Impact of repeated blast exposure on active-duty United States Special Operations Forces.

United States (US) Special Operations Forces (SOF) are frequently exposed to explosive blasts in training and combat, but the effects of repeated blast exposure (RBE) on SOF brain health are incompletely understood. Furthermore, there is no diagnostic test to detect brain injury from RBE. As a result, SOF personnel may experience cognitive, physical, and psychological symptoms for which the cause is never identified, and they may return to training or combat during a period of brain vulnerability. In 30 active-duty US SOF, we assessed the relationship between cumulative blast exposure and cognitive performance, psychological health, physical symptoms, blood proteomics, and neuroimaging measures (Connectome structural and diffusion MRI, 7 Tesla functional MRI, [11C]PBR28 translocator protein [TSPO] positron emission tomography [PET]-MRI, and [18F]MK6240 tau PET-MRI), adjusting for age, combat exposure, and blunt head trauma. Higher blast exposure was associated with increased cortical thickness in the left rostral anterior cingulate cortex (rACC), a finding that remained significant after multiple comparison correction. In uncorrected analyses, higher blast exposure was associated with worse health-related quality of life, decreased functional connectivity in the executive control network, decreased TSPO signal in the right rACC, and increased cortical thickness in the right rACC, right insula, and right medial orbitofrontal cortex-nodes of the executive control, salience, and default mode networks. These observations suggest that the rACC may be susceptible to blast overpressure and that a multimodal, network-based diagnostic approach has the potential to detect brain injury associated with RBE in active-duty SOF.

Estimating conflict losses and reporting biases.

Determining the number of casualties and fatalities suffered in militarized conflicts is important for conflict measurement, forecasting, and accountability. However, given the nature of conflict, reliable statistics on casualties are rare. Countries or political actors involved in conflicts have incentives to hide or manipulate these numbers, while third parties might not have access to reliable information. For example, in the ongoing militarized conflict between Russia and Ukraine, estimates of the magnitude of losses vary wildly, sometimes across orders of magnitude. In this paper, we offer an approach for measuring casualties and fatalities given multiple reporting sources and, at the same time, accounting for the biases of those sources. We construct a dataset of 4,609 reports of military and civilian losses by both sides. We then develop a statistical model to better estimate losses for both sides given these reports. Our model accounts for different kinds of reporting biases, structural correlations between loss types, and integrates loss reports at different temporal scales. Our daily and cumulative estimates provide evidence that Russia has lost more personnel than has Ukraine and also likely suffers from a higher fatality to casualty ratio. We find that both sides likely overestimate the personnel losses suffered by their opponent and that Russian sources underestimate their own losses of personnel.

Chronic Traumatic Encephalopathy in the Brains of Military Personnel.

BACKGROUND: Persistent neuropsychiatric sequelae may develop in military personnel who are exposed to combat; such sequelae have been attributed in some cases to chronic traumatic encephalopathy (CTE). Only limited data regarding CTE in the brains of military service members are available. METHODS: We performed neuropathological examinations for the presence of CTE in 225 consecutive brains from a brain bank dedicated to the study of deceased service members. In addition, we reviewed information obtained retrospectively regarding the decedents' histories of blast exposure, contact sports, other types of traumatic brain injury (TBI), and neuropsychiatric disorders. RESULTS: Neuropathological findings of CTE were present in 10 of the 225 brains (4.4%) we examined; half the CTE cases had only a single pathognomonic lesion. Of the 45 brains from decedents who had a history of blast exposure, 3 had CTE, as compared with 7 of 180 brains from those without a history of blast exposure (relative risk, 1.71; 95% confidence interval [CI], 0.46 to 6.37); 3 of 21 brains from decedents with TBI from an injury during military service caused by the head striking a physical object without associated blast exposure (military impact TBI) had CTE, as compared with 7 of 204 without this exposure (relative risk, 4.16; 95% CI, 1.16 to 14.91). All brains with CTE were from decedents who had participated in contact sports; 10 of 60 contact-sports participants had CTE, as compared with 0 of 165 who had not participated in contact sports (point estimate of relative risk not computable; 95% CI, 6.16 to infinity). CTE was present in 8 of 44 brains from decedents with non-sports-related TBI in civilian life, as compared with 2 of 181 brains from those without such exposure in civilian life (relative risk, 16.45; 95% CI, 3.62 to 74.79). CONCLUSIONS: Evidence of CTE was infrequently found in a series of brains from military personnel and was usually reflected by minimal neuropathologic changes. Risk ratios for CTE were numerically higher among decedents who had contact-sports exposure and other exposures to TBI in civilian life than among those who had blast exposure or other military TBI, but the small number of CTE cases and wide confidence intervals preclude causal conclusions. (Funded by the Department of Defense-Uniformed Services University Brain Tissue Repository and Neuropathology Program and the Henry M. Jackson Foundation for the Advancement of Military Medicine.).

