The relationship between job enrichment and abdominal obesity: a longitudinal field study of apparently healthy individuals.

Obesity has become an epidemic in modern society. However, there is a paucity of research about how job context affects obesity. To enhance our knowledge we used a large, heterogeneous sample of apparently healthy employees (n = 1,949) across two time periods with an average of close to 3.5 years between measures. We tested a hypothesized curvilinear effect of job enrichment on changes in two stress related indicators of abdominal obesity over time: waist circumference (WC) and waist-hip ratio (WHR). Job enrichment consisted of the job dimensions of variety, identity, significance, autonomy, and feedback, and in our analysis we controlled for demographics and health related behaviors, including weekly sports activity, number of cigarettes smoked per day, and weekly alcohol consumption. The results supported the hypothesized U-shaped relationship between job enrichment and changes in both indicators of abdominal obesity over time, such that the level of abdominal obesity was reduced when job enrichment was moderate and was increased when job enrichment was either high or low. As expected, no such association was observed for the general obesity measure of body mass index (BMI). We discuss the theoretical and practical implications of these results.

Burnout and vigor as predictors of the incidence of hyperlipidemia among healthy employees.

We examined the effects of burnout and vigor on the incidence of hyperlipidemia. Based on the bivariate theoretical approach to negative and positive affects and on past studies on the prediction of blood lipids by burnout and vigor, we expected increases from Time 1 (T1) to Time 2 (T2) in burnout levels to be associated with an increase in the risk for hyperlipidemia and T1-T2 increases in vigor levels to be associated with a decrease in the risk of hyperlipidemia. Our sample consisted of 3,337 healthy employees (2,214 men and 1,123 women) who were followed up for about 27 months on average. Burnout and vigor were assessed by well-validated multiple-item instruments. We used logistic regressions and controlled for variables associated with blood lipids as well as with vigor and burnout. We cross-validated all self-reported hyperlipidemia by their T2 lipids levels. As expected, we found that T1-T2 increases in vigor levels were associated with a decreased risk of hyperlipidemia. However, the T1-T2 change in burnout levels was marginally significant (p = .06) in predicting hyperlipidemia. We consider our finding that vigor and burnout are independently associated with the risk of hyperlipidemia as providing support for the bivariate approach to affective states. In addition, our major finding suggests a possible mechanism via which vigor influences physical health outcomes.

The relationship of the job demands-control-support model with vigor across time: testing for reciprocality.

We used a longitudinal design to investigate the hypotheses that the components of the Job Demands-Control-Support model and changes in their levels over time predict subsequent changes in levels of positive affect of vigor over time, and vice versa. Our study was conducted on a sample of adults working in a variety of occupations (N = 909, 68% men) at three points in time (T1, T2, and T3), over a period of about four years, controlling for neuroticism and other potential confounding variables. Job control at T1 and increase in its levels from T1 to T2 predicted an increase from T2 to T3 in the levels of vigor, whereas for social support, only its level at T1 predicted an increase from T2 to T3 in levels of vigor. An increase from T1 to T2 in levels of job demands predicted an increase from T2 to T3 in levels of vigor only for those rated low on neuroticism. Vigor at T1 predicted an increase from T2 to T3 in levels of job control and social support, but not changes from T2 to T3 in levels of job demands. The reciprocal causal relationship between job resources and vigor exists regardless of the demands of the work environment.

Work characteristics as predictors of diabetes incidence among apparently healthy employees.

The objective of this article was to investigate the associations of the Job Demand Control-Support (JDC-S) model's components, job demands, job control, and work social support, as well as their interactive terms, with the risk of Type 2 diabetes. Participants were apparently healthy 5,843 men and women who underwent routine health checks at two points of time, about 41 months apart from one another. New cases of diabetes (N = 182) during follow-up period were defined based on fasting glucose value ≥ 126 mg/dl or glycosylated hemoglobin value ≥ 6.5% or self-reported physician diagnosis of diabetes and taking medications to treat it. The measures for assessing workload (representing job demands), job control, and work social support were all based on validated scales constructed to test the JDC-S model. In testing the hypotheses, we used logistic regressions and controlled for well-established risk factors for diabetes, including sociodemographic, physiological, and behavioral risk factors. We also controlled for depressive symptoms. The hypothesis that the higher the baseline levels of work social support, the lower the risk of diabetes, was supported (Odd Ratio = .78, significant at the p < .05 level). In an exploratory analysis, workload was found to have a U-shaped relationship with diabetes risk. We did not find direct effects of job control nor of any interactive term including the JDC-S model components on diabetes risk. Work social support is a protective factor, reducing the risk of diabetes. Both underload and overload may increase the risk of diabetes.

