High-Frequency Heart Rate Variability Is Prospectively Associated With Sleep Complaints in a Healthy Working Cohort.

OBJECTIVE: Vagus nerve functioning, as indexed by high-frequency heart rate variability (HF-HRV), has been implicated in a wide range of mental and physical health conditions, including sleep complaints. This study aimed to test associations between HF-HRV measured during sleep (sleep HF-HRV) and subjective sleep complaints 4 years later. METHODS: One hundred forty-three healthy employees (91% male; MAge = 47.8 years [time 2], SD = 8.3 years) of an industrial company in Southern Germany completed the Jenkins Sleep Problems Scale, participated in a voluntary health assessment, and were given a 24-hour ambulatory heart rate recording device in 2007. Employees returned for a health assessment and completed the Jenkins Sleep Problems Scale 4 years later. RESULTS: Hierarchical regression analyses showed that lower sleep HF-HRV measured in 2007 was associated with higher self-reported sleep complaints 4 years later after controlling for covariates (rab,c = -0.096, b = -0.108, 95% CI, -0.298 to 0.081, ΔR2 = 0.009, p = .050). CONCLUSIONS: These data are the first to show that lower sleep HF-HRV predicted worse sleep 4 years later, highlighting the importance of vagus nerve functioning in adaptability and health.

Stress at work is associated with intima media thickness in older male employees, independent of other sources of stress perception.

Chronic stress at work shows a moderate but robust longitudinal association with cardiovascular disease (CVD). Atherosclerosis is a pathophysiological process of most CVD, for which intima media thickness (IMT) of the carotid artery is used as an early marker. Its relationship with stress at work has remained largely unexplored, and the present study therefore aimed to elucidate the association between stress at work, assessed as effort-reward imbalance (ERI), and IMT. This cross-sectional study comprised of 501 male German employees aged 42 (19-64) years at enrollment into the Mannheim Industrial Cohort Study. Clinical assessments used fasting blood samples and IMT measurement. Self-report questionnaires assessed sources of perceived stress. Analyses adjusted for medical history, life style, and socio-economic status (SES) indicators as well as general perceived stress and worries to determine the specificity of ERI. Linear regression models estimated the association of ERI with IMT, stratifying for age groups and adjusting for potential confounders. ERI ratio increased until the age of 50 years and abated thereafter. In participants younger than 50 years IMT measurements were not associated with ERI ratios. However, despite lower mean ERI ratios in participants older than 50 years, this age group showed a significant relationship with IMT (standardized Beta = .36, p < .01), adjusting for multiple confounders including general perceived stress and worries. These analyses suggest that atherosclerosis in older employees is specifically related to stress at work. Longitudinal studies will help to elucidate the temporal relationship between stress exposure and downstream biological mechanisms.Lay summaryOur study explored the association of job stress and the calcification of the carotid artery in German employees. We found out that this association is stronger in employees older than 50 years. In addition, it is independent of medical risk factors and stress caused by private issues.

Measures of infection prevention and incidence of SARS-CoV-2 infections in cancer patients undergoing radiotherapy in Germany, Austria and Switzerland.

PURPOSE: COVID-19 infection has manifested as a major threat to both patients and healthcare providers around the world. Radiation oncology institutions (ROI) deliver a major component of cancer treatment, with protocols that might span over several weeks, with the result of increasing susceptibility to COVID-19 infection and presenting with a more severe clinical course when compared with the general population. The aim of this manuscript is to investigate the impact of ROI protocols and performance on daily practice in the high-risk cancer patients during this pandemic. METHODS: We addressed the incidence of positive COVID-19 cases in both patients and health care workers (HCW), in addition to the protective measures adopted in ROIs in Germany, Austria and Switzerland using a specific questionnaire. RESULTS: The results of the questionnaire showed that a noteworthy number of ROIs were able to complete treatment in SARS-CoV­2 positive cancer patients, with only a short interruption. The ROIs reported a significant decrease in patient volume that was not impacted by the circumambient disease incidence, the type of ROI or the occurrence of positive cases. Of the ROIs 16.5% also reported infected HCWs. About half of the ROIs (50.5%) adopted a screening program for patients whereas only 23.3% also screened their HCWs. The range of protective measures included the creation of working groups, instituting home office work and protection with face masks. Regarding the therapeutic options offered, curative procedures were performed with either unchanged or moderately decreased schedules, whereas palliative or benign radiotherapy procedures were more often shortened. Most ROIs postponed or cancelled radiation treatment for benign indications (88.1%). The occurrence of SARS-CoV­2 infections did not affect the treatment options for curative procedures. Non-university-based ROIs seemed to be more willing to change their treatment options for curative and palliative cases than university-based ROIs. CONCLUSION: Most ROIs reported a deep impact of SARS-CoV­2 infections on their work routine. Modification and prioritization of treatment regimens and the application of protective measures preserved a well-functioning radiation oncology service and patient care.

