Tobacco and nicotine use among active component U.S. military service members: a comparison of 2018 estimates from the Health Related Behaviors Survey and the Periodic Health Assessment.

This study compared estimates of the prevalence of and risk factors for tobacco and nicotine use obtained from the 2018 Health Related Behaviors Survey (HRBS) and Periodic Health Assessment (PHA) survey. The HRBS and the PHA are important Department of Defense sources of data on health behavior collected from U.S. military service members. While their collection methods differ, some survey questions are similar, which provides an opportunity to compare survey estimates. Active duty service members consistently reported a much lower prevalence of all types of tobacco and nicotine use on the PHA compared to the HRBS: cigarettes (11.1% vs. 18.4%), e-cigarettes (7.3% vs. 16.2%), chewing tobacco (9.7% vs. 13.4%), any tobacco or nicotine use (25.3% vs. 37.8%), and use of 2 or more tobacco or nicotine products (5.8% vs. 17.4%). Associations between tobacco and nicotine use as well as demographic and other behavioral variables were fairly similar, including age, sex, education, race and ethnicity, rank, and alcohol use. The associations with service branch, body mass index, and sleep were inconsistent. This results of this study suggest that the PHA can provide timely information on trends in military tobacco and nicotine use over time, but much higher estimates from the confidential, voluntary HRBS reported in this study suggest that the command-directed PHA may substantially underestimate the prevalence of all types of tobacco and nicotine use.

Coverage of HIV pre-exposure prophylaxis (PrEP) within the active duty U.S. military, 2023.

Estimates of HIV pre-exposure prophylaxis (PrEP) coverage in the U.S. military, defined as the proportion of the persons taking HIV PrEP out of the estimated number of persons who had indications for it, have never been published. The objective of this study was to provide an estimate of HIV PrEP coverage comparable to U.S. civilian estimates. The population with indications for HIV PrEP was obtained from the Department of Defense 2018 Health Related Behaviors Survey, a stratified random sample of members of all military service branches. The military PrEP coverage estimate of 31.6% in 2023 was lower than the national U.S. estimate of 36.0% in 2022. Among the military population of men who have sex with men (MSM), an estimated 24.6% of service members had indications for PrEP, similar to the national estimate of 24.7%. MSM comprised 66% of all military service members with HIV PrEP indications, compared to 40% in the U.S. general population. The U.S. military should continue deliberate, sustained, and effective actions to address sexual health inequities among MSM, aligned and coordinated with societal efforts including improved coverage of HIV PrEP to prevent HIV transmission.

Health behavior profiles and association with mental health status among US active-duty service members.

Introduction: This study investigated the clustering of health behaviors among US active duty servicemembers (ADSM) into risk profiles and explored the association between these profiles with ADSM sociodemographic characteristics and mental health status. Methods: This study utilized secondary data from the 2018 Health Related Behaviors Survey (HRBS), a Department of Defense (DoD) self-administered online survey. Health behaviors included physical activity, screen use, sleep habits, tobacco/substance use, alcohol drinking, preventive health care seeking and condom use at last sex/having multiple sexual partners. Past-year mental health status was measured using the Kessler Screening Scale for Psychological Distress (K6). Latent class analysis (LCA) on health behaviors was used to cluster ADSMs into risk profiles. Multivariable logistic model was used to examine whether ADSM characteristics and mental health status were associated with ADSMs' risk profiles. Results: The LCA identified a four-class model that clustered ADSMs into the following sub-groups: (1) Risk Inclined (14.4%), (2) High Screen Users (51.1%), (3) Poor Sleepers (23.9%) and (4) Risk Averse (10.6). Over a tenth (16.4%) of ADSMs were categorized as having serious psychological distress. Being male, younger, less educated, in the Army, Marine Corps or Navy were associated with higher odds of being Risk Inclined (AOR ranging from 1.26 to 2.42). Compared to the reference group of Risk Adverse ADSMs, those categorized as Risk Inclined (AOR: 8.30; 95% CI: 5.16-13.36), High Screen Users (AOR: 2.44; 95% CI: 1.56-3.82) and Poor Sleepers (AOR: 5.26; 95% CI: 3.38-8.19) had significantly higher odds of having serious psychological distress. Discussion: Study findings suggest opportunities to tailor behavioral and health promotion interventions for each of the distinct risk profiles. For example, ADSM described as Risk Inclined may benefit from preventive mental health services. Solutions for ADSM described as Poor Sleepers may include education on sleep hygiene; instituting duty schedules; and shifting military cultural norms to promote sleep hygiene as a pathway to optimal performance and thus military readiness. ADSM with low-risk behavior profiles such as those described as Risk Averse may prove beneficial in the roll-out of interventions as they act as peer-educators or mentors.

