The potential of using hair cortisol to measure chronic stress in occupational healthcare; a scoping review

OBJECTIVES: Workplace-based selective prevention of mental health problems currently relies on subjective evaluation of stress complaints. Hair cortisol captures chronic stress responses and could be a promising biomarker for the early identification of mental health problems. The objective was to provide an overview of the state-of-the-art knowledge on the practical value of hair cortisol in the occupational setting. METHODS: We performed a scoping review of cross-sectional and longitudinal studies in PubMed, Embase, and PsycINFO up to November 2019 assessing the relations of hair cortisol with work-related stressors, perceived stress, and mental health outcomes in healthy workers. RESULTS: We found five longitudinal studies, of which two observed an increase in work-related stressors to be associated with higher hair cortisol, one found a relation with lower hair cortisol and one did not find a relationship. Findings of cross-sectional studies were also mixed. The one available longitudinal study regarding mental health showed that hair cortisol was not related to depressive symptoms. CONCLUSIONS: Hair cortisol measurement within occupational health research is still in its early stage and more longitudinal studies are urgently needed to clarify its relationship with work-related stressors and perceived stress before hair cortisol can be used to identify workers at risk for mental health problems

Time-restricted feeding improves adaptation to chronically alternating light-dark cycles

Disturbance of the circadian clock has been associated with increased risk of cardio-metabolic disorders. Previous studies showed that optimal timing of food intake can improve metabolic health. We hypothesized that time-restricted feeding could be a strategy to minimize long term adverse metabolic health effects of shift work and jetlag. In this study, we exposed female FVB mice to weekly alternating light-dark cycles (i.e. 12 h shifts) combined with ad libitum feeding, dark phase feeding or feeding at a fixed clock time, in the original dark phase. In contrast to our expectations, long-term disturbance of the circadian clock had only modest effects on metabolic parameters. Mice fed at a fixed time showed a delayed adaptation compared to ad libitum fed animals, in terms of the similarity in 24 h rhythm of core body temperature, in weeks when food was only available in the light phase. This was accompanied by increased plasma triglyceride levels and decreased energy expenditure, indicating a less favorable metabolic state. On the other hand, dark phase feeding accelerated adaptation of core body temperature and activity rhythms, however, did not improve the metabolic state of animals compared to ad libitum feeding. Taken together, restricting food intake to the active dark phase enhanced adaptation to shifts in the light-dark schedule, without significantly affecting metabolic parameters

The moderating role of lifestyle, age, and years working in shifts in the relationship between shift work and being overweight.

Cross-sectional data were used of 2569 shift and 4848 non-shift production workers who participated between 2013 and 2018 in an occupational health check. Overweight (BMI ≥ 25 kg/m2) was calculated using measured weight and height; lifestyle was assessed by questionnaires. Multiple-adjusted logistic regression with interaction terms between shift work and potential moderators assessed multiplicative interaction; the relative excess risk due to interaction assessed additive interaction (synergism)

Shift work, and burnout and distress among 7798 blue-collar workers.

Objective: This study aimed to investigate the association between shift work, and burnout and distress, and differences by degree of satisfaction with shift schedule and its impact on private life. Methods: Population 4275 non-shift factory workers and 3523 rotating 5-shift workers. Workers participated between 2009 and 2016 one to three times in the companies’ periodical occupational health checks. Burnout was measured using the distance, exhaustion and competence subscales of the Dutch Maslach Burnout Inventory and distress by the subscale of the Four-Dimensional Symptom Questionnaire (scale: 0–100). Multiple-adjusted linear mixed models were used to assess between- and within-subject associations between shift work and outcomes, and differences by age, years of shift work, and satisfaction with and impact of shift schedule. Results: Shift work was significantly associated with lower scores on burnout distance (B − 1.0, 95% − 1.8 to 0.3), and among those aged ' 48 years with burnout exhaustion (range B − 1.3 to − 1.6). However, the effect sizes were small. Compared to non-shift workers, shift workers dissatisfied with their schedule and those experiencing a high impact on private life had significantly higher burnout (range B 1.7–6.3) and distress levels (range B 4.9–6.1). In contrast, satisfied shift workers and those experiencing a low impact of shift schedule had lower burnout (range B − 0.2 to − 2.2) and no difference in distress levels (P ≥ 0.05). No clear pattern by years of shift work was observed. Conclusions: Shift work was associated with burnout and distress in those who were dissatisfied with or who had perceived high impact on the private life of their shift schedule

Shift work and its relation with meal and snack patterns among healthcare workers.

