High-protein meal challenge reveals the association between the salivary cortisol response and metabolic syndrome in police officers

Modeling the relationship between shift work and cardiometabolic risk through circadian disruption, sleep and stress pathways

The purpose of this study is to elucidate the multiple pathways linking shift work exposure to cardiometabolic risk (CMR) through the intermediates of circadian disruption, sleep disturbances, and stress. A cross-sectional study was conducted at Kingston Health Sciences Center that included female hospital workers, 160 who worked a day-only schedule and 168 who worked rotating days and nights. Participants completed questionnaires, a clinical exam, and wore accelerometers to collect sleep data for 8 days. Participants also collected urine samples at each void during a 24-h collection period, on the day shift for day-only workers and the night shift for rotating shift workers, for cortisol and melatonin measures. We adapted and tested a conceptual model proposed by Knutsson and Boggild for circadian disruption, sleep, and stress mechanistic pathways linking shift work to CMR using structural equation modeling techniques. Status as a rotating shift worker was associated with increased circadian disruption of cortisol and melatonin production compared to day-only workers (P < .001). Increased circadian disruption was associated with an increased CMR (P = .01). Rotating shift work was associated with sleep disturbances (P = .002) and increased job stress (P < .001), but neither was associated with CMR. We conclude that rotating shift work is associated indirectly with increased CMR. This association is mediated by circadian disruption as indicated by attenuated melatonin and cortisol, and flatter cortisol curves.

Metabolic Syndrome Prevalence among Armed Forces Personnel (Military Personnel and Police Officers): A Systematic Review and Meta-Analysis

INTRODUCTION

Metabolic syndrome (MetS) is closely linked to type 2 diabetes and cardiovascular disease. Various studies have reported the prevalence of MetS in different armed forces personnel in different countries. However, performing a systematic review and meta-analysis on this subject seems necessary. The aim of this study was to estimate the pooled prevalence of MetS among armed forces personnel including members of the military and police forces.

MATERIALS AND METHODS

A systematic review was carried out on all associated papers published in PubMed, Scopus, Web of Science and Cochrane Library, encompassing the timeframe: November, 2018 to January 2000. The overall prevalence of MetS, and its prevalence based on different diagnostic criteria [National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III), American Heart Association (AHA) and International Diabetes Federation (IDF)] were pooled using a random-effects model.

RESULTS

Twenty five eligible studies were selected for the meta-analysis. Among all police officers contained in this study group, the overall prevalence of MetS was 26.2% (95% CI: 19.7-34%; Q = 229.45, p = 0.00). Among different military personnel contained in this study group, the overall estimation of MetS prevalence was 8.3% (95% CI: 6.3-11%; Q = 540.88, p = 0.00) the prevalence of MetS was 8.0% (95% CI: 5.7-11%; Q = 409.76, p = 0.00) according to the NCEP-ATP III criterion.

CONCLUSION

The findings from the present meta-analyses displayed a low prevalence of metabolic syndrome in armed forces in general. These findings will allow healthcare providers and policy-makers to find solutions in order to take action to reduce MetS risks on a wider scale, especially among police officers.

Subclinical Markers of Cardiovascular Disease Among Police Officers: A Longitudinal Assessment of the Cortisol Awakening Response and Flow Mediated Artery Dilation

OBJECTIVE

To examine the association of the cortisol awakening response (CAR) with change in brachial artery flow-mediated dilation (FMD%) in police officers over a 7-year period.

METHODS

Baseline CAR was obtained from four saliva samples taken 15 minutes apart immediately after awakening. Analysis of covariance was used to compare the change in FMD% (FMD%Follow-up-FMD%Baseline) across tertiles of area under the cortisol curve with respect to increase (AUCI). Regression analysis was use to assess trend.

RESULTS

Officers (n = 172; 81% men) had a mean ± SD age of 41 ± 7.6 years. Men in the lowest AUCI tertile (ie, atypical waking cortisol pattern) had a significantly larger 7-year mean decline in FMD% (mean ± SE: -2.56 ± 0.64) compared with men in the highest tertile (-0.89 ± 0.69) (P = 0.0087).

CONCLUSIONS

An awakening cortisol AUCI predicted worsening of FMD% approximately 7 years later among male officers.