The effects of vigour on measures of obesity across time.

OBJECTIVES: Past studies expected measures of obesity to be positively associated with positive affects. However, this hypothesis was not tested in reference to a specific positive affect. We tested the hypothesized unidirectional effects of measures of obesity on vigour, representing a positive affect, and of vigour on measures of obesity. DESIGN: We used a longitudinal design, separately for men and women. Participants were 1,876 and 931 healthy men and women, respectively, examined at Time 1 (T1) and Time 2 (T2), about 2 years apart. METHODS: Measures of obesity included body mass index, waist circumference, and waist-to-hip ratio. Vigour was assessed by the Shirom-Melamed Vigour Measure. We used structural equation modelling to test our hypotheses. RESULTS: We found that for both genders, T1 measures of obesity did not predict either T1 or T2 vigour. Among both genders, we found support for the effects of T1 vigour on T1 but not on T2 measures of obesity. CONCLUSIONS: To the extent that the 'Jolly fat hypothesis' refers to the effects of measures of obesity on positive affects, we failed to support it for vigour as a positive affect. Vigour has contemporaneous but not longitudinal effects on body weight.

The relationships between self-rated health and serum lipids across time.

BACKGROUND AND PURPOSE: We studied the hypothesized effects of changes in self-rated health (SRH) on subsequently assessed changes in the levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, and triglycerides (TRI), separately for men and women. We also investigated the reverse causation hypothesis, expecting the initial changes in the levels of serum lipids to predict subsequently assessed changes in SRH levels. METHODS: We used a longitudinal design and controlled for possible confounders known to be precursors of both SRH and the above three serum lipids. Participants were apparently healthy men (N = 846) and women (N = 378) who underwent a routine health check at three points of time (T1, T2, and T3); T1 and T3 were on the average 40 and 44 months apart for the men and women, respectively. RESULTS AND CONCLUSIONS: For the men, relative to T1 SRH, an increase in T2 SRH was associated with an increase in the T3 HDL-C levels relative to T2 HDL-C and with a decrease in the T3 TRI levels relative to T2 TRI. For the women, initial changes in the SRH levels did not predict follow-up changes in either of the lipids. For both genders, the reverse causation hypothesis, expecting the T1-T2 change in each of the serum lipids to predict T2-T3 change in SRH, was not supported. For the men, there is support for the hypothesis that the effects of SRH on morbidity and mortality, found by past meta-analytic studies, could be mediated by serum lipids.

The big five personality factors as predictors of changes across time in burnout and its facets.

We tested the effects of Neuroticism and Conscientiousness on burnout across time, controlling for age, gender, work hours, and depressive symptoms. Our theoretical model included both global burnout and its physical, emotional, and cognitive facets, consistent with the bifactor approach to modeling second-order constructs in structural equation modeling. Data were gathered from 1,105 respondents (63% men) who completed questionnaires at Time 1 (T1) and approximately 24 months later at Time 2 (T2). Neuroticism positively predicted T1 global burnout and negatively predicted T1 and T2 emotional exhaustion. Conscientiousness negatively predicted T1 global burnout and T1 and T2 cognitive weariness, and positively predicted T1 and T2 emotional exhaustion. Our gender-specific exploratory analysis revealed that for each gender, Neuroticism and Conscientiousness predicted different facets of burnout at T1 and T2. We recommend that future research test the possibility that the associations of Neuroticism and Conscientiousness with global burnout and its facets may be gender specific.

Life and Job Satisfaction as Predictors of the Incidence of Diabetes.

