Sleeping for One Week on a Temperature-Controlled Mattress Cover Improves Sleep and Cardiovascular Recovery

Body temperature should be tightly regulated for optimal sleep. However, various extrinsic and intrinsic factors can alter body temperature during sleep. In a free-living study, we examined how sleep and cardiovascular health metrics were affected by sleeping for one week with (Pod ON) vs. without (Pod OFF), an active temperature-controlled mattress cover (the Eight Sleep Pod). A total of 54 subjects wore a home sleep test device (HST) for eight nights: four nights each with Pod ON and OFF (>300 total HST nights). Nightly sleeping heart rate (HR) and heart rate variability (HRV) were collected. Compared to Pod OFF, men and women sleeping at cooler temperatures in the first half of the night significantly improved deep (+14 min; +22% mean change; p = 0.003) and REM (+9 min; +25% mean change; p = 0.033) sleep, respectively. Men sleeping at warm temperatures in the second half of the night significantly improved light sleep (+23 min; +19% mean change; p = 0.023). Overall, sleeping HR (-2% mean change) and HRV (+7% mean change) significantly improved with Pod ON (p < 0.01). To our knowledge, this is the first study to show a continuously temperature-regulated bed surface can (1) significantly modify time spent in specific sleep stages in certain parts of the night, and (2) enhance cardiovascular recovery during sleep.

Development and cross-validation of a circumference-based predictive equation to estimate body fat in an active population

Objective

The U.S. Army uses sex-specific circumference-based prediction equations to estimate percent body fat (%BF) to evaluate adherence to body composition standards. The equations are periodically evaluated to ensure that they continue to accurately assess %BF in a diverse population. The objective of this study was to develop and validate alternative field expedient equations that may improve upon the current Army Regulation (AR) body fat (%BF) equations.

Methods

Body size and composition were evaluated in a representatively sampled cohort of 1904 active-duty Soldiers (1261 Males, 643 Females), using dual-energy X-ray absorptiometry (%BFDXA), and circumferences obtained with 3D imaging and manual measurements. Sex stratified linear prediction equations for %BF were constructed using internal cross validation with %BFDXA as the criterion measure. Prediction equations were evaluated for accuracy and precision using root mean squared error, bias, and intraclass correlations. Equations were externally validated in a convenient sample of 1073 Soldiers.

Results

Three new equations were developed using one to three circumference sites. The predictive values of waist, abdomen, hip circumference, weight and height were evaluated. Changing from a 3-site model to a 1-site model had minimal impact on measurements of model accuracy and performance. Male-specific equations demonstrated larger gains in accuracy, whereas female-specific equations resulted in minor improvements in accuracy compared to existing AR equations. Equations performed similarly in the second external validation cohort.

Conclusions

The equations developed improved upon the current AR equation while demonstrating robust and consistent results within an external population. The 1-site waist circumference-based equation utilized the abdominal measurement, which aligns with associated obesity related health outcomes. This could be used to identify individuals at risk for negative health outcomes for earlier intervention.

Relation of body surface area-to-mass ratio to risk of exertional heat stroke in healthy men and women

Risk of exertional heat stroke (EHS) is an ongoing challenge for United States military personnel, for athletes and for individuals with occupational stressors that involve prolonged activity in hot environments. Higher body mass index (BMI) is significantly associated with increased risk for EHS in activity duty U.S. Soldiers. During exercise, heat is generated primarily by contracting skeletal muscle (and other metabolically active body mass) and dissipated based on body surface area (BSA). Thus, in compensable environments, a higher BSA·mass-1 may be a benefit to heat dissipation and decrease the risk of EHS. The purpose of the present analysis was to test the hypothesis that BSA·mass-1 ratio is an important biophysical characteristic contributing to the risk of EHS. We employed a matched case-control approach, where each individual with a diagnosis of EHS was matched to five controls who were never diagnosed with EHS but were in the same unit and had the same job title. We used a multivariate conditional logistic regression model including variables of BSA·mass-1, sex, age, military rank, and race. BSA·mass-1 significantly predicted EHS risk (P = 0.006), such that people with higher BSA·mass-1 were at lower risk of developing EHS when controlling for other potential factors such as age and race. This relationship persisted after adjustment for other anthropometric measures of body size including weight, BMI, and BSA. These data suggest that biophysical factors play an important role in EHS risk, particularly in a healthy military-aged cohort of men and women.NEW & NOTEWORTHY With the impacts of climate change yielding higher average ambient temperatures over time, the incidence of EHS for individuals participating in outdoor activities may consequently increase. With the larger sample size in this study compared with prior research in this field, we were able to use various methods that had not been applied before. For example, we were able to mutually adjust for different measurements of body size to understand which metric had the highest association with EHS risk. Understanding factors that may be modifiable may be important for developing interventions to counteract the increased risk of EHS associated with climate change.