Reconstructing biblical military campaigns using geomagnetic field data.

The Hebrew Bible and other ancient Near Eastern texts describe Egyptian, Aramean, Assyrian, and Babylonian military campaigns to the Southern Levant during the 10th to sixth centuries BCE. Indeed, many destruction layers dated to this period have been unearthed in archaeological excavations. Several of these layers are securely linked to specific campaigns and are widely accepted as chronological anchors. However, the dating of many other destruction layers is often debated, challenging the ability to accurately reconstruct the different military campaigns and raising questions regarding the historicity of the biblical narrative. Here, we present a synchronization of the historically dated chronological anchors and other destruction layers and artifacts using the direction and/or intensity of the ancient geomagnetic field recorded in mud bricks from 20 burnt destruction layers and in two ceramic assemblages. During the period in question, the geomagnetic field in this region was extremely anomalous with rapid changes and high-intensity values, including spikes of more than twice the intensity of today's field. The data are useful in the effort to pinpoint these short-term variations on the timescale, and they resolve chronological debates regarding the campaigns against the kingdoms of Israel and Judah, the relationship between the two kingdoms, and their administrations.

The diverse genetic origins of a Classical period Greek army.

Trade and colonization caused an unprecedented increase in Mediterranean human mobility in the first millennium BCE. Often seen as a dividing force, warfare is in fact another catalyst of culture contact. We provide insight into the demographic dynamics of ancient warfare by reporting genome-wide data from fifth-century soldiers who fought for the army of the Greek Sicilian colony of Himera, along with representatives of the civilian population, nearby indigenous settlements, and 96 present-day individuals from Italy and Greece. Unlike the rest of the sample, many soldiers had ancestral origins in northern Europe, the Steppe, and the Caucasus. Integrating genetic, archaeological, isotopic, and historical data, these results illustrate the significant role mercenaries played in ancient Greek armies and highlight how participation in war contributed to continental-scale human mobility in the Classical world.

Changes in the Seroprevalence of Tick-Borne Rickettsia and Ehrlichia Among Soldiers-Fort Liberty, North Carolina, 1991-2019.

We obtained samples from the Department of Defense Serum Repository from soldiers who were stationed at Fort Liberty, North Carolina, between 1991 and 2019 to assess temporal trends in tick-borne rickettsiosis and ehrlichiosis. Serological evidence of infection was common, with nearly 1 in 5 (18.9%) demonstrating antibodies. We observed significant decreases in Rickettsia seroprevalence (adjusted odds ratio [aOR], 0.42 [95% CI, .27-.65], P = .0001) while over the same period Ehrlichia seroprevalence, albeit less common, nearly doubled (aOR, 3.61 [95% CI, 1.10-13.99], P = .048). The increase in Ehrlichia seroprevalence likely reflects increased transmission resulting from the expanding geographic range of the lone star tick.

Informing the Need for a SARS-CoV-2 Booster Based on the Immune Responses Among Young Healthy Adults to Variants Circulating in Late 2023.