Psychometric properties and contextual appropriateness of the German version of the Early Development Instrument.

BACKGROUND: Assessing the early development of children at a population level in educational settings, may be useful for public health and policy decision making. In this study, we evaluated the psychometric properties and the contextual appropriateness of a German language version of the Early Development Instrument (EDI), a survey-based instrument originally developed in Canada, which assesses developmental vulnerability for children in preschool settings. METHODS: Sixty preschool teachers from six preschool organizations (22% of organizations contacted) in three cities in southwest Germany participated. They administered a German version of the EDI (GEDI) to 225 children (51% of eligible children). We assessed internal consistency, test-retest and interrater reliability. Preschool teachers assisted in determining face-validity by reviewing item coverage and comprehensibility. Exploratory factor analysis (EFA) was used to evaluate convergent validity. Concurrent validity was measured using correlations and agreements (Bland-Altman plots) between GEDI and other validated instrument scores. Additionally, we compared associations between GEDI domain scores and sociodemographic characteristics with similar associations in EDI studies worldwide. RESULTS: GEDI domains showed good to excellent internal consistency (0.73 < α > 0.99) and moderate to good test-retest and interrater reliability (0.50 to 0.81 and 0.48 to 0.71, respectively [p-value < 0.05]). Face validity was considered acceptable. EFA showed a factor structure similar to the original EDI. Correlations (range: 0.32 to 0.67) and agreements between GEDI scores and other German language instruments suggested good external reliability. Scoring within the lowest 10th percentile was strongly associated with age. CONCLUSIONS: Our psychometric assessment suggests good reliability and consistency of the GEDI. Differences in the age distribution of children, pedagogical objectives and educational system features of German preschools require future work to determine score thresholds indicative of vulnerability. Aside from dropping selected items from the original EDI that were inconsistent with features of the German educational system, the distribution of values in the language and cognitive development domain also suggested that context-specific cut-offs must be established for the German version. Such efforts are needed to account for relevant contextual differences between the educational systems.

Associations of Changes in Organizational Justice with Job Attitudes and Health-Findings from a Prospective Study Using a Matching-Based Difference-in-Difference Approach.

BACKGROUND: Ample evidence indicates that unfairness at the workplace (organizational injustice) is associated with both job attitudes and health of employees. Several factors that influence these associations have been identified: e.g., personality traits, such as the Big Five traits, justice sensitivity, type of occupation (e.g., white-collar), and unobserved time-invariant factors. Previous studies only addressed parts of these issues, and the ideal research design to mitigate biases-an experiment with random assignment to a treatment and control group-is not feasible. This study therefore mimics a randomized experiment using two statistical techniques. METHODS: First, matching was implemented to balance the treatment and control group in confounding factors (demographics and personality) in two prospective waves (2012-2014) of observational data (4522 white-collar, 2984 blue-collar) taken from the Linked Personnel Panel, which is an employee survey representative for German private sector companies with more than 50 employees. Second, a difference-in-difference approach excludes unobserved time-invariant factors by estimating associations of changes in organizational justice (distributive, procedural, interactional) with job attitudes (job satisfaction, turnover intention) and health (general and mental) in these groups, separate for white- and blue-collar employees. RESULTS: A decrease in perceived justice was associated with lower job attitudes (less job satisfaction and higher turnover intentions), while an increase was associated with higher values. This pattern was found for white- and blue-collar workers and also for health indicators, with the latter, however, being less pronounced. CONCLUSIONS: Increased fairness at the workplace is related to better job attitudes and health for white- and blue-collar employees, independent of personality traits and unobserved time-invariant factors.