Sex Does Not Affect Changes in Body Composition and Insulin-Like Growth Factor-I During US Army Basic Combat Training

ABSTRACT

Roberts, BM, Staab, JS, Caldwell, AR, Sczuroski, CE, Staab, JE, Lutz, LJ, Reynoso, M, Geddis, AV, Taylor, KM, Guerriere, KI, Walker, LA, Hughes, JM, and Foulis, SA. Sex does not affect changes in body composition and insulin-like growth factor-I during US army basic combat training. J Strength Cond Res XX(X): 000-000, 2023-Insulin-like growth factor 1 (IGF-I) has been implicated as a biomarker of health and body composition. However, whether changes in body composition are associated with changes in IGF-I is unclear. Therefore, we examined the relationship between body composition changes (i.e., fat mass and lean mass) and total serum IGF-I levels in a large cohort of young men (n = 809) and women (n = 397) attending US Army basic combat training (BCT). We measured body composition using dual energy x-ray absorptiometry and total serum IGF-I levels during week 1 and week 9 of BCT. We found that pre-BCT lean mass (r = 0.0504, p = 0.082) and fat mass (r = 0.0458, p = 0.082) were not associated with pre-BCT IGF-I. Body mass, body mass index, body fat percentage, and fat mass decreased, and lean mass increased during BCT (all p < 0.001). Mean (±SD) IGF-I increased from pre-BCT (176 ± 50 ng·ml-1) to post-BCT (200 ± 50 ng·ml-1, p < 0.001). Inspection of the partial correlations indicated that even when considering the unique contributions of other variables, increases in IGF-I during BCT were associated with both increased lean mass (r = 0.0769, p = 0.023) and increased fat mass (r = 0.1055, p < 0.001) with no sex differences. Taken together, our data suggest that although changes in IGF-I weakly correlated with changes in body composition, IGF-I, in isolation, is not an adequate biomarker for predicting changes in body composition during BCT in US Army trainees.

Impact of mindfulness training and yoga on injury and pain-related impairment: a group randomized trial in basic combat training

Introduction

Service members are at risk for pain-related difficulties in functioning and physical injury. Previous studies suggest that mindfulness training (MT) and yoga may prevent these outcomes. The present study was designed to determine the impact of MT and yoga on the health, pain, and injury of Army trainees completing 10 weeks of basic combat training (BCT).

Methods

Platoons (≈40 trainees per platoon) were randomized to MT and yoga or training-as-usual in October to December 2020 at a large installation in the US. Self-reported outcomes were health, pain level, and pain impact on training, sleep, mood, and stress. Objective outcomes were injury-related medical encounters and number of diagnoses. The trial was registered at ClinicalTrials. Gov (NCT05550610).

Results

Intervention trainees reported significantly better health (OR = 1.05, 95% CI [1.00, 1.10]) and less impact of pain on training (OR = 0.81, 95% CI [0.74, 0.90]), sleep (OR = 0.88, 95% CI [0.81, 0.95]), mood (OR = 0.86, 95% CI [0.78, 0.96]), and stress (OR = 0.88, 95% CI [0.79, 0.98]). There was no significant difference in injury-related medical encounters (AOR = 0.70, 95% CI [0.48, 1.03]), but intervention trainees had fewer diagnoses (OR = 0.67, 95% CI [0.47, 0.95]) and were 30% less likely to have a first medical encounter at any time during BCT. This difference emerged 3 weeks into BCT.

Discussion

A combined MT and yoga intervention resulted in better trainee health. The US Army and other organizations requiring resilience under extreme stress should consider implementing MT and yoga to offset risks to employee health.

Predicting Postoperative Injury and Military Discharge Status After Knee Surgery in the US Army

BACKGROUND

Researchers have assessed postoperative injury or disability predictors in the military setting but typically focused on 1 type of surgical procedure at a time, used relatively small sample sizes, or investigated mixed cohorts with civilian populations.

PURPOSE

To identify the relationship between baseline variables and injury incidence or military discharge status in US Army soldiers after knee surgery.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were obtained from a repository containing personnel, performance, and medical records for all active-duty US Army soldiers. Multivariate logistic regressions were used to estimate the effects of numerous variables on postoperative injury or on medical discharge. Variable selection and model validation were conducted using the k-fold method.