We studied the hypothesised effects of baseline levels of life satisfaction and of job satisfaction on the incidence of diabetes. Participants were 2,305 apparently healthy men and women who underwent routine health checks at two points in time, about 20 months apart. New cases of diabetes (N=104) were defined based on fasting glucose value > 125, or glycosylated hemoglobin value > 6.5, or self-reported physician diagnosis of diabetes and taking medications to treat it. Life satisfaction was measured using the scale constructed by Diener et al. (1985) while job satisfaction was assessed based on the Survey of Working Conditions. In the analyses, we controlled for socio-demographic predictors, for known physiological and behavioral precursors of diabetes, and for depressive symptoms. There was support for our hypothesis that the higher the baseline levels of life satisfaction, the lower the incidence of diabetes. However, job satisfaction did not predict the incidence of diabetes. We obtained the same results when limiting the analysis to new cases of diabetes based on objective criteria only and when using as predictors both life and job satisfaction. We suggest that life satisfaction could be a protective factor reducing the risk of diabetes.

The across-time associations of the five-factor model of personality with vigor and its facets using the bifactor model.

We tested hypothesized across-time associations of personality traits with the affective state of global vigor and its physical, emotional, and cognitive facets. The study was carried out in the context of work, where vigor represents a discrete, positive affective response to one's ongoing interactions with specific elements of the work environment. Our model was based on the bifactor approach to modeling second-order constructs in structural equation modeling. Data were gathered from 1,217 reportedly healthy respondents who underwent a periodical health examination at Time 1 (T1) and Time 2 (T2), about 24 months apart. We found that, independent of T1 and T2 global vigor, agreeableness and conscientiousness predicted both T1 and T2 levels of vigor's emotional facet, and openness predicted vigor's cognitive facet at both T1 and T2.

Work-based predictors of mortality: a 20-year follow-up of healthy employees.

OBJECTIVES: This study investigated the effects of the Job-Demand-Control-Support (JDC-S) model's components, workload, control, peer and supervisor social support, on the risk of all-cause mortality. Also examined was the expectation that the above work-based components interact in predicting all-cause mortality. The study's hypotheses were tested after controlling for physiological variables and health behaviors known to be risk factors for mortality. MAIN OUTCOME MEASURE: The design used was prospective. Baseline data were obtained from healthy employees (N = 820) who underwent periodic health examinations in 1988. Follow-up data on all-cause mortality were obtained from the participants' computerized medical file, kept by their HMO, in 2008. The baseline data covered socioeconomic, behavioral, and biological risk factors in addition to the components of the JDC-S model. During the period of follow-up, 53 deaths were recorded. Data were analyzed using Cox regressions. RESULTS: Only one main effect was found: the risk of mortality was significantly lower for those reporting high levels of peer social support. The study found two significant interactions. Higher levels of control reduced the risk of mortality for the men and increased it for the women. The main effect of peer social support on mortality risk was significantly higher for those whose baseline age ranged from 38 to 43 but not for the older than 43 or the younger than 38 participants. CONCLUSION: Peer social support is a protective factor, reducing the risk of mortality, while perceived control reduces the risk of mortality among men but increases it among women.

Elevated burnout predicts the onset of musculoskeletal pain among apparently healthy employees.

Musculoskeletal (MS) pain is highly prevalent in the working population, often resulting in chronic disability. Burnout represents accumulated exposure to work-related stresses and therefore could predict the incidence of MS pain. We investigated prospectively the extent to which changes in the levels of burnout over time predict new cases of MS pain. Participants were 1,704 apparently healthy employed men and women who underwent periodic health examination at three points of time (T1, T2, and T3), over a period of about three years. We used the T1 to T2 changes in the levels of burnout, depressive symptoms, and anxiety to predict the onset of new cases of MS pain between T2 and T3, while controlling for possible confounders. Logistic regression results indicated that the T1-T2 change in burnout levels was associated with a 2.09-fold increased risk of MS pain (95% confidence interval = 1.07-4.10). No support was found for the possibility of reverse causation; that is, that MS pain predicts subsequent elevations of burnout levels. It was concluded that burnout might be a risk factor in the development of MS pain in apparently healthy individuals.

Feeling vigorous and the risks of all-cause mortality, ischemic heart disease, and diabetes: a 20-year follow-up of healthy employees.

