Chronic respiratory symptoms following deployment-related occupational and environmental exposures among US veterans.

OBJECTIVES: Characterise inhalational exposures during deployment to Afghanistan and Southwest Asia and associations with postdeployment respiratory symptoms. METHODS: Participants (n=1960) in this cross-sectional study of US Veterans (Veterans Affairs Cooperative Study 'Service and Health Among Deployed Veterans') completed an interviewer-administered questionnaire regarding 32 deployment exposures, grouped a priori into six categories: burn pit smoke; other combustion sources; engine exhaust; mechanical and desert dusts; toxicants; and military job-related vapours gas, dusts or fumes (VGDF). Responses were scored ordinally (0, 1, 2) according to exposure frequency. Factor analysis supported item reduction and category consolidation yielding 28 exposure items in 5 categories. Generalised linear models with a logit link tested associations with symptoms (by respiratory health questionnaire) adjusting for other covariates. OR were scaled per 20-point score increment (normalised maximum=100). RESULTS: The cohort mean age was 40.7 years with a median deployment duration of 11.7 months. Heavy exposures to multiple inhalational exposures were commonly reported, including burn pit smoke (72.7%) and VGDF (72.0%). The prevalence of dyspnoea, chronic bronchitis and wheeze in the past 12 months was 7.3%, 8.2% and 15.6%, respectively. Burn pit smoke exposure was associated with dyspnoea (OR 1.22; 95% CI 1.06 to 1.47) and chronic bronchitis (OR 1.22; 95% CI 1.13 to 1.44). Exposure to VGDF was associated with dyspnoea (OR 1.29; 95% CI 1.14 to 1.58) and wheeze (OR 1.18; 95% CI 1.02 to 1.35). CONCLUSION: Exposures to burn pit smoke and military occupational VGDF during deployment were associated with an increased odds of chronic respiratory symptoms among US Veterans.

Early predictors of chronic posttraumatic stress disorder symptom trajectories in U.S. Army soldiers deployed to the Iraq war zone.

The course of posttraumatic stress disorder (PTSD) symptoms varies among veterans of war zones, but sources of variation in long-term symptom course remain poorly understood. Modeling of symptom growth trajectories facilitates the understanding of predictors of individual outcomes over time. Although growth mixture modeling (GMM) has been applied to military populations, few studies have incorporated both predeployment and follow-up measurements over an extended time. In this prospective study, 1,087 U.S. Army soldiers with varying military occupational specialties and geographic locations were assessed before and after deployment to the Iraq war zone, with long-term follow-up assessment occurring at least 5 years after return from deployment. The primary outcome variable was the PTSD Checklist-Civilian Version summary score. GMM yielded four latent profiles, characterized as primarily asymptomatic (n = 194, 17.8%); postdeployment worsening symptoms (n = 84, 7.7%); mild symptoms (n = 320, 29.4%); and preexisting, with a chronic postdeployment elevation of symptoms (n = 489, 45.0%). Regression models comparing the primarily asymptomatic class to the symptomatic classes revealed that chronic symptom classes were associated with higher degrees of stress exposure, less predeployment social support, military reservist or veteran status at the most recent assessment, and poorer predeployment visual memory, ORs = 0.98-2.90. PTSD symptom course varies considerably over time after military deployment and is associated with potentially modifiable biopsychosocial factors that occur early in its course in addition to exposures and military status.

Health symptom trajectories and neurotoxicant exposures in Gulf War veterans: the Ft. Devens cohort.