Impact of Sleep Profiles on Multimorbidity Among US Active-Duty Service Members in the 2018 Health-Related Behaviors Survey.

Purpose: Sleep is a modifiable factor affecting chronic diseases and conditions in the Active-Duty (AD) United States (US) military population. This study assesses the impact of reported sleep health behaviors and sleep profiles on reported multimorbidity in active-duty service members (ADSMs). Participants and methods: The study used a military representative sample of 17,166 active duty SMs from the 2018 Department of Defense Health Related Behaviors Survey (HRBS) to explore sleep patterns and profiles, and medical conditions. Multimorbidity was defined as the presence of two or more medical conditions which we limited to include obesity, hypertension, and hyperlipidemia. The adjusted odds ratios for six sleep-related health behaviors and their unobservable sleep profiles were calculated using a weighted multinomial logistic model. Results: Sleep-related health behaviors were associated with increased odds of obesity, hypertension, and hyperlipidemia. We found higher odds of reported multimorbidity in SMs who reported lack of energy due to poor sleep (adjusted odds ratio [aOR] = 2.35, 95% CI:1.88-2.93), sleep 6 hours or less per night (aOR = 1.95, 95% CI:1.53-2.50), trouble sleeping (aOR = 2.19, 95% CI:1.76-2.72), and use of sleep medications (aOR = 2.10, 95% CI:1.64-2.68). Latent class analysis (LCA) identified three unobservable sleep profiles in SMs: minimal or low-risk sleep patterns (37.43%), moderate-risk sleep patterns (31.11%), and high-risk sleep patterns (31.46%). SMs with high-risk sleep patterns were significantly associated with reported multimorbidity (adjusted odds ratio [aOR] = 3.54, 95% CI:2.75-4.56). Conclusion: We found a strong association between sleep-related health behaviors and their unobservable sleep profiles with multimorbidity in this AD population. Future studies should investigate whether other chronic diseases may be influenced by sleep impairment in the US military population.

Perceived Health Status and Medical Conditions Among US Active-Duty Service Members.

Purpose: This paper investigates the association between self-reported perceived health status and doctor-informed medical conditions among US active duty service members (ADSM). Methods: Data are from the 2018 Health-Related Behaviors Survey - a cross-sectional survey weighted to represent the US military (N = 17166). Perceived good health status was defined as having a response choice of "good", "very good", or "excellent" to the question: Would you say your overall physical health is ___? Medical conditions were based on self-reported presence of nine clinical conditions. Analysis included weighted prevalence and log-binomial regression models to explore relationships between ADSM characteristics with perceived good health status as well as concordance between perceived status and medical conditions. Results: ADSM rated their health to be excellent (14.6%), very good (37.7%), good (36.2%), fair (9.7%) and poor (1.7%). About 88.5% perceived a good (to excellent) health status. Perceived good health status was negatively associated with the number of medical conditions present (adjusted odds ratio (aOR): ranging from 0.78 to 0.92) as well as several health behaviors (aOR): ranging from 0.86 to 0.98) and other sociodemographic factors. Among all ADSMs, 51% perceived good health in the absence of medical conditions, while 8% perceived poor health status in the presence of medical conditions. Concordance between perceived health status and medical conditions was significantly lower among ADSM who were older (aOR: 0.61; 95% CI: 0.54-0.69), with dependent children (aOR: 0.89; 95% CI: 0.84-0.95), or had been deployed (aOR: 0.89, 95% CI: 0.84-0.95). Conclusion: The prevalence of perceived good health status among ADSMs was consistent with those documented in the general US population. The interrelationships between ADSM's perceptions, medical conditions and sociodemographic characteristics may have implications for their health literacy and utilization of health services. Study findings suggest that interventions promoting healthy behaviors, health literacy and treatment-seeking may influence perceived health status and mitigate medical conditions among ADSM, thus improving the US Military readiness, resilience and mission success.

Suicidal Behaviors Among Active-Duty US Service Members: Data from the 2018 Health-Related Behaviors Survey.

