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

Lower diurnal HPA-axis activity in male hypertensive and coronary heart disease patients predicts future CHD risk

BACKGROUND

Coronary heart disease (CHD) and its major risk factor hypertension have both been associated with altered activity of the hypothalamus-pituitary-adrenal (HPA)-axis but the biological mechanisms underlying prospective associations with adverse disease outcomes are unclear. We investigated diurnal HPA-axis activity in CHD-patients, hypertensive (HT) and healthy normotensive men (NT) and tested for prospective associations with biological CHD risk factors.

METHODS

Eighty-three male CHD-patients, 54 HT and 54 NT men repeatedly measured salivary cortisol over two consecutive days. Prospective CHD risk was assessed by changes between baseline and follow-up in the prothrombotic factors D-dimer and fibrinogen, the pro-inflammatory measures interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and acute phase protein C-reactive protein (CRP), as well as blood lipids in terms of total cholesterol (tChol)/high-density-lipoprotein cholesterol (HDL)-ratio. We aggregated coagulation and inflammatory measures to respective indices.

RESULTS

The groups differed in repeated daytime cortisol (dayCort) secretion (p=.005,η² _p=.03,f=0.18) and cortisol awakening response (CAR) (p=.006,η² _p=.03,f=0.18), with similarly lower overall dayCort and CAR in CHD-patients and HT, as compared to NT. The groups differed further in cortisol at awakening (p=.015,η² _p=.04,f=0.20) with highest levels in HT (p´s≤.050), and in diurnal slope between waking and evening cortisol (p=.033,η² _p=.04,f=0.20) with steepest slopes in HT (p´s≤.039), although in part not independent of confounders. Lower aggregated dayCort and CAR in terms of area-under-the-curve (AUC) independently predicted increases in future overall CHD risk (AUC_dayCort: p=.021,η² _p=.10,f=0.33;AUC_CAR: p=.028,η² _p=.09,f=0.31) 3.00 ± 0.06(SEM) years later, with risk prediction most pronounced in fibrinogen (AUC_dayCort: p=.017,ΔR ²= 0.12;AUC_CAR: p=.082).

CONCLUSION

We found evidence for an HPA-axis hypoactivity in CHD and HT with lower diurnal HPA-axis activity predicting increases in cardiovascular risk as evidenced by increases in circulating levels of biomarkers of atherothrombotic risk. Down-regulation of basal HPA-axis activity may contribute to the pathogenesis of atherosclerosis and thrombosis in CHD via effects on coagulation.

Demographic and Health Characteristics of Older Latino Birth Cohorts in the Health and Retirement Study

OBJECTIVES

Latinos are the fastest aging racial/ethnic minority group in the United States. One limitation to understanding the diverse experiences of older Latinos is the lack of nationally representative data necessary to examine factors contributing to changes in population-level health over time. This is needed to provide a more comprehensive picture of the demographic characteristics that influence the health and well-being of older Latinos.

METHODS

We utilized the steady-state design of the Health and Retirement Study (HRS) from 1992 to 2016 to examine the demographic and health characteristics of five entry birth cohorts of older Latinos aged 51-56 years (n = 2,882). Adjusted Wald tests were used to assess statistically significant differences in demographic and health characteristics across the HRS birth cohorts.

RESULTS

Cross-cohort comparisons of demographic and health characteristics of older Latinos indicate significant change over time, with later-born HRS birth cohorts less likely to identify as Mexican-origin, more likely to identify as a racial "other," and more likely to be foreign-born. In addition, we find that later-born cohorts are more educated and exhibit a higher prevalence of hypertension, diabetes, and obesity.

DISCUSSION

Increasing growth and diversity among the older U.S. Latino population make it imperative that researchers document changes in the demographic composition and health characteristics of this population as it will have implications for researchers, policymakers, health care professionals, and others seeking to anticipate the needs of this rapidly aging population.

Diurnal Cortisol Variation According to High-Risk Occupational Specialty Within Police: Comparisons Between Frontline, Tactical Officers, and the General Population

OBJECTIVE

The aim of this study was to compare diurnal salivary cortisol among high-risk occupational police specialties and the general population (n = 18,698).

