Anabolic hormone profiles in elite military men

Stabilization of Salivary Biomarkers

The use of saliva as a diagnostic biofluid has been increasing in recent years, thanks to the identification and validation of new biomarkers and improvements in test accuracy, sensitivity, and precision that enable the development of new noninvasive and cost-effective devices. However, the lack of standardized methods for sample collection, treatment, and storage contribute to the overall variability and lack of reproducibility across analytical evaluations. Furthermore, the instability of salivary biomarkers after sample collection hinders their translation into commercially available technologies for noninvasive monitoring of saliva in home settings. The present review aims to highlight the status of research on the challenges of collecting and using diagnostic salivary samples, emphasizing the methodologies used to preserve relevant proteins, hormones, genomic, and transcriptomic biomarkers during sample handling and analysis.

New Morphofunctional Criteria for Resistance Profile in Post-Traumatic Stress Disorder Models as Adrenal Dysfunction Trigger

For the first time in modeling posttraumatic stress disorder (PTSD), we have described the morphofunctional state of adrenal glands in Wistar rats resistant and sensitive to predator stress (rodent fear of the predator). Despite the evident signs of adrenal dysfunction in both phenotypes, we have discovered the thickening of undifferentiated cell zone and high indices of functional activity of stem cells in resistant animals, suggesting ample adaptation. The most important data demonstrate the direct relationship between the reduction of corticosterone and testosterone levels and adrenal dysfunction in PTSD models. The study results allow considering the adrenal stem cells as potential therapeutic targets.

Toward a "Dashboard" Indicator of Retention in U.S. Navy Personnel

INTRODUCTION

Retention is a top priority for the U.S. Navy. However, our understanding of factors influencing retention of Navy personnel is limited. Current research implies that poor mental health, low appraisals of unit cohesion, low leadership satisfaction, and low social support may adversely affect retention. There is a need to understand how these and other factors influence retention in U.S. Navy personnel. We evaluated a broad range of factors influencing job satisfaction and career intentions (proxies of retention) in a large sample of Navy service members.

MATERIALS AND METHODS

Seven hundred and ninety-eight U.S. Navy men and women participated in this study as part of the Naval Unit Behavioral Health Needs Survey (NHRC.2014.0006). Independent variables included personal and unit morale, unit cohesion, affective organizational commitment, social support, behavioral health, sleep, leadership satisfaction, and perceived stress. Dependent variables include job satisfaction and career intentions. Separate multivariate regression models examined the unique and combined associations of independent and demographic variables with each dependent variable, respectively.

RESULTS

Regression models accounted for 48% of variance in job satisfaction and 55% of variance in career intentions, respectively. The most robust predictors of job satisfaction were affective organizational commitment (i.e., one's emotional attachment to, identification with, and involvement in an organization), depressive symptoms, unit cohesion, and perceived stress; primary predictors of career intentions included affective organizational commitment, years of military service, marital status, and race/ethnicity.

CONCLUSION

In this study, we identified diverse predictors of job satisfaction and career intentions of Navy men and women, with overall models accounting for substantial variance in both outcomes. This study informs evidence-based policies, programs, practices, and processes designed to influence job satisfaction, career intentions, and retention in U.S. Navy service members. These study findings also inform the development of a dashboard indicator of retention of U.S. Navy men and women.

Blast exposure interacts with genetic variant 5HTTLPR to predict posttraumatic stress symptoms in military explosives personnel

The first of its kind, this study determined whether blast exposure interacts with genetic variant 5HTTLPR to predict posttraumatic stress (PTS) symptoms in 78 military explosives operators. In all models, blast-exposed 5HTTLPR S carriers registered definitively higher PTS symptoms in comparison to non-exposed S carriers, as well as exposed and non-exposed LL carriers (all p < 0.01). All findings were robust to confounding influences of age and traumatic brain injury diagnosis. Not only is blast exposure prevalent in EOD personnel, but it also interacts with genetic predisposition to predict trauma symptoms in this unique, at-risk military population.

Anabolic hormone profiles in elite military men: Robust associations with age, stress, and fatigue

We recently established stable daily profiles of the anabolic hormones dehydroepiandrosterone (DHEA) and testosterone in 57 elite military men. In this follow-on study, we explored associations of salivary anabolic hormone profiles with demographic (i.e., age, body mass index [BMI]) and biobehavioral health indices (i.e., blood pressure, sleep, perceived stress, fatigue) via correlational models. Next, nuanced patterns were constructed using quartile splits followed by one-way analysis of variance and post hoc subgroup comparisons. Both DHEA (r range: -0.33 to -0.49) and testosterone (r range: -0.19 to -0.41) were inversely associated with age. Quartile comparisons revealed that age-related declines in DHEA were linear, curvilinear, or sigmoidal, depending on the summary parameter of interest. Anabolic hormone profiles did not associate with BMI, blood pressure, or sleep efficiency. Robust linear associations were observed between testosterone and perceived stress (r range: -0.29 to -0.36); concentration-dependent patterns were less discernible. Lower DHEA (r range: -0.22 to -0.30) and testosterone (r range: -0.22 to -0.36) concentrations associated with higher fatigue. Subsequent quartile comparisons suggested a concentration-dependent threshold with respect to evening testosterone. Specifically, those individuals within the lowest quartile (≤68.4pg/mL) endorsed the highest fatigue of the four groups (p=0.01), while the remaining three groups did not differ from each other. This study not only showed that anabolic hormone profiles have distinctive age trajectories, but are also valuable predictors of stress and fatigue in elite military men. This highlights the importance of routine monitoring of anabolic hormone profiles to sustain and optimize health and readiness in chronically stressed populations.

The "yin and yang" of the adrenal and gonadal systems in elite military men

We recently established daily, free-living profiles of the adrenal hormone cortisol, the (primarily adrenal) anabolic precursor dehydroepiandrosterone (DHEA) and the (primarily gonadal) anabolic hormone testosterone in elite military men. A prevailing view is that adrenal and gonadal systems reciprocally modulate each other; however, recent paradigm shifts prompted the characterization of these systems as parallel, cooperative processes (i.e. the "positive coupling" hypothesis). In this study, we tested the positive coupling hypothesis in 57 elite military men by evaluating associations between adrenal and gonadal biomarkers across the day. Salivary DHEA was moderately and positively coupled with salivary cortisol, as was salivary testosterone. Anabolic processes (i.e. salivary DHEA and testosterone) were also positively and reliably coupled across the day. In multivariate models, salivary DHEA and cortisol combined to account for substantial variance in salivary testosterone concentrations across the day, but this was driven almost exclusively by DHEA. This may reflect choreographed adrenal release of DHEA with testicular and/or adrenal release of testosterone, systemic conversion of DHEA to testosterone, or both. DHEA and testosterone modestly and less robustly predicted cortisol concentrations; this was confined to the morning, and testosterone was the primary predictor. Altogether, top-down co-activation of adrenal and gonadal hormone secretion may complement bottom-up counter-regulatory functions to foster anabolic balance and neuronal survival; hence, the "yin and yang" of adrenal and gonadal systems. This may be an adaptive process that is amplified by stress, competition, and/or dominance hierarchy.