Background: This study aimed to 1) determine the prevalence of past-year suicidal ideation (SI) and attempts (SA) among active-duty SMs; 2) determine whether differences exist by age, sex, and race; and 3) assess whether prevalence estimates vary by risk profiles of mental health conditions and substance use. Methods: Data were from the 2018 Health-Related Behavior Survey (HRBS), a cross-sectional survey of active-duty SMs (n = 17,166). We used the logistic model to identify the factors of SI and SA and latent class analysis (LCA) to identify the risk profiles. Results: Among active duty SMs, 8.26% had SI and 1.25% had SA in the past year. Gender and age have been shown to influence how race might contribute to suicidal behaviors. Mental health conditions were associated with higher odds of SI and SA, as were younger ages; LGB identity; being separated, divorced, or widowed; use of e-cigarettes, dual use of e-cigarettes and cigarettes, or drugs; and history of deployment of less than 12 months. Frequencies of cigarette and e-cigarette use were also associated with SI and SA, indicating the odds were increasing by 0.3% for every additional cigarette or e-cigarette used. Five risk profiles were identified: class 1 (illegal drug use), class 2 (mental health needs with tobacco and alcohol use), class 3 (mental health conditions only), class 4 ("low risk" SMs with low levels of illegal drug use, mental health visits, tobacco use, and alcohol use), and class 5 (alcohol use). Compared to class 4 ("low risk"), all other risk profiles were associated with increased odds of suicidal behaviors. Conclusion: Despite the resources and increased access provided for mental health support, the prevalence of SI among active-duty SMs is greater than in the general population of the same age, likely due to additional military exposures and stressors.

mAb therapy controls CNS-resident lyssavirus infection via a CD4 T cell-dependent mechanism.

Infections with rabies virus (RABV) and related lyssaviruses are uniformly fatal once virus accesses the central nervous system (CNS) and causes disease signs. Current immunotherapies are thus focused on the early, pre-symptomatic stage of disease, with the goal of peripheral neutralization of virus to prevent CNS infection. Here, we evaluated the therapeutic efficacy of F11, an anti-lyssavirus human monoclonal antibody (mAb), on established lyssavirus infections. We show that a single dose of F11 limits viral load in the brain and reverses disease signs following infection with a lethal dose of lyssavirus, even when administered after initiation of robust virus replication in the CNS. Importantly, we found that F11-dependent neutralization is not sufficient to protect animals from mortality, and a CD4 T cell-dependent adaptive immune response is required for successful control of infection. F11 significantly changes the spectrum of leukocyte populations in the brain, and the FcRγ-binding function of F11 contributes to therapeutic efficacy. Thus, mAb therapy can drive potent neutralization-independent T cell-mediated effects, even against an established CNS infection by a lethal neurotropic virus.

Race, ethnicity, F8 variants, and inhibitor risk: analysis of the "My Life Our Future" hemophilia A database.

BACKGROUND: Several studies have suggested Black and Hispanic hemophilia A (HA) patients in the United States suffer higher incidences of neutralizing anti-FVIII antibodies (inhibitors) than their White counterparts. The possible influence of nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in the F8 gene sequence has been proposed as a possible race-associated contributing factor. Some earlier studies indicated that intron-22 inversion mutations carry a lower inhibitor risk than other mutations resulting in large F8 gene disruptions. OBJECTIVES: The objectives of the study were to test the following hypotheses: (1) The risk of developing an inhibitor differs among racial/ethnic groups in the United States, (2) specific non-HA-causing ns-SNPs in the F8 gene are correlated with inhibitor risk, and (3) inhibitor risk associated with intron-22 inversions mutations is similar to that associated with other large structural changes in the F8 gene. METHODS: Adjusted logistic regression analysis of the "My Life Our Future" database containing demographic, clinical, and F8 sequence data from >6000 mild, moderate, and severe HA participants. RESULTS: Black and Hispanic severe HA subjects had a higher inhibitor risk than non-Hispanic Whites (adjusted odds ratio = 1.65, 95% CI: 1.22-2.21 and adjusted odds ratio = 1.88, 95% CI: 1.43-2.48), confirming this racial/ethnic/medical disparity; however, F8 ns-SNPs were not associated with inhibitor development. There was no difference in inhibitor risk among severe HA subjects with an intron-22 inversion vs other large structural changes in the F8 gene. CONCLUSIONS: Nonpathogenic ns-SNPs in the F8 gene are not correlated with inhibitor risk. Inhibitor risk associated with intron-22 inversion mutations is similar to that of other large structural changes in F8 that preclude intact FVIII expression.