OBJECTIVE: To investigate prospectively the effects of vigor at work on the end points of mortality and the prevalence of ischemic heart disease (IHD) and diabetes. METHODS: We tested the hypothesized beneficial effects of feeling vigorous at work at baseline on the risks of all-cause mortality, IHD, and diabetes during a 20-year follow-up. Participants were healthy employees (n = 968) who underwent a routine health check at baseline. We calculated the risk of all-cause mortality, IHD, and diabetes, with days as the time scale, using the Cox proportional hazard model. In our analyses, we predicted the above end points by baseline vigor, age, gender, and educational level, adjusting for the physiological risk factors of total cholesterol, glucose, and body mass index, the behavioral risk factors of smoking, alcohol intake, and physical activity, and the psychological risk factors of depressive and anxiety symptoms. RESULTS: As hypothesized, we found that, after the above adjustments, baseline vigor decreased the risk of follow-up mortality by 26% (hazard ratio, 0.74; 95% confidence interval, 0.58-0.95) and the risk of diabetes by 17% (hazard ratio, 0.83; 95% confidence interval, 0.68-0.98). However, vigor did not have a significant effect on the risk of IHD. CONCLUSIONS: Independently of physiological, behavioral, and psychological risk factors, feeling vigorous at work protected the participants from diabetes and reduced their risk of mortality.

Burnout as a predictor of all-cause mortality among industrial employees: a 10-year prospective register-linkage study.

OBJECTIVE: Burnout, a psychological consequence of prolonged work stress, has been shown to coexist with physical and mental disorders. The aim of this study was to investigate whether burnout is related to all-cause mortality among employees. METHODS: In 1996, of 15,466 Finnish forest industry employees, 9705 participated in the 'Still Working' study and 8371 were subsequently identified from the National Population Register. Those who had been treated in a hospital for the most common causes of death prior to the assessment of burnout were excluded on the basis of the Hospital Discharge Register, resulting in a final study population of 7396 people. Burnout was measured using the Maslach Burnout Inventory-General Survey. Dates of death from 1996 to 2006 were extracted from the National Mortality Register. Mortality was predicted with Cox hazard regression models, controlling for baseline sociodemographic factors and register-based health status according to entitled medical reimbursement and prescribed medication for mental health problems, cardiac risk factors, and pain problems. RESULTS: During the 10-year 10-month follow-up, a total of 199 employees had died. The risk of mortality per one-unit increase in burnout was 35% higher (95% CI 1.07-1.71) for total score and 26% higher (0.99-1.60) for exhaustion, 29% higher for cynicism (1.03-1.62), and 22% higher for diminished professional efficacy (0.96-1.55) in participants who had been under 45 at baseline. After adjustments, only the associations regarding burnout and exhaustion were statistically significant. Burnout was not related to mortality among the older employees. CONCLUSION: Burnout, especially work-related exhaustion, may be a risk for overall survival.

Aroused versus calm positive affects as predictors of lipids.

OBJECTIVE: The authors hypothesized that high-pleasure low-arousal (HPLA) would predict a subsequent decrease of low-density lipoprotein cholesterol (LDL-C) and triglycerides (TRI), as well as a subsequent increase of high-density lipoprotein cholesterol (HDL-C). The authors also hypothesized that high-pleasure high-arousal (HPHA) would have the opposite effects on these blood lipids, predicting a subsequent increase of LDL-C and TRI, and a decrease of HDL-C. DESIGN: Participants were 990 male and 595 female apparently healthy employees who underwent a routine periodic health examination at two points in time, Time 1 (T1) and Time 2 (T2), about 24 months apart. Data were analyzed separately for the men and women, and the authors controlled for possible confounders shown in past research to be implicated with hyperlipidemia. MAIN OUTCOME MEASURES: HPHA and HPLA were assessed based on the Job-Related Affective Well-Being Scale, while LDL-C, TRI, and HDL-C were assessed based on fasting blood samples. RESULTS: For the men, support for our hypotheses was found relative to HDL-C and TRI. The authors did not find support for our hypotheses for thee women. CONCLUSION: Our findings suggest that for men, the two types of positive affects may have opposite physiological consequences with respect to subsequent changes in blood lipid levels.