BACKGROUND: Thirty years ago, Gulf War (GW) veterans returned home with numerous health symptoms that have been associated with neurotoxicant exposures experienced during deployment. The health effects from these exposures have been termed toxic wounds. Most GW exposure-outcome studies utilize group analyses and thus individual fluctuations in symptoms may have been masked. This study investigates health symptom trajectories in the same veterans over 25 years. METHODS: Veterans were categorized into 5 a priori trajectory groups for each health symptom and Chronic Multisymptom Illness (CMI) clinical case status. Multinomial logistic regression models were used to investigate associations between these trajectories and neurotoxicant exposures. RESULTS: Results indicate that more than 21 Pyridostigmine Bromide (PB) pill exposure was associated with consistent reporting of fatigue, pain, and cognitive/mood symptoms as well as the development of six additional symptoms over time. Chemical weapons exposure was associated with both consistent reporting and development of neurological symptoms over time. Reported exposure to tent heater exhaust was associated with later development of gastrointestinal and pulmonary symptoms. Veterans reporting exposure to more than 21 PB pills were more than 8 times as likely to consistently meet the criteria for CMI over time. CONCLUSION: This study highlights the importance of the continued documentation of the health impacts experienced by GW veterans', their resulting chronic health symptoms, and the importance of exposure-outcome relationships in these veterans now 30 years post-deployment.

Body mass does not reflect the body composition changes in response to similar physical training in young women and men.

INTRODUCTION: U.S. Army Basic Combat Training (BCT) prepares new recruits to meet soldier physical demands. It also serves as a model of physical changes in healthy young nonobese women and men during an intensive 10-week training program without diet restriction. In this prospective observational study, we quantified the changes in lean mass and body fat induced by BCT in a large sample of men and women undergoing the same physical training program. METHODS: Young women (n = 573) and men (n = 1071) meeting Army health and fitness recruitment standards volunteered to provide DXA-derived body composition data at the beginning and end of BCT. RESULTS: During BCT, there was no change in body mass in women and a 1.7-kg loss in men. Relative body fat (%BF) declined by an average of 4.0 ± 2.4 and 3.4 ± 2.8 percentage points (±SD) for women and men, respectively. The greatest predictor of change in %BF during BCT for both sexes was %BF at the beginning of training. Women and men gained an average 2.7 ± 1.6 kg and 1.7 ± 2.0 kg of lean mass during BCT. CONCLUSIONS: Army BCT produced significant effects on body composition despite minimal changes in total body mass. These findings demonstrate the ability of a 10-week sex-integrated physical training program to positively alter body composition profiles of young adults.

Associations Among Increases in Posttraumatic Stress Symptoms, Neurocognitive Performance, and Long-Term Functional Outcomes in U.S. Iraq War Veterans.

Cross-sectional research suggests that posttraumatic stress symptoms (PTSS) among war zone veterans are associated with functional impairment and poor quality of life. Less is known about the long-term functional repercussions of PTSS. This study of Iraq War veterans examined the associations between increases in PTSS and long-term functional outcomes, including the potential contributions of neurocognitive decrements. Service members and veterans (N = 594) completed self-report measures of functioning and PTSS severity before Iraq War deployment and again after their return (M = 9.3 years postdeployment). Some participants (n = 278) also completed neurocognitive testing at both times. Multiple regression analyses with the full sample-adjusted for TBI, demographic characteristics, military variables, and predeployment PTSS and functioning-revealed that increased PTSS severity over time was significantly associated with unemployment, aOR = 1.04, 95% CI [1.03, 1.06]; poorer work performance; and poorer physical, emotional, and cognitive health-related functioning at long-term follow-up, f2 s = 0.37-1.79. Among participants who completed neurocognitive testing, a decline in select neurocognitive measures was associated with poorer functioning; however, neurocognitive decrements did not account for associations between increased PTSS and unemployment, aOR = 1.04, 95% CI [1.02, 1.07], with the size and direction upheld after adding neurocognitive variables, or poorer functional outcomes, with small increases after adding neurocognitive measures to the models, f2 s = 0.03-0.10. War zone veterans experiencing long-term increased PTSS and/or neurocognitive decrements may be at elevated risk for higher-level functional impairment over time, suggesting that early PTSS management may enhance long-term functioning.

A prospective field study of U.S. Army trainees to identify the physiological bases and key factors influencing musculoskeletal injuries: a study protocol.