BACKGROUND: COVID-19 remains a global public health challenge due to new immune-evasive SARS-CoV-2 variants and heterogeneous immunity. METHODS: In this cross-sectional study, we evaluated the adaptive immune responses in US active duty personnel who completed a COVID-19 primary vaccine series and had heterogenous SARS-CoV-2 vaccination and infection histories to 3 previously dominant variants (ancestral, Delta, BA.5) and 3 circulating variants (XBB.1.5, EG.5, and BA.2.86) in late 2023. Analyses were based on the most recent exposure in terms of timing (within or beyond 12 months) and type (vaccine or infection). RESULTS: Significant reduction was observed in binding antibodies, neutralization antibodies, memory B cells, and CD8+ T cells against circulating variants when compared with previous variants. The reduction in antibody response was more pronounced in those whose most recent exposure was >12 months from enrollment. In contrast, the CD4+ T-cell response was largely consistent across all tested variants. The type of most recent exposure was not a significant factor in determining the magnitude of current immune responses. CONCLUSIONS: Administration of the XBB.1.5-based booster is likely to enhance cross-reactive humoral responses against SARS-CoV-2 circulating lineages. Ongoing surveillance of immune responses to emerging variants is needed for informing vaccine composition and timing.

Comparative analysis of circulating metabolomic profiles identifies shared metabolic alterations across distinct multistressor military training exercises.

Military training provides insight into metabolic responses under unique physiological demands that can be comprehensively characterized by global metabolomic profiling to identify potential strategies for improving performance. This study identified shared changes in metabolomic profiles across three distinct military training exercises, varying in magnitude and type of stress. Blood samples collected before and after three real or simulated military training exercises were analyzed using the same untargeted metabolomic profiling platform. Exercises included a 2-wk survival training course (ST, n = 36), a 4-day cross-country ski march arctic training (AT, n = 24), and a 28-day controlled diet- and exercise-induced energy deficit (CED, n = 26). Log2-fold changes of greater than ±1 in 191, 121, and 64 metabolites were identified in the ST, AT, and CED datasets, respectively. Most metabolite changes were within the lipid (57-63%) and amino acid metabolism (18-19%) pathways and changes in 87 were shared across studies. The largest and most consistent increases in shared metabolites were found in the acylcarnitine, fatty acid, ketone, and glutathione metabolism pathways, whereas the largest decreases were in the diacylglycerol and urea cycle metabolism pathways. Multiple shared metabolites were consistently correlated with biomarkers of inflammation, tissue damage, and anabolic hormones across studies. These three studies of real and simulated military training revealed overlapping alterations in metabolomic profiles despite differences in environment and the stressors involved. Consistent changes in metabolites related to lipid metabolism, ketogenesis, and oxidative stress suggest a potential common metabolomic signature associated with inflammation, tissue damage, and suppression of anabolic signaling that may characterize the unique physiological demands of military training.NEW & NOTEWORTHY The extent to which metabolomic responses are shared across diverse military training environments is unknown. Global metabolomic profiling across three distinct military training exercises identified shared metabolic responses with the largest changes observed for metabolites related to fatty acids, acylcarnitines, ketone metabolism, and oxidative stress. These changes also correlated with alterations in markers of tissue damage, inflammation, and anabolic signaling and comprise a potential common metabolomic signature underlying the unique physiological demands of military training.

Impact of SARS-CoV-2 Arrival Surveillance Screening by Nucleic Acid Amplification Versus Rapid Antigen Detection on Subsequent COVID-19 Infections in Military Trainees.

