The association of cortisol levels with leukocyte distribution is disrupted in the metabolic syndrome

Background Leukocyte glucocorticoid sensitivity (GCS) pertains to the responsivity of leukocytes to the regulating actions of glucocorticoids, such as cortisol. Impaired endocrine regulation may link the metabolic syndrome (MetS) to the development of cardiovascular disease. We tested if the physiological association between endogenous cortisol levels and peripheral leukocyte composition becomes disrupted in individuals with MetS. Methods MetS was assessed among 689 German industrial employees. The covariance between cortisol levels and hematologic parameters (i.e., proportions of neutrophils and lymphocytes) and their ratio was explored, which has been proposed as a proxy for GCS in vivo. Cortisol level before blood collection was assessed by repeated saliva collection, and the area under the curve was calculated. Linear regression models were adjusted for potential confounders including age, gender, BMI, income, and lifestyle factors. Results Cortisol levels did not differ between subgroups. Participants without MetS (n = 552) showed the expected association of cortisol with hematologic parameters (β = 0.207 to 0.216; p values 0.10) was found among those with MetS (n = 137), consistent with a reduced GCS. Analyses of separate MetS components showed that reduced GCS was associated specifically with decreased high-density lipoprotein and elevated fasting plasma glucose. Conclusions Utilizing a novel statistical approach to infer GCS, this study provided first epidemiological evidence of aberrant physiological regulation of leukocyte distribution by endogenous cortisol levels among individuals with MetS. These findings underline the idea that MetS may involve disruption of endocrine-immune regulation

Effort-reward imbalance is associated with the metabolic syndrome — Findings from the Mannheim Industrial Cohort Study (MICS)

Background/objectives: Job stress is a predictor of cardiovascular disease incidence and mortality and the metabolic syndrome (MetS) represents one of the key pathways potentially underlying those associations. Effort-reward imbalance (ERI) represents one of the most influential theoretical work stress models, but evidence on its relationship with MetS remains sparse and with only limited generalizability. We therefore aimed to determine this association in a large occupational sample with different occupational groups. Methods: The present study used cross-sectional data from an industrial sample in Germany (n = 4141). ERI was assessed by a validated 10-item questionnaire. MetS was defined according to a joined interim statement of six expert associations involved with MetS, stating that three out of five risk factors (raised blood pressure, elevated triglycerides, low high density lipoprotein, raised fasting glucose and central obesity) qualify a patient for MetS. Multivariable associations of ERI, and its subcomponents "effort" and "reward", with MetS were estimated by logistic regression-based multivariate odds ratios (ORs) with 95% confidence intervals (CIs). Results: ERI (continuous z-score) was positively associated with MetS (zERI: OR = 1.14, 95% CI = 1.03-1.26). The association was more prominent in males (zERI: OR 1.20, 95% CI = 1.07-1.33) and in younger employees (age 18-49 zERI: OR = 1.24, 95% CI = 1.09-1.40). Analysis of the ERI subcomponents yielded weak associations of both effort (zEffort: OR = 1.12, 95% CI = 1.00-1.25) and reward (zReward: OR = 0.92, 95% CI = 0.84-1.00) with MetS. Conclusions: ERI is associated with increased occurrence of MetS, in particular among younger men. Further longitudinal studies are needed to determine the temporal relation of these associations

Three job stress models and their relationship with musculoskeletal pain in blue- and white-collar workers

Objectives: Musculoskeletal pain has been found to co-occur with psychosocial job stress. However, different conceptualizations of job stress exist, each emphasizing different aspects of the work environment, and it is unknown which of these aspects show the strongest associations with musculoskeletal pain. Further, these associations may differ for white-collar vs. blue-collar job types, but this has not been tested. The present study examined the independent and combined contributions of Effort-RewardImbalance (ERI), Job-Demand-Control (JDC) and Organizational Justice (OJ) to musculoskeletal pain symptoms among white- and blue-collar workers. Methods: Participants of a cross-sectional study (n = 1634) completed validated questionnaires measuring ERI, JDC, and OJ, and reported the frequency of pain during the previous year at four anatomical locations (lower back, neck or shoulder, arms and hands, and knees/feet). Pain reports were summarized into a single musculoskeletal symptom score (MSS). Analyses were stratified for white- and blue-collar workers. Results: Among white-collar workers, ERI and OJ were independently associated with MSS. In addition to these additive effects, significant 2-way and 3-way interactions indicated a synergistic effect of job stressors in relation to reported pain. In blue-collar workers, ERI and JDC independently associated with MSS, and a significant 3-way interaction was observed showing that the combination of job stressors exceeded an additive effect. Conclusion: ERI influences pain symptoms in both occupational groups. OJ was independent significant predictor only among white-collar workers, whereas JDC had additive predictive utility exclusively among blue-collar workers. Simultaneous exposure to multiple job stress factors appeared to synergize pain symptom reporting

Psychometric properties and differential explanation of a short measure of effort-reward imbalance at work: A study of industrial workers in Germany

Background: We test the psychometric properties of a short version of the Effort-Reward Imbalance (ERI) questionnaire in addition to testing an interaction term of this model's main components on health functioning. Methods: A self-administered survey was conducted in a sample of 2,738 industrial workers (77% men with mean age 41.6 years) from a large manufacturing company in Southern Germany. The internal consistency reliability, structural validity, and criterion validity were analyzed. Results: Satisfactory internal consistencies of the three scales: "Effort", "reward", and "overcommitment", were obtained (Cronbach's alpha coefficients 0.77, 0.82, and 0.83, respectively). Confirmatory factor analysis showed a good model fit of the data with the theoretical structure (AGFI = 0.94, RMSEA = 0.060). Evidence of criterion validity was demonstrated. Importantly, a significant synergistic interaction effect of ERI and overcommitment on poor mental health functioning was observed (odds ratio 6.74 (95% CI 5.32-8.52); synergy index 1.78 (95% CI 1.25-2.55)). Conclusions: This short version of the ERI questionnaire is a reliable and valid tool for epidemiological research on occupational health. Am. J. Ind. Med. 55:808-815, 2012. © 2012 Wiley Periodicals, Inc