BACKGROUND: Musculoskeletal injuries (MSKIs) are common in military trainees and present a considerable threat to occupational fitness, deployability, and overall military readiness. Despite the negative effects of MSKIs on military readiness, comprehensive evaluations of the key known and possible risk factors for MSKIs are lacking. The U.S. Army Research Institute of Environmental Medicine (ARIEM) is initiating a large-scale research effort, the ARIEM Reduction in Musculoskeletal Injury (ARMI) Study, to better understand the interrelationships among a wide range of potential MSKI risk factors in U.S. Army trainees in order to identify those risk factors that most contribute to MSKI and may be best targeted for effective mitigation strategies. METHODS: This prospective study aims to enroll approximately 4000 (2000 male and 2000 female) U.S. Army trainees undergoing Basic Combat Training (BCT). Comprehensive in-person assessments will be completed at both the beginning and end of BCT. Participants will be asked to complete surveys of personal background information, medical history, physical activity, sleep behaviors, and personality traits. Physical measurements will be performed to assess anthropometrics, tibial microarchitecture and whole body bone mineral density, muscle cross-sectional area, body composition, and muscle function. Blood sampling will be also be conducted to assess musculoskeletal, genetic, and nutritional biomarkers of risk. In addition, participants will complete weekly surveys during BCT that examine MSKI events, lost training time, and discrete risk factors for injury. Participants' medical records will be tracked for the 2 years following graduation from training to identify MSKI events and related information. Research hypotheses focus on the development of a multivariate prediction model for MSKI. DISCUSSION: Results from this study are expected to inform current understanding of known and potential risk factors for MSKIs that can be incorporated into solutions that optimize Soldier health and enhance military readiness.

Longitudinal Associations among Posttraumatic Stress Disorder Symptoms, Traumatic Brain Injury, and Neurocognitive Functioning in Army Soldiers Deployed to the Iraq War.

OBJECTIVES: Military deployment is associated with increased risk of adverse emotional and cognitive outcomes. Longitudinal associations involving posttraumatic stress disorder (PTSD), relatively mild traumatic brain injury (TBI), and neurocognitive compromise are poorly understood, especially with regard to long-term outcomes, and rigorous research is necessary to better understand the corresponding relationships. The objective of this study was to examine short-term and long-term (>5 years) longitudinal associations among PTSD, neurocognitive performance, and TBI following military deployment. METHODS: In this prospective study, N=315 U.S. Army soldiers were assessed at military installations before (2003-2005) and after (2004-2006) an index deployment to the Iraq War, and again an average of 7.6 years later (2010-2014) as a nationally dispersed cohort of active duty soldiers, reservists, and veterans. Thus, the study design allowed for two measurement intervals over which to examine changes. All assessments included the PTSD Checklist, civilian version, and individually-administered performance-based neurocognitive tests. TBI history was derived from clinical interview. RESULTS: Autoregressive analyses indicated that visual reproduction scores were inversely related to subsequent PTSD symptom severity at subsequent assessments. Conversely, increases in PTSD symptom severity over each measurement interval were associated with poorer verbal and/or visual recall at the end of each interval, and less efficient reaction time at post-deployment. TBI, primarily mild in this sample, was associated with adverse PTSD symptom outcomes at both post-deployment and long-term follow-up. CONCLUSIONS: These results suggest longitudinal relationships among PTSD symptoms, TBI, and neurocognitive decrements may contribute to sustained emotional and neurocognitive symptoms over time. (JINS, 2018, 24, 311-323).

Prospective Examination of Early Associations of Iraq War Zone Deployment, Combat Severity, and Posttraumatic Stress Disorder with New Incident Medical Diagnoses.