RESULTS

A total of 7567 soldiers underwent knee surgery between 2017 and 2019. Meniscal procedures were the most common type of surgery (39%), and approximately 71% of the cohort had a postoperative injury. Significant predictors for sustaining a postoperative injury included having a previous nonknee injury (odds ratio [OR], 1.5), female sex (OR, 1.3), and Black race (OR, 1.2). Within 4 years after surgery, 17% of soldiers were discharged from the military because of knee-related disability. Significant predictors for discharge from duty included enlisted rank (OR, 2.3), recent fitness test failure (OR, 1.9), number of previous knee surgeries (OR, 1.7), and having a previous nonknee injury (OR, 1.6).

CONCLUSION

After knee surgery, nearly three-fourths of the soldiers in this cohort sustained a postoperative injury and almost one-fifth of soldiers were medically discharged from the military within 4 years. This study identified variables that indicate statistically increased risk for these postoperative outcomes and highlighted potentially modifiable factors.

The Risk of Menstrual Dysfunction Increases for Women during U.S. Army Basic Combat Training

PURPOSE

To determine whether changes in menstruation develop in female trainees during BCT and whether changes in body mass, body composition and/or physical activity are associated with menstrual interruption during BCT.

METHODS

Female trainees grouped according to self-reported menstrual status in the 12 months before BCT as having regular cycles (RC; n = 352) or MD ( n = 97) completed height, body mass, and body composition assessments and questionnaires before and after BCT. Fisher's exact test and Mann-Whitney U test were used to compare between-group differences in categorical and continuous variables, respectively. Among RC trainees, odds ratios were calculated to examine the influence of changes in body mass, lean mass, and fat mass on a trainee's likelihood to miss a period during BCT.

RESULTS

There were no differences in race, height, body mass, body mass index, or physical activity history at pre-BCT between RC and MD ( P > 0.05). Overall, 86% of trainees experienced changes to menstruation during BCT. RC were more likely than MD to have at least one period during BCT (81% vs 69%, respectively, P = 0.01). Among RC, gaining more body mass and lean mass and losing less fat mass were associated with increased odds of missing a period during BCT.

CONCLUSIONS

These findings demonstrate that most female trainees experience menstrual changes during BCT. Menstrual cycle interruptions do not appear to align with loss of body or fat mass.

US Army basic combat training alters the relationship between body mass index and per cent body fat

INTRODUCTION/BACKGROUND

As a proxy for adiposity, body mass index (BMI) provides a practical public health metric to counter obesity-related disease trends. On an individual basis, BMI cannot distinguish fat and lean components of body composition. Further, the relationship between BMI and body composition may be altered in response to physical training. We investigated this dynamic relationship by examining the effect of US Army basic combat training (BCT) on the association between BMI and per cent body fat (%BF).

METHODS

BMI and %BF were measured at the beginning (week 1) and end (week 9) of BCT in female (n=504) and male (n=965) trainees. Height and weight were obtained for BMI, and body composition was obtained by dual X-ray absorptiometry. Sensitivity and specificity of BMI-based classification were determined at two BMI thresholds (25 kg/m2 and 27.5 kg/m2).

RESULTS

A progressive age-related increase in fat-free mass index (FFMI) was observed, with an inflection point at age 21 years. In soldiers aged 21+, BMI of 25.0 kg/m2 predicted 33% and 29% BF in women and 23% and 20% BF in men and BMI of 27.5 kg/m2 predicted 35% and 31% BF in women and 26% and 22% BF in men, at the start and end of BCT, respectively. Sensitivity and specificity of BMI-based classification of %BF were poor. Soldiers below BMI of 20 kg/m2 had normal instead of markedly reduced %BF, reflecting especially low FFMI.

CONCLUSIONS

BCT alters the BMI-%BF relationship, with lower %BF at a given BMI by the end of BCT compared with the beginning, highlighting the unreliability of BMI to try to estimate body composition. The specific BMI threshold of 25.0 kg/m2, defined as 'overweight', is an out-of-date metric for health and performance outcomes. To the extent that %BF reflects physical readiness, these data provide evidence of a fit and capable military force at BMI greater than 25.0 kg/m2.