Identification of starting points to promote health and wellbeing at the community level - a qualitative study.

BACKGROUND: As health is influenced by the social, economic and environmental conditions in which individuals live, local communities are an ideal setting to promote health and wellbeing. However, up to now various health promotion interventions at the community level have had limited success, perhaps related to an incomplete understanding of local contexts and priorities. We therefore aimed to develop a broader and deeper understanding of topics or issues that were most salient to residents of a South-West German community by exploring their perceptions of needs, challenges, barriers and existing resources related to health and well-being. METHODS: As an initial step of a multi-year community-based participatory research project, we conducted semi-structured interviews with key informants (n = 30) from various community settings (e.g., child care, elderly care, businesses, non-profit organizations, village councils, and local government). The terms "health" and "wellbeing" were included in the stem of each question in the semi-structured interview guide to enable a focus on related perceived needs, challenges, barriers and existing resources. Interviews were audiotaped, transcribed verbatim and analyzed using qualitative content analysis techniques. RESULTS: Themes emerging from our interviews appeared to center primarily in three distinct areas: natural resources and built environment, access to services, and social cohesion including subthemes on the importance of social engagement and volunteerism, sense of community, and shared identity. CONCLUSIONS: That health and wellbeing were not identified explicitly as a priority by key informants suggests that these should not be presented as the primary focus of a community-wide initiative. Instead themes with a higher priority should be addressed in ways that can lead to better health and wellbeing as a secondary goal.

Associations of ambivalent leadership with distress and cortisol secretion.

Ambivalent social ties, i.e., whereby a relationship is evaluated simultaneously in positive and negative terms, are a potential source of distress and can perturb health-relevant biological functions. Social interactions at the workplace, in particular with supervisors, are often described in ambivalent terms, but the psychological and psychobiological impact of such interactions has received little scientific attention. The current study examined associations between ambivalent attitudes towards one's supervisor, perceived distress (general and work-related), and diurnal dynamics of the stress hormone cortisol. 613 employees evaluated their supervisor in terms of positive and negative behaviors, which was combined into an ambivalent index. Higher ambivalence was associated with higher perceived distress and work-related stress (p < .001), and with a larger cortisol awakening response and higher day-time secretion post-awakening (p < .01). The present study is the first to identify ambivalence towards supervisors as a predictor of employee distress and stress-related endocrine dysregulation. In consequence, focusing solely on positive or negative leader behavior may insufficiently capture the true complexity of workplace interactions and attempts to compensate negative behaviors with positive are unlikely to reduce distress-but quite the opposite-by increasing ambivalence.

Effects of low-volume high-intensity interval training in a community setting: a pilot study.

PURPOSE: High-intensity interval training (HIIT) is emerging as an effective and time-efficient exercise strategy for health promotion. However, most HIIT studies are conducted in laboratory settings and evidence regarding the efficacy of time-efficient "low-volume" HIIT is based mainly on demanding "all-out" protocols. Thus, the aim of this pilot study was to assess the feasibility and efficacy of two low-volume (≤ 30 min time-effort/week), non-all-out HIIT protocols, performed 2 ×/week over 8 weeks in a community-based fitness centre. METHODS: Thirty-four sedentary men and women were randomised to either 2 × 4-min HIIT (2 × 4-HIIT) or 5 × 1-min HIIT (5 × 1-HIIT) at 85-95% maximal heart rate (HRmax), or an active control group performing moderate-intensity continuous training (MICT, 76 min/week) at 65-75% HRmax. RESULTS: The exercise protocols were well tolerated and no adverse events occurred. 2 × 4-HIIT and 5 × 1-HIIT exhibited lower dropout rates (17 and 8 vs. 30%) than MICT. All training modes improved VO2max (2 × 4-HIIT: + 20%, P < 0.01; 5 × 1-HIIT: + 27%, P < 0.001; MICT: + 16%, P < 0.05), but the HIIT protocols required 60% less time commitment. Both HIIT protocols and MICT had positive impact on cholesterol profiles. Only 5 × 1-HIIT significantly improved waist circumference (P < 0.05) and subjective work ability (P < 0.05). CONCLUSIONS: The present study indicates that low-volume HIIT can be feasibly implemented in a community-based setting. Moreover, our data suggest that practical (non-all-out) HIIT that requires as little as 30 min/week, either performed as 2 × 4-HIIT or 5 × 1-HIIT, may induce significant improvements in VO2max and cardiometabolic risk markers.