Unintended pregnancy among U.S. military active duty servicemembers: Estimates for 2018 and trends since 2005.

OBJECTIVES: To evaluate the prevalence of and factors associated with unintended pregnancy in the past 12 months among women and men in the United States (U.S.) military in 2018, as well as trends in unintended pregnancy between 2005 and 2018. STUDY DESIGN: This was a cross-sectional study using the 2018 Department of Defense Health Related Behaviors Survey of active duty servicemembers. We selected a stratified random sample from members of all military service branches and used weighted logistic regression models to identify associated independent factors. A 9.6% weighted response rate to the online survey resulted in 16,806 active duty servicemembers analyzed; 4993 women aged 17 to 44 years and 11,813 men aged 17 to 45+ years. We used data from five independent surveys: 2005, 2008, 2011, 2015, and 2018 to examine trends over time. RESULTS: A total of 5.6% (95% CI: 4.5%-6.7%) of servicewomen reported unintended pregnancy and 2.4% (95% CI: 1.9%-2.9%) of servicemen reported to have caused unintended pregnancy. Unintended pregnancy was associated with contraception nonuse, younger age, and being either married or cohabiting. CONCLUSION: The decrease in prevalence of unintended pregnancy among U.S. servicemembers since 2005 mirrors the general U.S. POPULATION: Differing contraception policies during basic training across military services may influence rates of unintended pregnancy. Unintended pregnancies place a large burden on the military healthcare system, as the majority of women serving in the military are of reproductive age, and thus require care before, during, and for years after giving birth. IMPLICATIONS: Unintended pregnancy among U.S. military servicewomen relatively mirrors that seen in the U.S. POPULATION: Contraceptive policies affect unintended pregnancy throughout servicemembers' duration of service. As they are more likely to live in states which restrict access to abortion services, servicewomen with unintended pregnancy may face increased obstacles to care.

Sport-related Structural Brain Injury in High School and College American Football Athletes, 2002-2020: Effect of Lystedt Law.

BACKGROUND: A previous report revealed an average of 7.2 (0.67 per 100,000 participants) sport-related structural brain injuries (SRSBIs) with macroscopic lesions per year in high school (HS) and college football players. The Lystedt law and other rule changes have been implemented with intent to reduce the risk of brain injury in football. HYPOTHESIS: To update the profile of SRSBIs in HS and college football players and evaluate the efficacy of legislation intended to reduce brain injuries. STUDY DESIGN: Descriptive epidemiology study. LEVEL OF EVIDENCE: Level 4. METHODS: We retrospectively reviewed 18 academic years (July 2002 through June 2020) of SRSBIs catalogued by the National Registry of Catastrophic Sports Injuries. The incidence of SRSBIs was assessed at the HS level during the pre (July 2002 through June 2009), transitional (July 2009 through June 2014), and post (July 2014 through June 2020) universal adoption time periods of the Lystedt law. In addition, the incidence of SRSBIs during the second half of the study (2011-2012 through 2019-2020) was compared with the first half of the study (2002-2003 through 2010-2011). RESULTS: During the study period, there was a total of 228 SRSBIs (12.7 per year, 1.01 per 100,000 participants): 212 (93%, 11.8 per year, 1.00 per 100,000) in HS athletes and 16 (7%, 0.89 per year, 1.17 per 100,000) in college athletes. There were 52 fatalities (2.9 per year, 0.22 per 100,000 participants) with 46 (2.56 per year, 0.22 per 100,000) in HS athletes and 6 (0.33 per year, 0.43/100,000) in college athletes. There was no significant difference in risk of HS total SRSBIs or fatalities during the 3 Lystedt periods. The risk of combined SRSBI cases [relative risk (RR) = 1.22, P = 0.13] and fatalities (RR = 1.20, P = 0.52) was similar in the second half of the study compared with the first half of the study. CONCLUSION: Despite implementation of rule changes intended to reduce head injury, in particular the Lystedt law, the incidence of SRSBIs has remained unchanged. Further research is necessary to develop effective prevention programs for SRSBIs. CLINICAL RELEVANCE: SRSBIs remain a persistent problem in HS and college American football. The recent head injury rule changes have not been effective at reducing SRSBIs.