BACKGROUND: For persons entering congregate settings, optimal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) arrival surveillance screening method, nucleic acid amplification test (NAAT) versus rapid antigen detection test (RADT), is debated. To aid this, we sought to determine the risk of secondary symptomatic coronavirus disease 19 (COVID-19) among military trainees with negative arrival NAAT or RADT screening. METHODS: Individuals who arrived for US Air Force basic military training from 1 January-31 August 2021 were placed into training groups and screened for SARS-CoV-2 via NAAT or RADT. Secondary symptomatic COVID-19 cases within 2 weeks of training were then measured. A case cluster was defined as ≥5 individual symptomatic COVID-19 cases. RESULTS: 406 (1.6%) of 24 601 trainees screened positive upon arrival. The rate of positive screen was greater for those tested with NAAT versus RADT (2.5% vs 0.4%; RR: 5.4; 95% CI: 4.0-7.3; P < .001). The proportion of training groups with ≥1 positive individual screen was greater in groups screened via NAAT (57.5% vs 10.8%; RR: 5.31; 95% CI: 3.65-7.72; P < .001). However, NAAT versus RADT screening was not associated with a difference in number of training groups to develop a secondary symptomatic case (20.3% vs 22.5%; RR: .9; 95% CI: .66-1.23; P = .53) or case cluster of COVID-19 (4% vs 6.6%; RR: .61; 95% CI: .3-1.22; P = .16). CONCLUSIONS: NAAT versus RADT arrival surveillance screening method impacted individual transmission of COVID-19 but had no effect on number of training groups developing a secondary symptomatic case or case cluster. This study provides consideration for RADT arrival screening in congregate settings.

Influence of spatial orientation training in a centrifuge on the ability of fighter pilots to assess the bank angle during flight without visual references.

Without visual references, nonpilots exposed to coordinated flight turns underestimate the bank angle, because of discordant information of the roll-angular displacement from the otoliths, consistently signaling vertical position, versus the semicircular canals, enabling detection of the displacement. Pilots may also use their ability to perceive the G load and knowledge of the relation between load and angle to assess the bank angle. Our aim was to investigate whether the perception of bank angle can be improved by spatial orientation training in a centrifuge. Sixteen pilots/pilot students assessed their roll tilt, in complete darkness, during both real coordinated flight turns and gondola centrifugation, at roll tilts of 30° and 60°. The experiments were repeated after a 3-wk period, during which eight of the subjects performed nine training sessions in the centrifuge, comprising feedback on roll angle vs. G load, and on indicating requested angles. Before training, the subjects perceived in the aircraft and centrifuge, respectively: 37 (17)°, 38 (14)° during 60° turns and 19 (12)°, 20 (10)° during 30° turns. Training improved the perception of angle during the 60° [to 60 (7)°, 55 (10)°; P ≤ 0.04] but not the 30° [21 (10)°, 15 (9)°; P ≥ 0.30] turns; the improvement disappeared within 2 yr after training. Angle assessments did not change in the untrained group. The results suggest that it is possible to, in a centrifuge, train a pilot's ability to perceive large but not discrete-to-moderate roll-angular displacements. The transient training effect is attributable to improved capacity to perceive and translate G load into roll angle and/or to increased reliance on semicircular canal signals.NEW & NOTEWORTHY Spatial disorientation is a major problem in aviation. When performing coordinated flight turns without external visual cues (e.g., flying in clouds or darkness), the pilot underestimates the aircraft bank angle because the vestibular system provides unreliable information of roll tilt. The present study demonstrates that it is possible to, in a long-arm centrifuge, train a pilot's ability to perceive large but not discrete-to-moderate roll-angular displacements.

Cancer incidence in the US military: An updated analysis.

BACKGROUND: Military and general populations differ in factors related to cancer occurrence and diagnosis. This study compared incidence of colorectal, lung, prostate, testicular, breast, and cervical cancers between the US military and general US populations. METHODS: Data from the US Department of Defense's Automated Central Tumor Registry (ACTUR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program were analyzed. Persons in ACTUR were active-duty members 20-59 years old during 1990-013. The same criteria applied to persons in SEER. Age-adjusted incidence rates, incidence rate ratios, and 95% confidence intervals were calculated by sex, race, age, and cancer stage. Temporal trends were analyzed. RESULTS: ACTUR had higher rates of prostate and breast cancers, particularly in 40- to 59-year-olds. Further analyses by tumor stage showed this was primarily confined to localized stage. Incidence rates of colorectal, lung, testicular, and cervical cancers were significantly lower in ACTUR than in SEER, primarily for regional and distant tumors in men. Temporal incidence trends were generally similar overall and by stage between the populations, although distant colorectal cancer incidence tended to decrease starting in 2006 in ACTUR whereas it increased during the same period in SEER. CONCLUSION: Higher rates of breast and prostate cancers in servicemembers 40-59 years of age than in the general population may result from greater cancer screening utilization or cumulative military exposures. Lower incidence of other cancers in servicemembers may be associated with better health status.