Workload, control, and social support effects on serum lipids: a longitudinal study among apparently healthy employed adults.

The authors investigated the direct and interactive effects of the job demand- control-support (JDC-S) model's components on subsequent changes in high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides (TRI) separately for male and female employees. In contrast to all 14 past studies on these relationships, the authors used a longitudinal design. Study participants (N = 1,137, 66% men) were all apparently healthy employees who underwent a routine health check at 2 points in time (Time 1 and Time 2) about 22 months apart. In these analyses, the authors controlled for the Time 1 level of each criterion and for other confounders. Most of the direct and moderating effects found did not support the predictions of the JDC-S model; this finding is in agreement with the majority of past cross-sectional studies. The authors did not find any evidence supporting the existence of a reverse causation for either of the components of the JDC-S model. The authors suggest that serum lipids may not be a physiological mechanism mediating the effects of the JDC-S model on atherosclerotic diseases.

Acerca de la validez del constructo, predictores y consecuencias del Burnout en el lugar de trabajo / On the construct validity, predictors and consecuences of Burnout at work

Dada la complejidad del constructo del burnout y la controversia respecto a su definición operacional (Maslach et al. 2001), se hace esencial realizar un análisis conceptual para comprender el fenómeno del burnout y las relaciones entre éste y los constructos de la depresión y la fatiga crónica que se traslapan parcialmente. Esta reseña propone entonces revisar la investigación sobre los modelos de estrés y burnout y sobre los rasgos de la personalidad que predisponen a los empleados a sentir el burnout. Después se reseñan las consecuencias del burnout proporcionando un resumen de su influencia sobre las conductas de salud del empleado, salud autocalificada y desempeño laboral respectivamente. Después de esta sección, analizo la posibilidad que los predictores a nivel organizacional influyan en los niveles de burnout de cada empleado. Finalmente, daré recomendaciones para futuras investigaciones.

Given the complexity of the construct of burnout and the controversy over its operational definition (Maslach et al. 2001), a conceptual analysis is essential for understanding the phenomenon of burnout and the relationships between burnout and the partially overlapping constructs of depression and chronic fatigue. This review then moves to review research on models of stress and burnout and on personality traits that predispose employees to feel burnout. Then, the review outlines the consequences of burnout providing a summary of the influence of burnout on employee health behaviors, self-rated health, and job performance, respectively. Following this section, I discuss the possibility that organizational-level predictors influence individual employee levels of burnout. Finally, I shall provide recommendation for future research.

Relation of educational level to inflammation-sensitive biomarker level.

It is a well-established finding that cardiovascular morbidity varies among groups of different socioeconomic status. Inflammatory processes have been proposed as a possible mediator of this variance. Level of education is an important indicator of socioeconomic status, inversely related to levels of inflammatory biomarkers. Whether this association was significant in a subpopulation of highly educated individuals was questioned. This cross-sectional study enrolled attendees of an executive health screening program intended specifically for executive and high-wage personnel from September 2002 to November 2007. A detailed questionnaire, anthropometric measurements, and laboratory data were used to determine self-reported years of education and cardiovascular risk factors. Linear regression models included high-sensitivity C-reactive protein, fibrinogen, erythrocyte sedimentation rate, and white blood cell count as dependent variables and were adjusted for multiple potential confounders. Data for 8,998 subjects (5,757 men, 3,241 women) with a mean age of 44 years (range 18 to 84) were analyzed. More than two-thirds reported >or=14 years of schooling, and >2,900 reported >or=17 years of schooling. We found a statistically significant inverse association between number of school years and high-sensitivity C-reactive protein, fibrinogen, and erythrocyte sedimentation rate. Higher levels of education were associated with lower prevalences of diabetes and current smoking in both genders and lower prevalences of hypertension and dyslipidemia in women. In conclusion, level of education was inversely associated with inflammatory biomarkers and prevalence of cardiovascular risk factors, even within highly educated populations.

The effects of physical fitness and feeling vigorous on self-rated health.