The Mediating Role of Family Acceptance and Conflict on Suicidality among Sexual and Gender Minority Youth.

INTRODUCTION: Prior research suggests sexual and gender minority (SGM) youth are profoundly impacted by levels of parental support. This study assessed mediating effects of generalized family acceptance and conflict on lifetime suicidal behaviors among a large diverse sample comprising both SGM and non-SGM youth in early adolescence, when intervention to optimize family dynamics may be critical. MATERIALS: Using data from the first-year follow-up of the Adolescent Brain Cognitive Development Study based in the United States, mediation was tested using a binary logistic regression model fitted with a generalized structural equation. Models included SGM status as the independent variable, family acceptance or family conflict sum score as the mediator, and the presence of lifetime suicidal behaviors as the dependent variable. Models adjusted for age, birth-assigned sex (as reported by the parent/guardian), and race/ethnicity. RESULTS: Of 11,235 youths, lifetime suicidal behaviors were reported by 1.5% (n = 164). Youths with SGM identities reported 40% less parental acceptance and 47% greater family conflict, compared to non-SGM peers. Both parental acceptance and family conflict partially mediated associations between SGM identification and odds of lifetime suicidal behavior (ps = .001). CONCLUSIONS: Identification of modifiable risk factors for suicidality in this vulnerable population, including parental acceptance and family conflict, is critical to improving health outcomes. Clinicians should work with SGM youth and their families starting in childhood to optimize family dynamics and bolster acceptance to potentially reduce adverse health outcomes. HIGHLIGHTSYouths with SGM identity reported 40% less parental acceptance than non-SGM peers.Parental acceptance was associated with lower odds of lifetime suicidal behaviors.Family factors partially mediated associations between SGM status and suicidal behaviors.

Evaluation of Gender Disparity in Tactical Combat Casualty Care.

INTRODUCTION: Women comprise nearly 19% of the U.S. military and now serve in almost all operational roles, increasing their risk of combat trauma and injuries.3 Data from the Joint Trauma Registry during Operation Enduring Freedom shows that battle-injured females had a higher case fatality rate at 36% compared to their male counterparts at 17%.1 The Tactical Combat Casualty Care curriculum is used to prepare battlefield medics to provide immediate care to wounded service members, but fails to address differences in the care of female versus male casualties. The students, who are presented with life-threatening injuries in simulated trauma scenarios, may be slower to assess, identify, and treat injuries in female patients as compared with male patients. MATERIALS AND METHODS: This observational program analysis was reviewed by the Uniformed Services University Human Research Protections Program and approved for execution as an exempt protocol under the provision of 32 CFR 219.104(d)(1). The study assessed the performance of male and female Mexican military personnel during a Tactical Combat Casualty Care course, using standardized trauma scenarios. Anatomically, correct male and female manikins were used to compare response time for different gender patients presenting with the same injuries. RESULTS: There was a statistically significant increase in time required to complete an initial blood sweep, identify a gunshot wound to the chest, and call for medical evacuation when treating a female patient compared to a male patient. CONCLUSIONS: A lack of female representation in trauma training may have contributed to the higher case fatality rate of female soldiers compared to male soldiers during Operation Enduring Freedom. Female live actors and Gender Retrofit Kits can augment trauma casualty assessment and treatment training scenarios and better prepare our forces to respond to life-threatening emergencies.

Differences in Disease Non-battle Injury Between Combatant Commands.

INTRODUCTION: Disease and non-battle injury (DNBI) have historically been a major or primary medical burden in expeditionary military populations. The United States has multiple deployed populations conducting operations across the world. This study aims to determine if DNBI rates are different between military populations by comparing the United States Africa Command (USAFRICOM) and United States Central Command (USCENTCOM) areas of responsibility. MATERIALS AND METHODS: The study period was from January 1, 2017 to December 31, 2021. Individual evacuation data including date, necessary specialty care, and combatant command (CCMD) were acquired via United States Transportation Command Regulating and Command & Control Evacuation System. Total population data was acquired from USAFRICOM and USCENTCOM headquarters. Total inpatient and outpatient encounters at each CCMD were acquired via Theater Medical Data Store. The proportions and evacuation rates of DNBI types within USAFRICOM and USCENTCOM were compared. RESULTS: USCENTCOM had significantly higher proportions of outpatient and inpatient services for mental disorders, musculoskeletal diseases, and neurologic conditions compared to USAFRICOM. USCENTCOM had a significantly lower evacuation rate compared to USAFRICOM for every year analyzed: 2017 (P-value < .0001; relative risk [RR] = 0.834; 95% CI = 0.80-0.87), 2018 (P-value < .0001; RR = 0.818; 95% CI = 0.78-0.85), 2019 (P-value < .0001; RR = 0.785; 95% CI = 0.75-0.82), 2020 (P-value < .0001; RR = 0.889; 95% CI = 0.84-0.94), and 2021 (P-value < .0001; RR = 0.868; 95% CI = 0.83-0.91). CONCLUSIONS: The evacuation rates of different categories of DNBI vary between CCMDs. There will be CCMD-specific factors that impact the effectiveness of initiatives to reduce the DNBI burden.