Applied immuno-epidemiological research: an approach for integrating existing knowledge into the statistical analysis of multiple immune markers.

BACKGROUND: Immunologists often measure several correlated immunological markers, such as concentrations of different cytokines produced by different immune cells and/or measured under different conditions, to draw insights from complex immunological mechanisms. Although there have been recent methodological efforts to improve the statistical analysis of immunological data, a framework is still needed for the simultaneous analysis of multiple, often correlated, immune markers. This framework would allow the immunologists' hypotheses about the underlying biological mechanisms to be integrated. RESULTS: We present an analytical approach for statistical analysis of correlated immune markers, such as those commonly collected in modern immuno-epidemiological studies. We demonstrate i) how to deal with interdependencies among multiple measurements of the same immune marker, ii) how to analyse association patterns among different markers, iii) how to aggregate different measures and/or markers to immunological summary scores, iv) how to model the inter-relationships among these scores, and v) how to use these scores in epidemiological association analyses. We illustrate the application of our approach to multiple cytokine measurements from 818 children enrolled in a large immuno-epidemiological study (SCAALA Salvador), which aimed to quantify the major immunological mechanisms underlying atopic diseases or asthma. We demonstrate how to aggregate systematically the information captured in multiple cytokine measurements to immunological summary scores aimed at reflecting the presumed underlying immunological mechanisms (Th1/Th2 balance and immune regulatory network). We show how these aggregated immune scores can be used as predictors in regression models with outcomes of immunological studies (e.g. specific IgE) and compare the results to those obtained by a traditional multivariate regression approach. CONCLUSION: The proposed analytical approach may be especially useful to quantify complex immune responses in immuno-epidemiological studies, where investigators examine the relationship among epidemiological patterns, immune response, and disease outcomes.

The streamlined Allostatic Load Index: a replication of study results.

According to the World Health Organization stress in the workplace is becoming a major challenge of employers worldwide. While perceived stress levels can be assessed by questionnaires there is growing evidence that stress-related wear and tear of our body can be measured by the Allostatic Load Index (ALI). In a sample of 12,477 German industrial employees (19.6% female, 18-65 years) self-rated stress was explored by the effort-reward imbalance (ERI) questionnaire. A voluntary health check included biomarkers such as diastolic blood pressure, waist circumference, glycosylated hemoglobin, low-density lipoprotein, and heart rate variability. Based on predefined subclinical cutoff values, a 5-variable ALI was calculated. Differences in ALI according to low (ERI ≤1.0) and high (ERI >1.0) stress levels were tested. The association of ERI and ALI was explored using logistic regression analysis controlling for multiple confounders. Employees perceiving high stress levels showed significant higher ALI scores (p < .001) compared to lower stressed employees. This association was stronger in men and independent of age. ALI was associated with work stress in adjusted models (OR 1.18 ± .08 [95% CI 1.03, 1.36]; p < .05). This study replicates former results in a large sample of industrial employees indicating that work stress is associated with a short form ALI.

"Drug-Survival"-Raten und Gründe für den Abbruch von Systemtherapien bei Psoriasis.