Body composition changes during 8 weeks of military training are not accurately captured by circumference-based assessments

In 1981, the US military adopted body fat standards to promote physical readiness and prevent obesity. Separate circumference-based equations were developed for women and men. Both predictive equations were known to underestimate %BF. However, it was not known how well these abdominal circumference-based methods tracked changes in %BF. This study examined the validity of the circumference-based %BF equations for assessing changes in %BF in young adult recruits during Army Basic Combat Training (BCT). Dual-energy X-ray absorptiometry (DXA) and circumference-based measures of %BF were obtained in women (n = 481) and men (n = 926) at the start (pre-BCT) and end (post-BCT) of 8 weeks of BCT. Repeated-measure ANOVAs were used to assess differences between DXA and circumference pre-BCT and for the change during BCT. Pre-BCT, circumferences underestimated %BF relative to DXA, with mean errors of -6.0% ± 4.4% for women and -6.0% ± 3.5% for men (both p < 0.01), and no difference between sexes was observed (p = 0.77). DXA detected a -4.0% ± 2.4% and -3.3% ± 2.8% change in %BF for women and men in response to BCT, respectively (both p < 0.01), whereas circumference estimates of %BF indicated a 0.0% ± 3.3% (p = 0.86) change in women and a -2.2% ± 3.3% (p < 0.01) change in men (sex difference by technique p < 0.01). In conclusion, circumference-based measures underestimated %BF at the start of BCT in both sexes as compared to DXA. Circumference measures underestimated changes in %BF during BCT in men and did not detect changes in women. These findings suggest that circumference-based %BF metrics may not be an appropriate tool to track changes in body composition during short duration training.

Methods to visualise zinc transporter proteins of the SLC39A family in cells

Zinc is essential to many important biological processes and the SLC39A family of zinc transporters which help to control zinc levels in cells, are increasingly being implicated in disease states. In order to determine their exact roles in these processes, reliable methods for their successful production are now required. Unfortunately, extensive post-translational modification and temporally specific activation makes visualisation of ZIP family transporters difficult. As such, modifications of common molecular cell biology techniques are necessary to maximise success when studying these proteins. These include zinc stimulation and nocodazole synchronisation to enhance the activation of ZIP7 and ZIP6/ZIP10, respectively. Maximal ZIP6/ZIP10 retention can also be achieved through careful handling of loosely adhered mitotic fractions when harvesting cell cultures for lysis. Transfection can also be used to enhance ZIP visualisation, however consideration of transfection periods and inclusion of sodium butyrate are recommended to enhance transfection efficiency. When probing for ZIP family transporters, we recommend that epitope choice considers post-translational cleavage and phosphorylated protein isoforms. Finally, where expression of a particular ZIP transporter is manipulated, researchers should consider parallel evaluation of related ZIP transporter expression, to account for transporter compensation.

Substance use and posttraumatic stress disorder: 12-month outcomes among adults experiencing chronic homelessness in Australia

INTRODUCTION

Substance use disorder and posttraumatic stress disorder (PTSD) are highly prevalent among individuals who experience homelessness. However, evaluations of interventions that combine housing and mental health services have reported inconsistent mental health and substance use outcomes when compared to usual services. We investigated 12-month change in substance use severity and PTSD symptom severity among adults experiencing chronic homelessness and tested whether observed differences were associated with housing, support from mental health services or the Journey to Social Inclusion (J2SI) program.

METHODS

A randomised controlled trial compared the J2SI program with standard service provision (N = 135). Secondary analyses compared those who obtained housing or received mental health services with those who did not. Primary outcomes were alcohol and illicit substance use severity (alcohol, smoking and substance involvement screening test) and PTSD symptom severity (six-item PTSD checklist).

RESULTS

There was significant improvement at 12 months in alcohol use severity, illicit substance use severity and PTSD symptoms in the overall sample. Having seen a mental health professional in the previous 12 months was associated with a significant reduction in alcohol and illicit substance use severity but was not associated with changes in PTSD symptom severity. Being housed at 12 months was associated with significantly higher alcohol use severity.

DISCUSSION AND CONCLUSIONS

Findings highlight the importance of access to mental health care for people with a history of chronic homelessness. Research is needed to develop and test therapeutic and housing approaches to reduce PTSD symptom severity among people with experience of homelessness.

Psychosis Early Intervention Across the Life Span: A Service Perspective

Previously youth-orientated, UK early intervention in psychosis (EI) services expanded care in 2016 to adults of any age. To compare EI care offering, clinical characteristics, and potential benefits for under-35s and over-35s, an observational study considering anonymised data for users of London-based EI services between April 2016 and December 2019 was conducted. Descriptive statistics and between groups comparisons are reported. The analysis considered 692 service users (32.5% over-35). Over-35s were more likely to be female, of poorer physical health, with severer problems at intake (Health of the Nation Outcome Scale, HoNOS). Under-35s had poorer appointment attendance, required increased use of inpatient facilities, and demonstrated greater risks to themselves and others. At discharge, HoNOS ratings indicated improvements for both groups. Over-35s constitute a considerable proportion of EI service-users, their care may involve less crisis management, more recovery-oriented intervention and physical health needs consideration. Care offering should reflect these needs.