The Golden Hour of Casualty Care: Rapid Handoff to Surgical Team is Associated With Improved Survival in War-injured US Service Members.

OBJECTIVE: To examine time from injury to initiation of surgical care and association with survival in US military casualties. BACKGROUND: Although the advantage of trauma care within the "golden hour" after an injury is generally accepted, evidence is scarce. METHODS: This retrospective, population-based cohort study included US military casualties injured in Afghanistan and Iraq, January 2007 to December 2015, alive at initial request for evacuation with maximum abbreviated injury scale scores ≥2 and documented 30-day survival status after injury. Interventions: (1) handoff alive to the surgical team, and (2) initiation of first surgery were analyzed as time-dependent covariates (elapsed time from injury) using sequential Cox proportional hazards regression to assess how intervention timing might affect mortality. Covariates included age, injury year, and injury severity. RESULTS: Among 5269 patients (median age, 24 years; 97% males; and 68% battle-injured), 728 died within 30 days of injury, 68% within 1 hour, and 90% within 4 hours. Only handoffs within 1 hour of injury and the resultant timely initiation of emergency surgery (adjusted also for prior advanced resuscitative interventions) were significantly associated with reduced 24-hour mortality compared with more delayed surgical care (adjusted hazard ratios: 0.34; 95% CI: 0.14-0.82; P = 0.02; and 0.40; 95% CI: 0.20-0.81; P = 0.01, respectively). In-hospital waits for surgery (mean: 1.1 hours; 95% CI; 1.0-1.2) scarcely contributed ( P = 0.67). CONCLUSIONS: Rapid handoff to the surgical team within 1 hour of injury may reduce mortality by 66% in US military casualties. In the subgroup of casualties with indications for emergency surgery, rapid handoff with timely surgical intervention may reduce mortality by 60%. To inform future research and trauma system planning, findings are pivotal.

The military gear microbiome: risk factors surrounding the warfighter.

Combat extremity wounds are highly susceptible to contamination from surrounding environmental material. This bioburden could be partially transferred from materials in immediate proximity to the wound, including fragments of the uniform and gear. However, the assessment of the microbial bioburden present on military gear during operational conditions of deployment or training is relatively unexplored. Opportunistic pathogens that can survive on gear represent risk factors for infection following injury, especially following combat blasts, where fibers and other materials are embedded in wounded tissue. We utilized 16S rRNA sequencing to assess the microbiome composition of different military gear types (boot, trouser, coat, and canteen) from two operational environments (training in Hawai'i and deployed in Indonesia) across time (days 0 and 14). We found that microbiome diversity, stability, and composition were dependent on gear type, training location, and sampling timepoint. At day 14, species diversity was significantly higher in Hawai'i samples compared to Indonesia samples for boot, coat, and trouser swabs. In addition, we observed the presence of potential microbial risk factors, as opportunistic pathogenic species, such as Acinetobacter, Pseudomonas, and Staphylococcus, were found to be present in all sample types and in both study sites. These study outcomes will be used to guide the design of antimicrobial materials and uniforms and for infection control efforts following combat blasts and other injuries, thereby improving treatment guidance during military training and deployment.IMPORTANCECombat extremity wounds are vulnerable to contamination from environments of proximity to the warfighter, leading to potential detrimental outcomes such as infection and delayed wound healing. Therefore, microbial surveillance of such environments is necessary to aid the advancement of military safety and preparedness through clinical diagnostics, treatment protocols, and uniform material design.