Comorbidities in Clinical and Polysomnographic Features of Obstructive Sleep Apnea: A Single Tertiary Care Center Experience.

BACKGROUND: Research on obstructive sleep apnea (OSA) is inadequate in Saudi Arabia, particularly among patients with comorbidities. This study investigates comorbidities in patients with different severity of apnea based on the Apnea-Hypopnea Index (AHI). METHODS: The retrospective charts review that included a cohort of 4391 patients who underwent polysomnography (PSG) between 2003 and 2019. The AHI is classified into four ordinal groups: normal, mild, moderate, and severe. Ordinal logistic regression was used to model proportional odds of a higher AHI category. RESULTS: Gender was distributed equally in the study sample. The average age was 49.6 ± 14.8 years and the average AHI was 16.1 ± 22 per hour. Hypertension (43.2%) and diabetes mellitus (37.3%) were the most common comorbidities: Mild OSA 28.9%, Moderate OSA 15.6%, and severe 16.4%. The severity of apnea increased with age and BMI classes. The prevalence of hypertension increased with the severity of apnea: 42.9% in mild, 47.4% in moderate, and 54.6% in severe AHI. The prevalence of coronary artery disease (CAD), congestive heart failure (CHF), and diabetes mellitus (DM) increased with the severity of apnea. Comorbidities was more among OSA patients with excessive sleepiness. After adjustment for age and gender, greater proportional odds of severe AHI were observed in males (aOR = 1.8), 30-59 years (aOR = 2.064), 60 years or above (aOR = 2.873), obese class II (aOR = 2.016), obese class III (aOR = 2.527), and in patients with hypertension (aOR = 1.272). CONCLUSION: Hypertension and obesity were highly prevalent in the study cohort and were associated with greater proportional odds of severe AHI.

Proportion of Navy Recruits Diagnosed With Symptomatic Stress Fractures During Training and Monetary Impact of These Injuries.