War zone deployment and posttraumatic stress disorder (PTSD) have been associated with morbidity and mortality decades later. Less is known about the associations between these variables and the early emergence of medical disorders in war zone veterans. This prospective study of 862 U.S. Army soldiers (n = 569 deployed; n = 293 nondeployed) examined: (a) associations between Iraq War deployment status (deployed vs. nondeployed) and new medical diagnoses that emerged within six months after return from Iraq among all participants; and (b) associations between combat severity and PTSD symptoms, and new postdeployment medical diagnoses that emerged within 12 months after return from Iraq within deployed participants. New medical diagnoses were abstracted from diagnostic codes associated with clinical outpatient visits recorded within the Department of Defense Standard Ambulatory Data Record database. Combat severity was measured with the Combat Experiences module of the Deployment Risk and Resilience Inventory, and postdeployment posttraumatic stress disorder symptom severity was measured using the PTSD Checklist-Civilian. Neither deployment nor combat severity was associated with new medical diagnoses. However, among deployed soldiers, more severe PTSD symptoms were associated with increased risk for a new medical disorder diagnosis; every 10-point increase in PTSD symptoms increased odds of a new diagnosis by nearly 20% (odds ratio = 1.20). Results suggest that PTSD symptoms are associated with early morbidity in Iraq War veterans.

Longitudinal Examination of Posttraumatic Stress Disorder as a Long-Term Outcome of Iraq War Deployment.

The mental health toll of the Iraq and Afghanistan Wars on military veterans has been considerable, yet little is known about the persistence of these adverse outcomes, especially relative to predeployment status. We prospectively examined posttraumatic stress disorder (PTSD) as a long-term consequence of warzone deployment, integrating data collected from 2003-2014. In the Neurocognition Deployment Health Study, we measured PTSD symptoms in US Army soldiers before and shortly after Iraq War deployment. We used the PTSD Checklist-Civilian Version and a structured clinical interview (i.e., Clinician-Administered PTSD Scale) to reassess PTSD in 598 service members and military veterans a median of 7.9 years (interquartile range, 7.2-8.5 years) after an index Iraq deployment. At long-term follow-up, 24.7% (95% confidence interval (CI): 21.5, 28.4) of participants met the case definition for PTSD, which was an absolute increase of 14.2% from the percentage assessed postdeployment (10.5%; 95% CI: 7.8, 13.7) and of 17.3% from the percentage assessed predeployment (7.4%; 95% CI: 5.5, 9.8). These findings highlight that PTSD is an enduring consequence of warzone participation among contemporary military personnel and veterans. The largest increase in PTSD cases occurred between the postdeployment and long-term follow-up assessments, which suggests that adverse stress reactions cannot necessarily be expected to dissipate over time and actually may increase.

Self-Reported Traumatic Brain Injury, Health and Rate of Chronic Multisymptom Illness in Veterans From the 1990-1991 Gulf War.

BACKGROUND: Traumatic brain injury (TBI) was not considered to be common in the 1990-1991 Gulf War (GW). Therefore, the relationship between TBI and chronic health symptoms experienced by GW veterans is unknown. Health symptoms reported by veterans deployed more recently to this region (Operations Enduring and Iraqi Freedom) are similar to those of GW veterans and have been primarily attributed to TBI. OBJECTIVE: To examine the relationships among self-reported TBI, health symptoms, chronic multisymptom illness (CMI), and health-related quality of life among GW veterans. PARTICIPANTS: Participants included 1 274 GW veterans from the Devens Cohort Study, 156 of whom self-reported a history of TBI (12.2% of the sample). DESIGN: Cross-sectional retrospective analysis of existing survey data. MAIN MEASURES: A 52-item health symptom checklist and the RAND 36-Item Health short Form Survey. RESULTS: Self-reported TBI in GW Veterans is related to increased rates of health symptoms, CMI, and poorer health-related quality of life. CONCLUSIONS: Gulf War veterans' self-reported exposure to TBI is related to increased rates of chronic health symptoms and CMI, which interfere with everyday activities of daily living.

Consistency of Recall for Deployment-Related Traumatic Brain Injury.