HINTERGRUND UND ZIELE: Mittelschwere bis schwere Psoriasis erfordert häufig eine langfristige systemische Behandlung. Die Therapietreue bezüglich eines Medika-ments (Überlebensrate, "Drug Survival") reflektiert dessen Wirksamkeit, Sicherheit sowie die Zufriedenheit mit der Behandlung und ist ein Indikator für den Therapieerfolg. Das Ziel der vorliegenden Studie was die Ermittlung der "Drug-Survival"-Raten sowie der Gründe für den Abbruch einer Behandlung mit Fumarsäureestern (fumaric acid esters, FAE), Methotrexat (MTX), Acitretin (ACI), Cyclosporin A (CyA), Adalimumab (ADA), Etanercept (ETA), Infliximab (INF) und Ustekinumab (UST) bei Patienten mit mittelschwerer bis schwerer Psoriasis. PATIENTEN UND METHODEN: Wir führten eine retrospektive Analyse an 373 Patienten durch, die im Zeitraum 1/2003-5/2014 insgesamt 696 Behandlungen an einem deutschen Universitätsklinikum erhalten hatten. ERGEBNISSE: Die unbereinigte Überlebenswahrscheinlichkeit war für UST am höchsten, gefolgt von ADA, ETA, INF, FAE, MTX, ACI und CyA. In der multivariaten Regressionsanalyse mit FAE als Referenz betrug die Hazard Ratio (HR) für einen Abbruch 0,14 (95 % Konfidenzintervall: 0,06-0,35) bei UST, 0,43 (0,26-0,73) bei ADA, 2,11 (1,14-3,91) bei ACI und 3,26 (1,44-7,39) bei CyA. Das "Drug Survival" von INF war länger, wenn es in Kombination mit MTX eingesetzt wurde (HR 2,87; 1,21-6,81). Traditionelle systemische Antipsoriatika sowie INF wurden am häufigsten aufgrund von Nebenwirkungen abgesetzt; alle anderen Biologika aufgrund ihrer Unwirksamkeit für kutane Psoriasis-Läsionen. SCHLUSSFOLGERUNGEN: "Drug-Survival"-Raten sollten bei der Therapieentscheidung berücksichtigt werden, um den Patienten eine bestmögliche Langzeitstrategie zu bieten.

Drug survival rates and reasons for drug discontinuation in psoriasis.

BACKGROUND AND OBJECTIVES: Moderate-to-severe psoriasis frequently requires long-term systemic therapy. Reflecting efficacy, safety, and treatment satisfaction, drug survival is an indicator of therapeutic success. The objective of the present study was to assess drug survival rates and reasons for discontinuation of fumaric acid esters (FAE), methotrexate (MTX), acitretin (ACI), cyclosporine A (CyA), adalimumab (ADA), etanercept (ETA), infliximab (INF), and ustekinumab (UST) in patients with moderate-to-severe psoriasis. PATIENTS AND METHODS: We performed a retrospective analysis of 373 patients who had received a total of 696 treatment courses at a German university hospital in the period 1/2003-5/2014. RESULTS: The crude probability of survival was highest for UST, followed by ADA, ETA, INF, FAE, MTX, ACI, and CyA. In multivariate regression analysis using FAE as reference, hazard ratios (HR) for discontinuation were 0.14 (95 % confidence interval: 0.06-0.35) for UST, 0.43 (0.26-0.73) for ADA, 2.11 (1.14-3.91) for ACI, and 3.26 (1.44-7.39) for CyA. INF showed longer survival when combined with MTX (HR 2.87, 1.21-6.81). Traditional systemic antipsoriatic agents as well as INF were most frequently discontinued due to adverse events; all other biologics, due to inefficacy with respect to cutaneous lesions. CONCLUSIONS: Drug survival rates should be integrated into therapeutic decisions in order to provide patients with an optimal long-term strategy.

Elevated HbA(1c) levels and the accumulation of differentiated T cells in CMV(+) individuals.