BACKGROUND: Lower extremity stress fractures result in lost time from work and sport and incur costs in the military when they occur in service members. Hypovitaminosis D has been identified as key risk factor in these injuries. An estimated 33% to 90% of collegiate and professional athletes have deficient vitamin D levels. Other branches of the United States military have evaluated the risk factors for stress fractures during basic training, including vitamin D deficiency. To the best of our knowledge, a study evaluating the correlation between these injuries and vitamin D deficiency in US Navy recruits and a cost analysis of these injuries has not been performed. Cutbacks in military medical staffing mean more active-duty personnel are being deferred for care to civilian providers. Consequently, data that previously were only pertinent to military medical providers have now expanded to the nonmilitary medical community. QUESTIONS/PURPOSES: We therefore asked: (1) What proportion of US Navy recruits experience symptomatic lower extremity stress fractures, and what proportion of those recruits had hypovitaminosis vitamin D on laboratory testing? (2) What are the rehabilitation costs involved in the treatment of lower extremity stress fractures, including the associated costs of lost training time? (3) Is there a cost difference in the treatment of stress fractures between recruits with lower extremity stress fractures who have vitamin D deficiency and those without vitamin D deficiency? METHODS: We retrospectively evaluated the electronic medical record at Naval Recruit Training Command in Great Lakes, IL, USA, of all active-duty males and females trained from 2009 until 2015. We used ICD-9 and ICD-10 diagnosis codes to identify those diagnosed with symptomatic lower extremity stress fractures. Data collected included geographic region of birth, preexisting vitamin D deficiency, vitamin D level at the time of diagnosis, medical history, BMI, age, sex, self-reported race or ethnicity, hospitalization days, days lost from training, and the number of physical therapy, primary care, and specialty visits. To ascertain the proportion of recruits who developed symptomatic stress fractures, we divided the number of recruits who were diagnosed with a stress fracture by the total number who trained over that span of time, which was 204,774 individuals. During the span of this study, 45% (494 of 1098) of recruits diagnosed with a symptomatic stress fracture were female and 55% (604 of 1098) were male, with a mean ± SD age of 24 ± 4 years. We defined hypovitaminosis D as a vitamin D level lower than 40 ng/mL. Levels less than 40 ng/mL were defined as low normal and levels less than 30 ng/mL as deficient. Vitamin D levels were obtained at the discretion of the individual treating provider without standardization of protocol. Cost was defined as physical therapy visits, primary care visits, orthopaedic visits, diagnostic imaging costs, laboratory costs, hospitalizations, if applicable, and days lost from training. Diagnostic studies and laboratory tests were incorporated as indirect costs into initial and follow-up physical therapy visits. Evaluation and management code fee schedules for initial visits and follow-up visits were used as direct costs. We obtained these data from the Centers for Medicare & Medicaid Services website. Per capita cost was calculated by taking the total cost and dividing it by the study population. Days lost from training is based on a standardized government military salary of recruits to include room and board. RESULTS: We found that 0.5% (1098 of 204,774) of recruits developed a symptomatic lower extremity stress fracture. Of the recruits who had vitamin D levels drawn at the time of stress fracture, 95% (416 of 437 [95% confidence interval (CI) 94% to 98%]; p > 0.99) had hypovitaminosis D (≤ 40 ng/mL) and 82% (360 of 437 [95% CI 79% to 86%]; p > 0.99) had deficient levels (≤ 30 ng/mL) on laboratory testing, when evaluated. The total treatment cost was USD 9506 per recruit. Days lost in training was a median of 56 days (4 to 108) for a per capita cost of USD 5447 per recruit. Recruits with deficient vitamin D levels (levels ≤ 30 ng/mL) incurred more physical therapy treatment costs than did those with low-normal vitamin D levels (levels 31 to 40 ng/mL) (mean difference USD 965 [95% CI 2 to 1928]; p = 0.049). CONCLUSION: The cost of lost training and rehabilitation associated with symptomatic lower extremity stress fractures represents a major financial burden. Screening for and treatment of vitamin D deficiencies before recruit training could offer a cost-effective solution to decreasing the stress fracture risk. Recognition and treatment of these deficiencies has a role beyond the military, as hypovitaminosis and stress fractures are common in collegiate or professional athletes. LEVEL OF EVIDENCE: Level III, prognostic study.

Epidemiology of Exertional Rhabdomyolysis in the United States: Analysis of NEISS Database 2000 to 2019.

OBJECTIVE: There have been numerous case series of exertional rhabdomyolysis (ER) but no comprehensive studies investigating the incidence of ER in the civilian athletic population in the United States (US). METHODS: A retrospective review of patients with ER presenting to emergency departments in the US over a 20-year period between 2000 and 2019 was performed using the National Electronic Injury Surveillance System (NEISS) database. RESULTS: The national estimate of hospital visits in the US for ER during the 20-year period was 40,654 (0.66 per 100,000 population). There was a 10-fold increase in the incidence of ER from the first to the second decade. The odds of ER were 3.77 (95% CI 3.67-3.86, P < .0001) times higher for males (31,921, 78.5%, 1.06 per 100,000) than females (8,733, 21.5%, 0.28 per 100,000) and 3.82 (95% CI 3.71-3.93, P < .0001) higher in African Americans (33.6, 0.93 per 100,000) than white patients (53%, 0.24 per 100,000). American football (3,064, 7.5%) was responsible for 43.9% of the sports-induced ER cases. The majority (67.3%) of ER cases occurred between the ages of 16 and 35 years old. The majority of patients required hospitalization (26,550, 65.3%). CONCLUSIONS: The number of ER cases presenting to emergency departments in the US increased from 2000-2009 to 2010-2019. Young males and African Americans are at highest risk of ER. There was a high rate of hospitalization.

Baseline Aerobic Fitness in High School and College Football Players: Critical for Prescribing Safe Exercise Regimens.