OBJECTIVE: To examine the temporal consistency of self-reported deployment-related traumatic brain injury (TBI) and its association with posttraumatic stress disorder (PTSD) symptom severity. SETTING: In-person interviews at US Army installations (postdeployment); phone interviews (long-term follow-up). PARTICIPANTS: A total of 378 US Army soldiers and veterans deployed to Iraq; 14.3% (n = 54) reported TBI with loss of consciousness during an index deployment. DESIGN: Participants were evaluated after returning from deployment and again 5 to 9 years later. MAIN MEASURES: Temporal consistency of TBI endorsement based on TBI screening interviews; PTSD Checklist, Civilian Version. RESULTS: The concordance of deployment-related TBI endorsement from the postdeployment to long-term follow-up assessment was moderate (κ = 0.53). Of the 54 participants reporting (predominantly mild) TBI occurring during an index deployment, 32 endorsed TBI inconsistently over time. More severe PTSD symptoms at postdeployment assessment were independently associated with discordant reporting (P = .0004); each 10-point increase in PCL scores increasing odds of discordance by 69% (odds ratio = 1.69; 95% confidence interval, 1.26-2.26). CONCLUSIONS: Deployment-related TBI may not be reported reliably over time, particularly among war-zone veterans with greater PTSD symptoms. Results of screening evaluations for TBI history should be viewed with caution in the context of PTSD symptom history.

Consistency of Reporting for Stressful Life Events Among Nondeployed Soldiers.

OBJECTIVES: Measurement of stress exposure is central to understanding military mental health outcomes. Although temporal stability of combat event reporting has been examined, less is known about the stability of reporting for noncombat events in military samples. Objectives are to examine consistency in reporting stressful life events in nondeployed U.S. Army soldiers and its association with posttraumatic stress disorder (PTSD) symptomatology. METHOD: Examined reporting consistency over approximately 8 months among 466 soldiers. Regression models examined factors associated with decreased, increased, and stable reporting. RESULTS: Stability of the number of events endorsed over time was high. However, item-level agreement was slight to moderate (kappas: .13-.54), with inconsistencies due primarily to decreased reporting. After adjusting for covariates and initial PTSD, second assessment PTSD was associated with increased and stable reporting. CONCLUSIONS: Inconsistent reporting extends beyond combat events to other stressful life events in military personnel and is associated with PTSD.

Prospective examination of cigarette smoking among Iraq-deployed and nondeployed soldiers: prevalence and predictive characteristics.

BACKGROUND: Identifying characteristics that influence smoking behavior among military personnel is critical to protect health and operational functioning. PURPOSE: This study prospectively examined rates of cigarette smoking and predictors of changes in smoking behavior as a function of Iraq deployment. METHODS: One thousand eighty-two US Army soldiers (n = 773 Iraq-deployed; n = 309 nondeployed) completed assessments at two sessions [time 1: April 2003-July 2004; time 2: May 2004-July 2004 (nondeployers); January 2005-September 2006 (deployers)]. RESULTS: Approximately 48 % of participants smoked at both time points, with 6 % initiating smoking and 6 % quitting. Smoking initiation was associated with warzone stress exposure; female gender and high military unit support predicted cessation. Military rank and alcohol use were associated with both smoking initiation and cessation. CONCLUSION: Findings highlight the potential benefits of targeting risk factors for cigarette smoking in comprehensive military health programs aimed at smoking prevention and cessation.

Deployment-related Cigarette Smoking Behaviors and Pulmonary Function Among U.S. Veterans.