Social avoidance in policing: Associations with cardiovascular disease and the role of social support

PURPOSE

The purpose of this paper is to examine the association of social avoidance among police, cardiovascular disease (CVD) (metabolic syndrome (MetSyn)), and social support.

DESIGN/METHODOLOGY/APPROACH

Participants were officers from the Buffalo Cardio-Metabolic Occupational Police Stress study (n = 289). Social avoidance (defined as the tendency to avoid social contact) and other subscales from the Cook-Medley Hostility Scale were analyzed. The mean number of MetSyn components across tertiles of the Cook-Medley scales was computed using analysis of variance and analysis of covariance. Social support was measured with the Social Provisions Scale, categorized as high or low based on the median.

FINDINGS

The mean number of MetSyn components increased significantly across tertiles of social avoidance (1.51 ± 0.18, 1.52 ± 0.12, and 1.81 ± 0.12); the only Cook-Medley subscale that remained significantly associated with MetSyn following adjustment for age and gender. Participants high in social avoidance reported significantly lower social support (79.9 ± 8.5 vs 85.8 ± 8.6; p = 0.001).

RESEARCH LIMITATIONS/IMPLICATIONS

The study is cross-sectional and therefore precludes causality. The authors were unable to determine the direction of associations between social avoidance and MetSyn. The measure of social support was unidimensional, including only perceived support; additional types of social support measures would be helpful.

PRACTICAL IMPLICATIONS

This study suggests that occupational-based police social isolation is associated with health outcomes and lower support. Several suggestions are made which will help to improve communication between the police and public. Examples are the use of social media, training in communication techniques, and changing the police role to one of public guardians.

ORIGINALITY/VALUE

Social avoidance is the least studied the Cook-Medley subscale associated with CVD. It is important for the health of officers to maintain a social connection with others.

Salivary cortisol and α-amylase: subclinical indicators of stress as cardiometabolic risk

Currently, the potential for cardiovascular (CV) stress-induced risk is primarily based on the theoretical (obvious) side effects of stress on the CV system. Salivary cortisol and α-amylase, produced respectively by the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic-adrenomedullary (SAM) system during stress response, are still not included in the routine evaluation of CV risk and require additional and definitive validation. Therefore, this article overviews studies published between 2010 and 2015, in which salivary cortisol and α-amylase were measured as stress biomarkers to examine their associations with CV/CMR (cardiometabolic risk) clinical and subclinical indicators. A comprehensive search of PubMed, Web of Science and Scopus electronic databases was performed, and 54 key articles related to the use of salivary cortisol and α-amylase as subclinical indicators of stress and CV/CMR factors, including studies that emphasized methodological biases that could influence the accuracy of study outcomes, were ultimately identified. Overall, the biological impact of stress measured by salivary cortisol and α-amylase was associated with CV/CMR factors. Results supported the use of salivary cortisol and α-amylase as potential diagnostic tools for detecting stress-induced cardiac diseases and especially to describe the mechanisms by which stress potentially contributes to the pathogenesis and outcomes of CV diseases.

Work Stress and Metabolic Syndrome in Police Officers. A Prospective Study

OBJECTIVE

The aim of this longitudinal study was to evaluate the association between occupational stress and metabolic syndrome (MetS) in a rapid response police unit.

METHOD

Work-related stress was continuously monitored during the 5-year period with both the Demand-Control-Support (DCS) and the Effort-Reward Imbalance (ERI) models. Blood pressure, body mass index (BMI), waist circumference, triglycerides, HDL-cholesterol, and fasting blood glucose were measured at baseline in January 2009, and in January 2014. 234 out of 290 police officers (81%) completed the follow-up.

RESULTS

The majority of police officers had high stress levels. At follow-up, police officers in the highest quartile of stress had significantly higher mean levels of triglycerides, and lower levels of HDL-cholesterol than their colleagues in the lowest quartile. Police officers with high stress had an increased adjusted risk of developing MetS (aOR = 2.68; CI95% = 1.08-6.70), and hypertriglyceridemia (aOR = 7.86; CI95 = 1.29-48.04). Demand and Effort were significant predictors of MetS.

CONCLUSION

Our study supports the hypothesis that work-related stress induces MetS, particularly through its effects on blood lipids. Future longitudinal studies with continuous monitoring of stress levels will definitively confirm this hypothesis.