BACKGROUND: Nontraumatic fatalities occur on a regular basis in high school (HS) and college football athletes, primarily in obese linemen performing high-intensity exercise. One contributing factor to these deaths may be a mismatch between baseline aerobic (cardiorespiratory) fitness and exercise regimens. HYPOTHESIS: There is a wide range of aerobic fitness in HS and college football players. Body mass index (BMI) is a safe and simple method for estimating baseline aerobic fitness. STUDY DESIGN: Retrospective cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: A retrospective review was performed on 79 HS football athletes who had VO2Peak (mL·kg-1·min-1) measured during the offseason. Multivariate regression analysis was used to determine if BMI (obese, overweight, and normal; kg/m2), position played (linemen vs other), year in school (freshmen vs other), and/or race (African American vs White) were risk factors for poor aerobic fitness. A separate cohort of 135 (48 HS; 87 college) football athletes performed a 6-minute run test to determine speed (miles/min), extrapolate VO2Max, and calculate reference values for suggested upper threshold safe starting speeds (85% of maximum) for aerobic training based on BMI. The relationship between BMI and VO2Peak was assessed. The exercise regimens (speeds) of 2 collegiate football fatalities from the public domain were used to predict their VO2Max values. RESULTS: Mean VO2Peak (mL·kg-1·min-1) was 38.5 ± 8.6 (range 19.1-60.6); when grouped by BMI, low scores (<40) were found in 87.5% of obese (32.4 ± 7.7), 47.8% of overweight (40.8 ± 7.6), and 45.2% of normal (41.4 ± 7.8) athletes. VO2Peak was significantly lower in linemen (32.8 ± 6.4; P = 0.007) compared with nonlineman (41.8 ± 7.9), and in obese players (by BMI; 32.4; P = 0.019) compared with nonobese players (41.4 ± 7.6), but did not differ by age, year in school, or race. Means for speed (min/mile) and extrapolated VO2Max (mL·kg-1·min-1) for the 6-minute run test by BMI groups were both significantly different (P = 0.001) for normal (7.0 ± 0.6; 51.1 ± 2.6), overweight (7.6 ± 0.8; 46.5 ± 3.2), and obese (8.9 ± 1.5; 36.8 ± 5.9) athletes. There was a significant negative correlation (r = -0.551; P = 0.001; R2 = 0.304) between VO2Peak and BMI. Safe starting speed recommendations for running 1 mile range from 7.3 to 12.1 min/mile for BMIs 20 to 40 kg/m2 for HS and college athletes. For the 2 fatalities (mean, BMI of 36.5 kg/m2) repetitive sprint speeds were 49 and 89% higher than our safe starting speeds for their BMI. CONCLUSION: A large spectrum of baseline aerobic fitness was noted in HS and college football players. Obese players and linemen had statistically lower baseline aerobic fitness, a major risk factor for possible heat illness. BMI is an acceptable surrogate for VO2Peak and can be employed to develop safe training regimens without the need for a maximum fitness test, which can place the athlete at risk for a medical event. CLINICAL RELEVANCE: Knowledge of BMI provides an estimate of baseline aerobic fitness and a foundation for prescribing safe, individualized exercise regimens.

Gait analysis in a rat model of traumatic brain injury.

Gait disruptions following traumatic brain injury (TBI) are noted in the clinical population. To date, thorough analysis of gait changes in animal models of TBI to allow for correlation of pathological alterations and utilization of this as a therapeutic outcome have been limited. We therefore assessed gait using the DigiGait analysis system as well as overall locomotion using the Beam Walk test in adult male Sprague-Dawley rats following a commonly used model of TBI, parietal lobe controlled cortical impact (CCI). Rats underwent DigiGait baseline analysis 24 h prior to injury, followed by a moderate CCI in the left parietal lobe. Performance on the DigiGait was then assessed at 1, 3, 7, and 14 days post-injury, followed by histological analysis of brain tissue. Beam walk analysis showed a transient but significant impairment acutely after injury. Despite observance of gait disturbance in the clinical population, TBI in the parietal lobe of rats resulted in limited alterations in hind or forelimb function. General hindlimb locomotion showed significant but transient impairment. Significant changes in gait were observed to last through the sub-acute period, including right hindpaw angle of rotation and left forelimb and right hindlimb swing phase duration. Slight changes that did not reach statistical significant but may reflect subtle impacts of TBI on gait were reflected in several other measures, such as stride duration, stance duration and stance width. These results demonstrate that moderate-severe injury to the parietal cortex and underlying structures including corpus callosum, hippocampus, thalamus and basal ganglia result in slight changes to gait that can be detected using the Digigait analysis system.