INTRODUCTION: The effects of smoking on lung function among post-9/11 Veterans deployed to environments with high levels of ambient particulate matter are incompletely understood. MATERIALS AND METHODS: We analyzed interim data (04/2018-03/2020) from the Veterans Affairs (VA) Cooperative Studies Program #595, "Service and Health Among Deployed Veterans". Veterans with ≥1 land-based deployments enrolled at 1 of 6 regional Veterans Affairs sites completed questionnaires and spirometry. Multivariable linear regression models assessed associations between cigarette smoking (cumulative, deployment-related and non-deployment-related) with pulmonary function. RESULTS: Among 1,836 participants (mean age 40.7 ± 9.6, 88.6% male), 44.8% (n = 822) were ever-smokers (mean age 39.5 ± 9.5; 91.2% male). Among ever-smokers, 86% (n = 710) initiated smoking before deployment, while 11% (n = 90) initiated smoking during deployment(s). Smoking intensity was 50% greater during deployment than other periods (0.75 versus 0.50 packs-per-day; P < .05), and those with multiple deployments (40.4%) were more likely to smoke during deployment relative to those with single deployments (82% versus 74%). Total cumulative pack-years (median [IQR] = 3.8 [1, 10]) was inversely associated with post-bronchodilator FEV1%-predicted (-0.82; [95% CI] = [-1.25, -0.50] %-predicted per 4 pack-years) and FEV1/FVC%-predicted (-0.54; [95% CI] = [-0.78, -0.43] %-predicted per 4 pack-years). Deployment-related pack-years demonstrated similar point estimates of associations with FEV1%-predicted (-0.61; [95% CI] = [-2.28, 1.09]) and FEV1/FVC%-predicted (-1.09; [95% CI] = [-2.52, 0.50]) as non-deployment-related pack-years (-0.83; [95% CI] = [-1.26, -0.50] for FEV1%-predicted; -0.52; [95% CI] = [-0.73, -0.36] for FEV1/FVC%-predicted). CONCLUSIONS: Although cumulative pack-years smoking was modest in this cohort, an inverse association with pulmonary function was detectable. Deployment-related pack-years had a similar association with pulmonary function compared to non-deployment-related pack-years.

Relationships among predeployment risk factors, warzone-threat appraisal, and postdeployment PTSD symptoms.

Previous research indicates a relationship between perceived fear for one's safety (i.e., threat appraisal) and posttraumatic stress disorder (PTSD). This prospective study examined relationships among deployment- and predeployment-related variables, threat appraisal, and postdeployment PTSD symptom severity. Prior to Iraq deployment, 774 U.S. Army soldiers completed self-report measures assessing previous life stressors, deployment history, current (predeployment) PTSD symptoms, deployment preparedness, and unit cohesion. Following deployment, participants completed self-report measures assessing combat intensity, deployment threat appraisal, and current (postdeployment) PTSD symptoms. Structural equation modeling revealed that predeployment PTSD symptom severity, prior warzone deployment, unit cohesion, and preparedness were each independently associated with deployment threat appraisal, even after taking into account combat intensity. Deployment threat appraisal was associated with postdeployment PTSD severity. Results indicated that predeployment PTSD symptom severity, history of warzone deployment, and preparedness-risk factors previously thought to influence PTSD outcomes directly-were either partially or fully mediated by threat appraisal. The model explained 15% of the variance in deployment threat appraisal and 50% of the variance in postdeployment PTSD severity. Helping service members cope with exposure to extreme stress during deployment by modifying certain prewar risk factors may facilitate reduction of PTSD symptoms following deployment.

Individual-level permethrin exposure biomarkers in U.S. army soldiers: comparison of two treatment formulations for military uniforms.

BACKGROUND: Evidence suggests that wearing permethrin-treated military uniforms is not associated with current adverse health conditions. However, exposure through this route results in permethrin biomarker concentrations considerably higher than those in the U.S. POPULATION: The U.S. Army is exploring different methods of uniform treatment that reduce exposure while maintaining effective protection from insect vector-borne diseases. OBJECTIVE: To compare permethrin exposure when wearing two types of permethrin-treated military uniforms. METHODS: Eight male soldiers participated in a 32-day crossover design study to compare permethrin exposure when wearing the current Army uniform (CurrU) and a uniform with a new applied fabric treatment (NewU). Each soldier wore the uniforms for designated 8 h/day time periods over 3 consecutive days separated by a 'wash-out' week of no exposure. Permethrin exposure was assessed from the urinary concentrations of 3-phenoxybenzoic acid (3-PBA) and of the sum of cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (∑DCCA). Estimated dose was determined based on ∑DCCA concentrations. RESULTS: Permethrin exposure biomarkers were 21% (3-PBA, p = 0.025) and 35% (∑DCCA, p < 0.001) lower when wearing the NewU compared to the CurrU; the dose was 33% lower (p = 0.05). SIGNIFICANCE: Findings suggest the new treatment reduces human permethrin exposure biomarkers resulting from wearing-treated military uniforms.