Objective Unfavorable eating patterns might contribute to the adverse health effects of shift work. Our objective was to examine differences in meal and snack frequency, as well as the quality of snacks, between shift and day workers and between different types of shifts. Methods Cross-sectional data from 485 healthcare workers aged 18–65 years of the Klokwerk+ cohort study was used. Dietary intake was assessed using 3-day food diaries, and meals and snacks were classified by the food-based classification of eating episodes method. Using multivariable-adjusted regression analyses, we esti-mated differences in meal and snack frequency and the quality of snacks between shift and day workers. Within the shift working group, eating frequency on day, evening, and night shifts were compared to work-free days. Results Meal and snack frequency as well as the quality of snacks showed no significant differences between shift and day workers (P≥0.05). Shift workers had a higher frequency of high-quality snacks [β 0.29, 95% confidence interval (CI) 0.12–0.46] and a lower frequency of low-quality snacks (β-0.29, 95% CI-0.49–-0.09) on evening shifts compared to their work-free days. Compared to work-free days, shift workers had a higher frequency of high-quality snacks on days shifts (β 0.24, 95% CI 0.10–0.38), and only those aged ≤40 years had a higher frequency of snacks on night shifts (β 0.53, 95% CI 0.06–1.00) (interaction by age P<0.05). Conclusion This study observed no differences between day and shift workers either in meal and snack frequency or in the quality of snacks. However, snacking patterns differed across shifts. Future research should investigate whether these snacking patterns contribute to the adverse health effects of shift work

The mediating role of lifestyle in the relationship between shift work, obesity and diabetes.

In this cross-sectional study, 3188 shift workers and 6395 non-shift workers participated between 2013 and 2018 in periodical occupational health checks. Weight and height were objectively measured to calculate obesity (BMI ≥ 30 kg/m2). Diabetes status, physical activity, diet, smoking, and sleep quality were assessed using standardized questionnaires. Structural equation models adjusted for relevant confounders were used to analyze the mediating role of lifestyle in the relationships between shift work, and obesity and diabetes

Shift work, chronotype and the risk of cardiometabolic disturbances

Introduction Shift work has been associated with cardiometabolic risk factors, but the relation is not clear for all risk factors, and the role of chronotype is largely unknown. We examined associations between shift work and cardiometabolic risk factors, and explored these associations in different chronotypes. Methods Risk factors (anthropometry, blood pressure, lipids, glucose, gamma-glutamyltransferase, C-reactive protein, uric acid, and glomerular filtration rate) were assessed among 7768 adults in 1987–1991, with repeated measurements every five years. In the ongoing 6th examination wave data on shift work history have been collected, with data from 2013–2015 being available. In 2016, linear mixed models and logistic generalised estimating equations were used to estimate associations between shift work and risk factors one year later. Results Shift workers had more often overweight (OR: 1.44, 95% CI: 1.06–1.95) and a higher body mass index (BMI) (β: 0.56 kg/m2, 95% CI: 0.10–1.03) than day workers. A significant difference in BMI between day and shift workers was observed among evening chronotypes (β: 0.97 kg/m2, 95% CI: 0.21–1.73), but not among morning chronotypes (β: 0.04 kg/m2, 95% CI: −0.85–0.93). No other significant associations between shift work and risk factors were found in the chronotype strata, except for glucose among intermediate chronotypes (β: −0.36, 95% CI: −0.62–0.11). No differences by frequency of night shifts and duration of shift work were observed. Conclusions Shift workers, in particular evening chronotypes, have a higher risk of overweight than day workers. More research is however needed to verify our results, and establish whether tailored interventions by chronotype are wanted

The mediating role of lifestyle in the relationship between shift work, obesity and diabetes.

In this cross-sectional study, 3188 shift workers and 6395 non-shift workers participated between 2013 and 2018 in periodical occupational health checks. Weight and height were objectively measured to calculate obesity (BMI ≥ 30 kg/m2). Diabetes status, physical activity, diet, smoking, and sleep quality were assessed using standardized questionnaires. Structural equation models adjusted for relevant confounders were used to analyze the mediating role of lifestyle in the relationships between shift work, and obesity and diabetes

Work-related physical and psychosocial risk factors cluster with obesity, smoking and physical inactivity

OBJECTIVE: This study investigated associations between the co-existence of multiple types of work-related psychosocial and physical risk factors, and (1) obesity; (2) smoking; and (3) leisure-time physical inactivity. It also aimed to identify sociodemographic characteristics related to clustering of work-related risk factors and lifestyle factors. METHODS: Cross-sectional data on work-related risk factors (e.g., decision authority and repetitive movements) and lifestyle was measured using a standardized questionnaire among 52,563 Dutch workers in health care, services, manufacturing and public sector. Multiple-adjusted logistic regression models assessed associations between the co-existence of multiple types of psychosocial and physical risk factors and lifestyle factors. Additionally, logistic regression models related age, gender and educational level to clustering of risk factors and lifestyle factors. RESULTS: The co-existence of multiple types of work-related psychosocial risk factors was associated with higher odds of smoking and being physically inactive. For example, workers exposed to three psychosocial risk factors had a 1.55 times higher odds of being physically inactive (95%CI: 1.42-1.70) compared to unexposed workers. A higher number of physical risk factors was also significantly associated with higher odds of smoking and obesity. The co-existence of multiple types of physical risk factors was not associated with higher odds of physical inactivity. Clustering of work-related risk factors and at least one unhealthy lifestyle factor occurred in particular among workers with low educational level. CONCLUSIONS: Results imply that interventions are needed that focus on workers with a low educational level and address work-related physical and psychosocial risk factors as well as lifestyle