AIMS/HYPOTHESIS: Biological ageing of the immune system, or immunosenescence, predicts poor health and increased mortality. A hallmark of immunosenescence is the accumulation of differentiated cytotoxic T cells (CD27(-)CD45RA(+/-); or dCTLs), partially driven by infection with the cytomegalovirus (CMV). Immune impairments reminiscent of immunosenescence are also observed in hyperglycaemia, and in vitro studies have illustrated mechanisms by which elevated glucose can lead to increased dCTLs. This study explored associations between glucose dysregulation and markers of immunosenescence in CMV(+) and CMV(-) individuals. METHODS: A cross-sectional sample of participants from an occupational cohort study (n = 1,103, mean age 40 years, 88% male) were assessed for HbA(1c) and fasting glucose levels, diabetes, cardiovascular risk factors (e.g. lipids), numbers of circulating effector memory (EM; CD27(-)CD45RA(-)) and CD45RA re-expressing effector memory (EMRA; CD27(-)CD45RA(+)) T cells, and CMV infection status. Self-report and physical examination assessed anthropometric, sociodemographic and lifestyle factors. RESULTS: Among CMV(+) individuals (n = 400), elevated HbA(1c) was associated with increased numbers of EM (B = 2.75, p < 0.01) and EMRA (B = 2.90, p < 0.01) T cells, which was robust to adjustment for age, sex, sociodemographic variables and lifestyle factors. Elevated EM T cells were also positively associated with total cholesterol (B = 0.04, p < 0.05) after applying similar adjustments. No associations were observed in CMV(-) individuals. CONCLUSIONS/INTERPRETATION: The present study identified consistent associations of unfavourable glucose and lipid profiles with accumulation of dCTLs in CMV(+) individuals. These results provide evidence that the impact of metabolic risk factors on immunity and health can be co-determined by infectious factors, and provide a novel pathway linking metabolic risk factors with accelerated immunosenescence.

Injustice at work and leukocyte glucocorticoid sensitivity: findings from a cross-sectional study.

OBJECTIVE: Organizational justice refers to perceived fairness at the workplace. Low organizational justice has been identified as a major source of distress and a predictor of poor health. Impaired regulation of immunological and inflammatory pathways may, in part, underlie these health effects. The present study investigated the association of organizational justice with leukocyte glucocorticoid sensitivity in vivo. METHODS: Organizational justice was assessed among 541 male factory workers (mean [standard deviation] age = 46 [9] years) by questionnaire. Cortisol release was measured at three time points before blood collection and summed as the area under the curve. Blood was used to assess leukocyte (white blood cell [WBC] count) subsets (neutrophils [%WBC], lymphocytes [%WBC], and the neutrophil/lymphocyte ratio). Glucocorticoid sensitivity was operationalized as the correlation between cortisol release and these hematologic parameters. Associations were adjusted for demographics, work characteristics, and life-style variables. RESULTS: A dose-response relationship between organizational justice and glucocorticoid sensitivity was found. Cortisol and hematologic parameters showed the expected significant association among individuals reporting high (all ß values ≥ |.26|; all p values ≤.001) or medium organizational justice (all ß values ≥ |.15|; all p values ≤.050), but not among those reporting low organizational justice (all ß values ≤ |.04|; all p values > .10). These regression slopes differed significantly between organizational justice groups (p values for interaction < .050). CONCLUSIONS: Low justice at work is associated with an impaired ability of endogenous cortisol to regulate leukocyte distribution in vivo. These findings identify a novel biological pathway by which organizational justice may affect health.

A streamlined approach for assessing the Allostatic Load Index in industrial employees.

Work stress is common and can lead to various bodily dysfunctions. The Allostatic Load Index (ALI) is a tool to measure the wear and tear of the body caused by chronic stress. This cross-sectional study aimed to explore the association of work-related stress and ALI in German industrial employees. A short form ALI should be developed for practical use of company physicians. In this exploration of an industrial cohort (n = 3797; 79.3% male), work stress was measured by the effort-reward imbalance (ERI) questionnaire in 2009-2011. ALI was calculated using 15 variables including anthropometric data, heart rate variability, as well as blood and urine samples based on predefined subclinical cut-off values. Differences in ALI related to low (≤1) and high (>1) ERI categories were tested. Logistic regression models estimated odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for the association between ALI and work stress controlling for multiple confounders. Employees exposed to high work stress showed higher ALI scores (p < 0.001) compared to those with low stress levels. In multivariable models, ALI was associated with work stress (OR 1.19 [95% CI: 1.00, 1.42]; p < 0.05) following adjustment for a range of potential confounders. By reducing ALI parameters to five variables this association increased modestly and remained statistically significant (OR 1.27 [95% CI: 1.05, 1.54]; p < 0.05). The results indicate that work stress is associated with ALI in German industrial employees. A short form index seems to be a promising approach for occupational health practitioners. The results should be validated in further longitudinal explorations defining a standard set of variables including gender-related thresholds.