High Uptake of Respiratory Syncitial Virus Prevention for Neonates in a Military Treatment Facility.

We investigated the uptake of nirsevimab for infants and the bivalent respiratory syncytial virus prefusion F (RSVPreF) vaccine for pregnant persons as measures for RSV prevention during an infant's birth hospitalization in a military treatment facility. We found >85% uptake between October 2023 to February 2024. These data may aid health systems plan for future RSV seasons.

Racial-Ethnic Comparison of Treatment for Papillary Thyroid Cancer in the Military Health System.

PURPOSE: We aimed to compare Asian or Pacific Islander, Black, Hispanic, and non-Hispanic White patients in treatment for papillary thyroid cancer (PTC) in the equal access Military Health System to better understand racial-ethnic cancer health disparities observed in the United States. METHODS: We used the MilCanEpi database to identify a cohort of men and women aged 18 or older who were diagnosed with PTC between 1998 and 2014. Low- or high-risk status was assigned using tumor size and lymph node involvement. Treatment with surgery (e.g., thyroidectomy) overall and treatment by risk status [active surveillance (low-risk) or adjuvant radioactive iodine (RAI) (high-risk)] was compared between racial-ethnic groups using multivariable logistic regression and expressed as adjusted odds ratios (AOR) with 95% confidence intervals (CIs). RESULTS: The study included 598 Asian, 553 Black, 340 Hispanic, and 2958 non-Hispanic White patients with PTC. Asian (AOR = 1.21, 95% CI 0.98, 1.49), Black (AOR = 1.07, 95% CI 0.87, 1.32), and Hispanic (AOR = 0.92, 95% CI 0.71, 1.19) patients were as likely as White patients to receive surgery. By risk status, there were no significant racial-ethnic differences in receipt of active surveillance or thyroidectomy for low-risk PTC or in thyroidectomy or total thyroidectomy with adjuvant RAI for high-risk PTC. CONCLUSIONS: In the Military Health System, where patients have equal access to care, there were no overall racial-ethnic differences in surgical treatment for PTC. As American Thyroid Association guidelines evolve to include more conservative treatment, further research is warranted to understand potential disparities in active surveillance and surgical management in U.S. healthcare settings.

Prediction of various insulin resistance indices for the risk of hypertension among military young adults: the CHIEF cohort study, 2014-2020.

BACKGROUND: Non-insulin-based insulin resistance (NI-IR) indices have been reported to have an association with prevalent hypertension, however, no cohort studies to date have compared their prediction of hypertension among young adults. METHODS: A total of 2,448 military men and women, aged 18-39 years, without baseline hypertension in Taiwan were followed for incident hypertension events from 2014 until the end of 2020. All subjects underwent annual health examinations including measurements of blood pressure (BP) in mmHg. Systolic BP (SBP) 130-139/diastolic BP (DBP) < 80, SBP < 130/DBP 80-89, and SBP 130-139/DBP 80-89 were respectively defined as stage I isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH) and combined hypertension (CH). The cut-off levels of stage II hypertension for SBP and DBP were 140-159 and 90-99, respectively. Four NI-IR indices included the ratio of serum triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C), TyG index defined as ln[TG* fasting glucose (FG)/2], Metabolic Score for IR (METS-IR) defined as ln[(2* FG) + TG)* body mass index (BMI)/(ln(HDL-C))], and ZJU index defined as BMI + FG + TG + 3* alanine transaminase/aspartate transaminase (+ 2 if female). Multivariable Cox regression analysis was performed with adjustments for baseline age, sex, body mass index, BP, substance use, family history for early onset cardiovascular diseases or hypertension, low-density lipoprotein cholesterol, kidney function, serum uric acid and physical activity to determine the associations. RESULTS: During a median follow-up of 6.0 years, there were 920 hypertension events (37.6%). Greater TyG, TG/HDL-C and METS-IR indices were associated with a higher risk of stage I IDH (hazard ratios (HRs) and 95% confidence intervals: 1.376 (1.123-1.687), 1.082 (1.039-1.127) and 3.455 (1.921-6.214), respectively), whereas only greater ZJU index was associated with a higher risk of stage II IDH [HRs: 1.011 (1.001-1.021)]. In addition, greater ZJU index was associated with a higher risk of stage II ISH [HR: 1.013 (1.003-1.023)], and greater TyG index was associated with a higher risk of stage II CH [HR: 2.821 (1.244-6.395)]. CONCLUSION: Insulin resistance assessed by various NI-IR indices was associated with a higher risk of hypertension in young adults, while the assessment ability for specific hypertension category may differ by NI-IR indices.