Changes in Distal Tibial Microarchitecture During Eight Weeks of U.S. Army Basic Combat Training Differ by Sex and Race.

Basic combat training (BCT) is a physically rigorous period at the beginning of a soldier's career that induces bone formation in the tibia. Race and sex are determinants of bone properties in young adults but their influences on changes in bone microarchitecture during BCT are unknown. The purpose of this work was to determine the influence of sex and race on changes in bone microarchitecture during BCT. Bone microarchitecture was assessed at the distal tibia via high-resolution peripheral quantitative computed tomography at the beginning and end of 8 weeks of BCT in a multiracial cohort of trainees (552 female, 1053 male; mean ± standard deviation [SD] age = 20.7 ± 3.7 years) of which 25.4% self-identified as black, 19.5% as race other than black or white (other races combined), and 55.1% as white. We used linear regression models to determine whether changes in bone microarchitecture due to BCT differed by race or sex, after adjusting for age, height, weight, physical activity, and tobacco use. We found that trabecular bone density (Tb.BMD), thickness (Tb.Th), and volume (Tb.BV/TV), as well as cortical BMD (Ct.BMD) and thickness (Ct.Th) increased following BCT in both sexes and across racial groups (+0.32% to +1.87%, all p < 0.01). Compared to males, females had greater increases in Tb.BMD (+1.87% versus +1.40%; p = 0.01) and Tb.Th (+0.87% versus +0.58%; p = 0.02), but smaller increases in Ct.BMD (+0.35% versus +0.61%; p < 0.01). Compared to black trainees, white trainees had greater increases in Tb.Th (+0.82% versus +0.61%; p = 0.03). Other races combined and white trainees had greater increases in Ct.BMD than black trainees (+0.56% and + 0.55% versus +0.32%; both p ≤ 0.01). Changes in distal tibial microarchitecture, consistent with adaptive bone formation, occur in trainees of all races and sexes, with modest differences by sex and race. Published 2023. This article is a U.S. Government work and is in the public domain in the USA. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Neuropsychological outcomes of mild traumatic brain injury, post-traumatic stress disorder and depression in Iraq-deployed US Army soldiers.

BACKGROUND: Traumatic brain injury (TBI) is a concern of contemporary military deployments. Whether milder TBI leads to enduring impairment remains controversial. AIMS: To determine the influence of deployment TBI, and post-traumatic stress disorder (PTSD) and depression symptoms on neuropsychological and functional outcomes. METHOD: A sample of 760 US Army soldiers were assessed pre- and post-deployment. Outcomes included neuropsychological performances and subjective functional impairment. RESULTS: In total, 9% of the participants reported (predominantly mild) TBI with loss of consciousness between pre- and post-deployment. At post-deployment, 17.6% of individuals with TBI screened positive for PTSD and 31.3% screened positive for depression. Before and after adjustment for psychiatric symptoms, TBI was significantly associated only with functional impairment. Both PTSD and depression symptoms adjusted for TBI were significantly associated with several neuropsychological performance deficits and functional impairment. CONCLUSIONS: Milder TBI reported by deployed service members typically has limited lasting neuropsychological consequences; PTSD and depression are associated with more enduring cognitive compromise.

Characterization of inhalation exposure to jet fuel among U.S. Air Force personnel.