Organizational justice is related to heart rate variability in white-collar workers, but not in blue-collar workers-findings from a cross-sectional study.

BACKGROUND: Perceived injustice at work predicts coronary heart disease. Vagal dysregulation represents a potential psychobiological pathway. PURPOSE: We examined associations between organizational justice and heart rate variability (HRV) indicators. Grounded in social exchange and psychological contract theory, we tested predictions that these associations are more pronounced among white-collar than among blue-collar workers. METHODS: Cross-sectional data from 222 blue-collar and 179 white-collar men were used. Interactional and procedural justice were measured by questionnaire. Ambulatory HRV was assessed across 24 h. Standardized regression coefficients (ß) were calculated. RESULTS: Among white-collar workers, interactional justice showed positive relationships with 24-h HRV, which were strongest during sleeping time (adjusted ßs≥0.26; p values≤0.01). No associations were found for blue-collar workers. A comparable but attenuated pattern was observed for procedural justice. CONCLUSIONS: Both dimensions of organizational injustice were associated with lowered HRV among white-collar workers. The impact of justice and possibly its association with health seems to differ by occupational groups.

Within- and between-group regression for improving the robustness of causal claims in cross-sectional analysis.

BACKGROUND: A major objective of environmental epidemiology is to elucidate exposure-health outcome associations. To increase the variance of observed exposure concentrations, researchers recruit individuals from different geographic areas. The common analytical approach uses multilevel analysis to estimate individual-level associations adjusted for individual and area covariates. However, in cross-sectional data this approach does not differentiate between residual confounding at the individual level and at the area level. An approach allowing researchers to distinguish between within-group effects and between-group effects would improve the robustness of causal claims. METHODS: We applied an extended multilevel approach to a large cross-sectional study aimed to elucidate the hypothesized link between drinking water pollution from perfluoroctanoic acid (PFOA) and plasma levels of C-reactive protein (CRP) or lymphocyte counts. Using within- and between-group regression of the individual PFOA serum concentrations, we partitioned the total effect into a within- and between-group effect by including the aggregated group average of the individual exposure concentrations as an additional predictor variable. RESULTS: For both biomarkers, we observed a strong overall association with PFOA blood levels. However, for lymphocyte counts the extended multilevel approach revealed the absence of a between-group effect, suggesting that most of the observed total effect was due to individual level confounding. In contrast, for CRP we found consistent between- and within-group effects, which corroborates the causal claim for the association between PFOA blood levels and CRP. CONCLUSION: Between- and within-group regression modelling augments cross-sectional analysis of epidemiological data by supporting the unmasking of non-causal associations arising from hidden confounding at different levels. In the application example presented in this paper, the approach suggested individual confounding as a probable explanation for the first observed association and strengthened the robustness of the causal claim for the second one.

The Association of (Effective and Ineffective) Analgesic Intake, Pain Interference and Heart Rate Variability in a Cross-Sectional Occupational Sample.

OBJECTIVE: Persistent pain is associated with dysfunction of the autonomic nervous system, in particular a loss of vagal inhibitory control, that can be indexed by decreased vagally mediated heart rate variability (vmHRV). Effective treatment (e.g., analgesic self-medication) may lead to a restoration of vmHRV. The objective of this article was to further explore the relationship of pain and vagal control and to investigate the effect of analgesic self-medication on the association of vmHRV and pain. METHODS: We used a large cross-sectional data set on pain ratings and analgesic intake from the Mannheim Industrial Cohort Study for secondary analysis. The root mean square of successive differences, a measure of vmHRV corresponding to the parasympathetic regulation of the heart, was derived from 24-hour electrocardiogram recordings. RESULTS: The frequency of analgesic intake and interference of pain are significantly associated. Individuals that report greater pain interference with their normal work routine (including both work outside the home and housework) and frequent analgesic intake have significantly lower vmHRV. Subjects with ineffective analgesic intake (reporting great pain interference and high frequent analgesic intake) had the lowest vmHRV. Individuals effectively taking analgesics (reporting no or low pain interference and high frequent analgesic intake) showed greater vmHRV compared to those ineffectively taking. Analysis revealed significant differences and linear trends on vmHRV between all groups. CONCLUSION: In line with previous research, vmHRV is inversely associated with pain interference. Analgesic intake mediates the association of vmHRV and pain. Effective analgesic self-medication may lead to a restoration in vmHRV. These results further support the vagus nerve as an objective indication of pain severity and treatment efficacy in patients with persistent pain.