Variation in Time-to-Gender-Affirming Hormone Therapy in US Active Duty Service Members.

BACKGROUND: Beginning in July 2016, transgender service members in the US military were allowed to receive gender-affirming medical care, if so desired. OBJECTIVE: This study aimed to evaluate variation in time-to-hormone therapy initiation in active duty Service members after the receipt of a diagnosis indicative of gender dysphoria in the Military Health System. RESEARCH DESIGN: This retrospective cohort study included data from those enrolled in TRICARE Prime between July 2016 and December 2021 and extracted from the Military Health System Data Repository. PARTICIPANTS: A population-based sample of US Service members who had an encounter with a relevant International Classification of Diseases 9/10 diagnosis code. MEASURES: Time-to-gender-affirming hormone initiation after diagnosis receipt. RESULTS: A total of 2439 Service members were included (M age 24 y; 62% white, 16% Black; 12% Latine; 65% Junior Enlisted; 37% Army, 29% Navy, 25% Air Force, 7% Marine Corps; 46% first recorded administrative assigned gender marker female). Overall, 41% and 52% initiated gender-affirming hormone therapy within 1 and 3 years of diagnosis, respectively. In the generalized additive model, time-to-gender-affirming hormone initiation was longer for Service members with a first administrative assigned gender marker of male relative to female ( P <0.001), and Asian and Pacific Islander ( P =0.02) and Black ( P =0.047) relative to white Service members. In time-varying interactions, junior enlisted members had longer time-to-initiation, relative to senior enlisted members and junior officers, until about 2-years postinitial diagnosis. CONCLUSION: The significant variation and documented inequities indicate that institutional data-driven policy modifications are needed to ensure timely access for those desiring care.

Metabolic flexibility associated with flight time among combat pilots of the Brazilian air force.

INTRODUCTION: Fighter pilots must support the effects of many stressors, including physical and psychological exertion, circadian disturbance, jet lag, and environmental stress. Despite the rigorous selection of military pilots, those factors predispose to failures in physiological compensatory mechanisms and metabolic flexibility. OBJECTIVES: We compared through NMR-based metabolomics the metabolic profile of Brazilian F5 fighter pilots with different flight experiences vs. the control group of non-pilots. We hypothesized that combat pilots have metabolic flexibility associated with combat flight time. METHODS: We evaluated for the first time 34 Brazilian fighter pilots from Santa Cruz Air Base (Rio de Janeiro, RJ) allocated into three groups: pilots with lower total accumulated flight experience < 1,100 h (PC1, n = 7); pilots with higher total accumulated flight experience ≥ 1,100 h (PC2, n = 6); military non-pilots (CONT, n = 21). Data collection included anthropometric measurements, total blood count, lipidogram, markers of oxidative stress, and serum NMR-based metabolomics. RESULTS: In comparison with controls (p < 0.05), pilots exhibited decreased levels of white blood cells (-13%), neutrophils (-15%), lymphocytes (-20%), alfa-glucose (-13%), lactate (-26%), glutamine (-11%), histidine (-20%), and tyrosine (-11%), but higher isobutyrate (+ 10%) concentrations. Significant correlations were found between lactate vs. amino acids in CONT (r = 0.55-0.68, p < 0.001), and vs. glutamine in PC2 (r = 0.94, p = 0.01). CONCLUSION: Fighter pilots with lower experience showed a dysregulation in immune-metabolic function in comparison with controls, which seemed to be counteracted by the accumulation of flight hours. Those findings might have implications for the health preservation and operational training of fighter pilots.