METHODS

Tactical and frontline officers provided salivary cortisol samples for 2 days (four times: wake, 30 minutes, 11 hours, and 17 hours post-awakening) and were compared with a general population sample of group field studies utilizing similar methodology. Samples were analyzed for free cortisol concentrations (nmol/L) using chemiluminescence immunoassay.

RESULTS

Repeated-measures mixed-model analysis of variance (ANOVA) revealed significantly greater salivary diurnal cortisol among tactical than frontline officers. Furthermore, both tactical and frontline officers had higher cortisol levels on average at all time points than the general population sample.

CONCLUSION

Results suggest that diurnal cortisol response may be associated with level of risk exposure in hazardous occupational subspecialties within policing compared with the general population.

Influence of cortisol awakening response on telomere length: Trends for males and females

Although telomere attrition is associated with the process of normal ageing, shorter telomere length (TL) has been associated with acute and chronic stressors. A neurobiological factor hypothesised to be responsible for this accelerated attrition is the dysregulation of the cortisol stress response, which can induce DNA damage affecting DNA telomeric caps. Marked sex differences are reported in both the cortisol stress response and telomere dynamics, yet no explicit investigation of sex specificity on the relationship between cortisol and TL exists. This study used mathematical equation modelling to describe the relationship between diurnal cortisol levels and telomere length within the context of sex, in a healthy population. Cortisol awakening responses (CAR) were measured via ELISA methodology in fifty-one healthy participants (28 males, 23 females). qPCRs determined TL from genomic DNA extracted from saliva. To assess the effect of free cortisol on relative TL ratio, a semi-log regression plot of the two variables trended for sex were fitted using spline curves. Results demonstrated significant differences between males and females in the relationship defining CAR and TL association (p = 0.03). These results suggest the relationship is not linear and can be represented as a complex arcsin function, and that the patterns are opposite in males and females. Males demonstrate a positive correlation, with higher levels of CAR being associated with longer telomere sequences. Females demonstrated a negative correlation. Future studies must carefully take into consideration moderating factors such as sex, and sex hormones across the lifespan when investigating telomere length.

Individual differences in glucocorticoid regulation: Does it relate to disease risk and resilience?

Glucocorticoid (GC) signaling varies among individuals, and this variation may relate to individual differences in health outcomes. To determine if and which aspects of signaling (basal, circadian, integrative, or reactivity) are associated with specific health outcomes, we reviewed recent studies that relate GCs to health outcomes. We identified papers through PubMed and reviewed 100 original research articles related to mental health, cardiovascular health, cancer, diabetes, obesity, pulmonary health, sleep, and fitness. Many studies reported elevated GC secretion associated with worse health, but this was only particularly true for integrative GC measures. On the other hand, accentuated cortisol awakening response and a steeper circadian rhythm were both associated with positive health outcomes. Overall, relationships between GC secretion and health outcomes were relatively weak. This systematic review of relationships between GC metrics and health outcomes highlights the importance of careful consideration when selecting methods to measure GC regulation in health research.

The Impact of Acute Stress Physiology on Skilled Motor Performance: Implications for Policing

Investigations of police performance during acutely stressful situations have primarily focused on higher-order cognitive processes like attention, affect or emotion and decision-making, and the behavioral outcomes of these processes, such as errors in lethal force. However, behavioral outcomes in policing must be understood as a combination of both higher-order processes and the physical execution of motor skills. What is missing from extant police literature is an understanding of how physiological responses to acute stress contribute to observed decrements in skilled motor performance at the neuromuscular level. The purpose of the current paper is to fill this knowledge gap in the following ways: (1) review scientific evidence for the physiological (i.e., autonomic, endocrine, and musculoskeletal) responses to acutely stressful exposures and their influence on skilled motor performance in both human and animal models, (2) review applied evidence on occupationally relevant stress physiology and observed motor decrements in performance among police, and (3) discuss the implications of stress physiology for police training and identify future directions for applied researchers. Evidence is compelling that skill decay is inevitable under high levels of acute stress; however, robust evidence-informed training practices can help mitigate this decay and contribute to officer safety.