Association of vitamin D levels with type 2 diabetes in older working adults.

OBJECTIVES: Increasing evidence suggests that vitamin D plays a role in the development of chronic diseases including type 2 diabetes (DM). Aim of the study was to explore the association of vitamin D levels with prevalent DM in a sample of predominantly healthy working adults older than 45 years. METHODS: This cross-sectional study (2009-2011) involved 1821 employees of a German engineering company (83.1% male, mean age 51.9 ±5.6 years). Sociodemographics and medical history were assessed by self-report. Clinical characteristics were obtained including blood samples to determine vitamin D levels and diabetes status by fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c). Vitamin D was grouped into one of four categories (<10 ng/ml, 10-19.9 ng/ml, 20-29.9 ng/ml, ≥30 ng/ml). Bivariate associations between vitamin D categories and a composite indicator for DM (FPG ≥126 mg/dl or HbA1c ≥6.5% or self-reported diagnosis) were calculated; multivariable models tested this association further, controlling for potential confounders. RESULTS: Severe vitamin D deficiency (<10 ng/ml) was associated with increasing FPG (ß 3.13; 95% CI: 0.78, 5.47; p≤0.01) and HbA1c (ß 0.15; 95% CI: 0.08, 0.23; p≤0.001) values in adjusted linear regression models. In multivariable models, severe vitamin D deficiency was associated with DM (OR 2.55; 95%CI 1.16, 5.62; p≤0.05) after controlling for potential confounders. CONCLUSIONS: Vitamin D deficiency is associated with prevalent DM in working older adults. The findings highlight that the workplace may be a unique location for conducting large-scale health screening to identify those at risk of DM using vitamin D.

Consistent associations between measures of psychological stress and CMV antibody levels in a large occupational sample.

Cytomegalovirus (CMV) is a herpes virus that has been implicated in biological aging and impaired health. Evidence, largely accrued from small-scale studies involving select populations, suggests that stress may promote non-clinical reactivation of this virus. However, absent is evidence from larger studies, which allow better statistical adjustment for confounding and mediating factors, in more representative samples. The present study involved a large occupational cohort (N=887, mean age=44, 88% male). Questionnaires assessed psychological (i.e., depression, anxiety, vital exhaustion, SF-12 mental health), demographic, socioeconomic (SES), and lifestyle variables. Plasma samples were analyzed for both the presence and level of CMV-specific IgG antibodies (CMV-IgG), used as markers for infection status and viral reactivation, respectively. Also assessed were potential biological mediators of stress-induced reactivation, such as inflammation (C-reactive protein) and HPA function (awakening and diurnal cortisol). Predictors of CMV infection and CMV-IgG among the infected individuals were analyzed using logistic and linear regression analyses, respectively. Confirming prior reports, lower SES (education and job status) was positively associated with infection status. Among those infected (N=329), higher CMV-IgG were associated with increased anxiety (ß=.14, p<.05), depression (ß=.11, p=.06), vital exhaustion (ß=.14, p<.05), and decreased SF-12 mental health (ß=-.14, p<.05), adjusting for a range of potential confounders. Exploratory analyses showed that these associations were generally stronger in low SES individuals. We found no evidence that elevated inflammation or HPA-function mediated any of the associations. In the largest study to date, we established associations between CMV-IgG levels and multiple indicators of psychological stress. These results demonstrate the robustness of prior findings, and extend these to a general working population. We propose that stress-induced CMV replication warrants further research as a psychobiological mechanism linking stress, aging and health.