp peak around 1993 and then a decreasing trend. In the 60–64 age group, the incidence rate for psychiatric diagnosis was stable, while incidence rates for musculoskeletal diagnosis varied during the 1990s. Conclusions: There are considerable variations in the incidence rate of disability pension over time, with different patterns depending on age and diagnosis. Changes in social insurance legislation, as well as in administration processes, seem to influence the variation.

Cardiovascular fitness in late adolescent males and later risk of serious non-affective mental disorders: a prospective, population-based study

BACKGROUND Cardiovascular fitness in late adolescence is associated with future risk of depression. Relationships with other mental disorders need elucidation. This study investigated whether fitness in late adolescence is associated with future risk of serious non-affective mental disorders. Further, we examined how having an affected brother might impact the relationship. METHOD Prospective, population-based cohort study of 1 109 786 Swedish male conscripts with no history of mental illness, who underwent conscription examinations at age 18 between 1968 and 2005. Cardiovascular fitness was objectively measured at conscription using a bicycle ergometer test. During the follow-up (3-42 years), incident cases of serious non-affective mental disorders (schizophrenia and schizophrenia-like disorders, other psychotic disorders and neurotic, stress-related and somatoform disorders) were identified through the Swedish National Hospital Discharge Register. Cox proportional hazards models were used to assess the influence of cardiovascular fitness at conscription and risk of serious non-affective mental disorders later in life. RESULTS Low fitness was associated with increased risk for schizophrenia and schizophrenia-like disorders [hazard ratio (HR) 1.44, 95% confidence interval (CI) 1.29-1.61], other psychotic disorders (HR 1.41, 95% CI 1.27-1.56), and neurotic or stress-related and somatoform disorders (HR 1.45, 95% CI 1.37-1.54). Relationships persisted in models that included illness in brothers. CONCLUSIONS Lower fitness in late adolescent males is associated with increased risk of serious non-affective mental disorders in adulthood.

Cause-specific mortality in Swedish males diagnosed with non-psychotic mental disorders in late adolescence: a prospective population-based study

Background While risk of premature death is most pronounced among persons with severe mental illness, also milder conditions are associated with increased all-cause mortality. We examined non-psychotic mental (NPM) disorders and specific causes of natural death in a cohort of late adolescent men followed for up to 46 years. Methods Prospective cohort study of Swedish males (n=1 784 626) who took part in structured conscription interviews 1968–2005. 74 525 men were diagnosed with NPM disorders at or prior to conscription. Median follow-up time was 26 years. HRs for cause-specific mortality were calculated using Cox proportional hazards models. Results Risks in fully adjusted models were particularly elevated for death by infectious diseases (depressive and neurotic/adjustment disorders (HR 2.07; 95% CI 1.60 to 2.67), personality disorders (HR 2.90; 95% CI 1.96 to 4.28) and alcohol-related and other substance use disorders (HR 9.02; 95% CI 6.63 to 12.27)) as well as by gastrointestinal causes (depressive and neurotic/adjustment disorders (HR 1.64; 95% CI 1.42 to 1.89), personality disorders (HR 2.77; 95% CI 2.27 to 3.38) and alcohol-related/substance use disorders (HR 4.41; 95% CI 3.59 to 5.42)). Conclusion Young men diagnosed with NPM disorders had a long-term increased mortality risk, in particular due to infectious and gastrointestinal conditions. These findings highlight the importance of early preventive actions for adolescents with mental illness.