BACKGROUND: Jet propulsion fuel-8 (JP-8) is the primary jet fuel used by the US military, collectively consuming ~2.5 billion gallons annually. Previous reports suggest that JP-8 is potentially toxic to the immune, respiratory, and nervous systems. The objectives of this study were to evaluate inhalation exposure to JP-8 constituents among active duty United States Air Force (USAF) personnel while performing job-related tasks, identify significant predictors of inhalation exposure to JP-8, and evaluate the extent to which surrogate exposure classifications were predictive of measured JP-8 exposures. METHODS: Seventy-three full-time USAF personnel from three different air force bases were monitored during four consecutive workdays where personal air samples were collected and analyzed for benzene, ethylbenzene, toluene, xylenes, total hydrocarbons (THC), and naphthalene. The participants were categorized a priori into high- and low-exposure groups, based on their exposure to JP-8 during their typical workday. Additional JP-8 exposure categories included job title groups and self-reported exposure to JP-8. Linear mixed-effects models were used to evaluate predictors of personal air concentrations. RESULTS: The concentrations of THC in air were significantly different between a priori exposure groups (2.6 mg m(-3) in high group versus 0.5 mg m(-3) in low, P < 0.0001), with similar differences observed for other analytes in air. Naphthalene was strongly correlated with THC (r = 0.82, P < 0.0001) and both were positively correlated with the relative humidity of the work environment. Exposures to THC and naphthalene varied significantly by job categories based on USAF specialty codes and were highest among personnel working in fuel distribution/maintenance, though self-reported exposure to JP-8 was an even stronger predictor of measured exposure in models that explained 72% (THC) and 67% (naphthalene) of between-worker variability. In fact, both self-report JP-8 exposure and a priori exposure groups explained more between-worker variability than job categories. CONCLUSIONS: Personal exposure to JP-8 varied by job and was positively associated with the relative humidity. However, self-reported exposure to JP-8 was an even stronger predictor of measured exposure than job title categories, suggesting that self-reported JP-8 exposure is a valid surrogate metric of exposure when personal air measurements are not available.

Physical Injuries, Treatment-Seeking, and Perceived Barriers to Treatment in U.S. Army Drill Sergeants.

INTRODUCTION: Drill sergeants work under mentally and physically challenging conditions. The current study examined self-reported rates of physical injuries in drill sergeants; rates of treatment-seeking for injuries; perceived barriers toward treatment-seeking; and associated demographic and environmental factors. MATERIALS AND METHODS: Drill sergeants from across all Army basic training locations completed self-report surveys from September to November of 2018. In total, 726 drill sergeants were included in analyses. Drill sergeants indicated whether they had acquired an injury during their time in the drill sergeant role and whether they had sought treatment for all such injuries. Furthermore, drill sergeants rated their agreement with a number of possible perceived barriers to treatment-seeking for physical injuries. Regression models examining each phenomenon included hours of sleep obtained per day; general- and health-specific leadership behaviors of the company command teams; unit cohesion; time as a drill sergeant; duty location; gender; military operational specialty; years in the military; previous combat deployments; and route of assignment. The study was approved by the Walter Reed Army Institute of Research Institutional Review Board. RESULTS: In total, 38% of respondents reported acquiring an injury during their time as drill sergeants. Of those who had acquired an injury, 61% reported seeking medical help for all injuries acquired. Injuries were more likely in females (49%) than in males (34%) and less likely in drill sergeants reporting at least 6 hours of sleep (27%) versus those reporting 5 hours (40%) and 4 hours or less (43%). Reported comparisons were significant after controlling for demographic and environmental variables in regression models. The most strongly endorsed perceived barriers to treatment-seeking were "Seeking help would place too much burden on the other drill sergeants" (69%) and "Seeking help would interfere with my ability to train the recruits" (60%). Both of these perceived barriers were significantly associated with reduced treatment-seeking in injured drill sergeants, after controlling for demographic and environmental variables. CONCLUSIONS: This study is the first to examine injury occurrence, treatment-seeking, and perceived barriers to treatment-seeking in U.S. Army drill sergeants. Building on previous studies that showed the negative effects of sleep deprivation on the safety and behavioral health of drill sergeants, the current study gives further evidence of the negative effects of such sleep deprivation, this time in the domain of physical injuries. The results suggest that pursuing strategies that allow for healthier sleep duration may contribute to injury reduction.