Military Sexual Trauma and Menopause Symptoms Among Midlife Women Veterans.

BACKGROUND: Sexual assault and/or sexual harassment during military service (military sexual trauma (MST)) can have medical and mental health consequences. Most MST research has focused on reproductive-aged women, and little is known about the long-term impact of MST on menopause and aging-related health. OBJECTIVE: Examine associations of MST with menopause and mental health outcomes in midlife women Veterans. DESIGN: Cross-sectional. PARTICIPANTS: Women Veterans aged 45-64 enrolled in Department of Veterans Affairs (VA) healthcare in Northern California between March 2019 and May 2020. MAIN MEASURES: Standardized VA screening questions assessed MST exposure. Structured-item questionnaires assessed vasomotor symptoms (VMS), vaginal symptoms, sleep difficulty, depressive symptoms, anxiety symptoms, and posttraumatic stress disorder (PTSD) symptoms. Multivariable logistic regression analyses examined associations between MST and outcomes based on clinically relevant menopause and mental health symptom thresholds. KEY RESULTS: Of 232 participants (age = 55.95 ± 5.13), 73% reported MST, 66% reported VMS, 75% reported vaginal symptoms, 36% met criteria for moderate-to-severe insomnia, and almost half had clinically significant mental health symptoms (33% depressive symptoms, 49% anxiety, 27% probable PTSD). In multivariable analyses adjusted for age, race, ethnicity, education, body mass index, and menopause status, MST was associated with the presence of VMS (OR 2.44, 95% CI 1.26-4.72), vaginal symptoms (OR 2.23, 95% CI 1.08-4.62), clinically significant depressive symptoms (OR 3.21, 95% CI 1.45-7.10), anxiety (OR 4.78, 95% CI 2.25-10.17), and probable PTSD (OR 6.74, 95% CI 2.27-19.99). Results did not differ when military sexual assault and harassment were disaggregated, except that military sexual assault was additionally associated with moderate-to-severe insomnia (OR 3.18, 95% CI 1.72-5.88). CONCLUSIONS: Exposure to MST is common among midlife women Veterans and shows strong and independent associations with clinically significant menopause and mental health symptoms. Findings highlight the importance of trauma-informed approaches to care that acknowledge the role of MST on Veteran women's health across the lifespan.

Risk Factors for Delayed Treatment of Gonorrhea and Chlamydia in Active-Duty Service Members.

BACKGROUND: Sexually transmitted infections including gonorrhea and chlamydia are common in the active-duty military population, with historically higher rates than their civilian counterparts. Prevention and screening are 2 of the main strategies used to reduce the chronic medical complications and costs associated with untreated gonorrhea and chlamydia; however, there is little information in the literature regarding treatment time after a positive screening. To our knowledge, there has not yet been a study regarding delayed treatment of gonorrhea and chlamydia in the active-duty population. METHODS: We performed a population-based retrospective observational study on active-duty service members (ADSMs) diagnosed with gonorrhea and chlamydia from 2010-2019. Statistical analysis was performed to determine differences in treatment times for key demographics. This study was reviewed and approved by the Brooke Army Medical Center Institutional Review Board. RESULTS: Average treatment time was 3.5 days for individuals with chlamydia and 5 days for those with gonorrhea. Treatment within 2 weeks was met for 94% of people diagnosed with chlamydia and 91% of people diagnosed with gonorrhea. Delay in treatment times for chlamydia were seen in men, ages 25-34, full-time active-duty service members, those with a history of prior infection, and soldiers in the Army. Gonorrhea treatment times were delayed in men, members of the Coast Guard, ages 35-44, and those with a history of prior infection. CONCLUSIONS: Significant differences in treatment time were seen based on sex, age, branch of service, rank, and history of prior infection.