OBJECTIVE: We prospectively studied the hypothesized beneficial effects of feeling vigorous and of objective physical fitness (gauged based on functional capacity) on subsequently assessed self-rated health (SRH), controlling for possible confounders known to be precursors of SRH and of our predictors. We also investigated the reverse-causation hypothesis that SRH predicts subsequent vigor and functional capacity. DESIGN: Participants were apparently healthy employees (N = 779) who underwent a routine health check at two points of time, Time 1 (T1) and Time 2 (T2), about 18 months apart. We used regression analysis, predicting T2 SRH by T1 SRH, the control variables, and T1vigor and functional capacity. MAIN OUTCOME MEASURES: Vigor was assessed using the Shirom-Melamed Vigor Measure; objective physical fitness was indicated by functional capacity following a treadmill exercise, and self-rated health was measured by a single item. RESULTS: As hypothesized, we found that the change in T2 SRH was positively predicted by T1 vigor, functional capacity, and their interactive term. Testing the reverse causation paths, we found that T1 SRH did not predict subsequent functional capacity and was a relatively weak predictor of subsequent vigor. CONCLUSION: The affective state of vigor and objectively assessed functional capacity interact to predict subsequent changes in self-rated health.

On the nature of burnout-insomnia relationships: a prospective study of employed adults.

OBJECTIVE: This prospective study was designed to test the hypothesis that burnout and insomnia predict each other's incidence and intensification across time. Burnout is conceptualized as representing individuals' unique affective response to their exposure to chronic stressors. METHOD: Apparently healthy respondents (1356) completed questionnaires during periodic health examinations undergone at two time points T(1) and T(2), about 18 months apart. Burnout was assessed by the Shirom-Melamed Burnout Measure, while insomnia was assessed by the Brief Athens Insomnia Scale. Depressive symptomatology, neuroticism, body mass index, age, gender, follow-up duration, and T(1) levels of the criterion were controlled. RESULTS: Burnout and insomnia were found to be only moderately associated at T(1). However, logistic regression results indicated that burnout significantly predicted the development of new cases of insomnia at 18-month follow-up [odds ratio (OR)=1.93; 95% confidence interval (95% CI)=1.45-2.58], even after adjusting for depression and other potent confounders. Likewise, insomnia significantly predicted the onset of new cases of burnout at 18-month follow-up (OR=1.64; 95% CI=1.30-2.08). Hierarchical regression results indicted that T(1) burnout significantly predicted an increase in T(2) insomnia (beta=.05, P<.05), and that T(1) insomnia significantly predicted an increase in T(2) burnout (beta=.07, P<.05). DISCUSSION: The results indicate that burnout and insomnia recursively predict each other's development and intensification over time, thus suggesting that either might be a risk factor for the other across time. Possible mechanisms of link between burnout and insomnia, as well as the clinical implications of the findings, were suggested.

Inflammation markers in individuals with history of mental health crisis.

The association between temporary emotional states and systemic inflammation has never been studied. We measured the levels of systemic inflammation markers in the peripheral blood of individuals with history of mental health crisis. Erythrocyte sedimentation rate (ESR), fibrinogen plasma level, high-sensitivity C-reactive protein (hs-CRP) serum level, and white blood cell count (WBCC) were measured for each individual during routine screening examinations. History of mental health crisis was self-reported. Individuals taking psychotropic agents were excluded. A total of 4,669 males and 2,576 females were included. One hundred forty-eight (2.0%) individuals (77 males and 71 females) reported a history of mental health crisis, and 7,097 (98.0%) individuals (4,592 males and 2,505 females) did not report a history of mental health crisis. After adjustment for multiple confounders which had been associated with elevated systemic inflammation markers, the levels of systemic inflammation markers were significantly higher among males with history of mental health crisis compared with males with no history of mental health crisis, including fibrinogen plasma levels (294+/-6.1 vs. 279+/-1.9 mg/dl, p=0.010), and WBCC (7.2+/-0.2 vs. 6.8+/-0.1 x 10(3) cells/dl, p=0.039). The levels of systemic inflammation markers were not significantly higher among females with history of mental health crisis compared with females with no history of mental health crisis. History of mental health crisis might be associated with systemic inflammation in males. This finding may be relevant to the pathophysiology of cardiovascular disease in males.