The LIV-1 Subfamily of Zinc Transporters: From Origins to Present Day Discoveries

This review explains the origin of the LIV-1 family of zinc transporters, paying attention to how this family of nine human proteins was originally discovered. Structural and functional differences between these nine human LIV-1 family members and the five other ZIP transporters are examined. These differences are both related to aspects of the protein sequence, the conservation of important motifs and to the effect this may have on their overall function. The LIV-1 family are dependent on various post-translational modifications, such as phosphorylation and cleavage, which play an important role in their ability to transport zinc. These modifications and their implications are discussed in detail. Some of these proteins have been implicated in cancer which is examined. Furthermore, some additional areas of potential fruitful discovery are discussed and suggested as worthy of examination in the future.

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.

Body mass index, but not sex, influences exertional heat stroke risk in young healthy men and women

Exertional heat stroke (EHS) remains a persistent threat for individuals working or playing in the heat, including athletes and military and emergency service personnel. However, influence of biological sex and/or body mass index (BMI) on the risk of EHS remain poorly understood. The purpose of this study was to retrospectively assess the influence of sex and BMI on risk of EHS in the active-duty US Army. We analyzed data from 2016 to 2021, using a matched case-control approach, where each individual with a diagnosis of EHS was matched to five controls based on calendar time, unit ID, and job category, to capture control individuals who were matched to EHS events by location, time, and activity. We used a multivariate logistic regression model mutually adjusted for sex, BMI, and age to compare 745 (n = 61 F) individuals (26 ± 7 yr) with a diagnosed EHS to 4,290 (n = 384 F) case controls (25 ± 5 yr). Group average BMI were similar: 26.6 ± 3.1 (EHS) and 26.5 ± 3.6 kg/m² (CON). BMI was significantly (P < 0.0001) associated with higher risk of EHS with a 3% increase in risk of EHS for every unit increase in BMI. Notably, sex was not associated with any difference in risk for EHS (P = 0.54). These data suggest that young healthy people with higher BMI have significantly higher risk of EHS, but, contrary to what some have proposed, this risk was not higher in young women.

Behavioral couples therapy for brain injury: single case methodology with bi-phasic design

OBJECTIVES

To explore the outcomes of Behavioral Couples Therapy (BCT) for couples with brain injury.

BACKGROUND

Brain injury can result in communication, emotional and behavioral disturbances, leading to higher levels of depression, anxiety and relationship distress. Currently, no study has explored the outcomes of BCT in couples impacted by brain injury.

METHOD

Four heterosexual couples living with brain injury were seen at a specialist outpatient service, and attended an average of 13 (range 8-25) BCT sessions. Participants with brain injury and their partners completed weekly measures of depression, anxiety, and couple satisfaction throughout baseline, assessment, intervention, and follow-up phases. Data were visually analyzed, and effects examined using reliable change analysis, and between-phase comparison conducted using Tau-U.

RESULTS

Tau-U analysis demonstrated that both the patient and partner groups experienced significant overall improvement in relationship satisfaction and anxiety. Partners also reported significant reduction in depression scores overall. Reliable change analysis indicated improvement for some individual patients and partners, with effects maintained at follow-up in some cases.

CONCLUSIONS

The results offer promising results regarding the use of BCT for brain injury in increasing relationship satisfaction and reducing psychological distress. Further investigation is warranted.

A novel smartphone-based intervention targeting sleep difficulties in individuals experiencing psychosis: A feasibility and acceptability evaluation

OBJECTIVES

Cognitive Behavioural Therapy (CBT) is an effective psychological intervention for sleep difficulties and has been used successfully in individuals with psychosis. However, access is restricted due to lack of resources and staff training. Delivering CBT for sleep problems using smartphone technology may facilitate wider access. This study aimed to evaluate the feasibility, acceptability and potential usefulness of a guided, smartphone-based CBT intervention targeting sleep disturbance for individuals with psychosis.

DESIGN

Participants with psychosis spectrum diagnoses were recruited to a single-arm, uncontrolled study and engaged with the seven-module programme via smartphone app for six weeks with therapist support.

METHOD

Feasibility was assessed by rates of referral, recruitment and completion. Acceptability was assessed by app usage, a satisfaction questionnaire and qualitative analysis of participants' semi-structured interview. Pre- and post-intervention assessment of sleep, psychotic experiences, mood, well-being and functioning was conducted. Mean change confidence intervals were calculated and reported as an indication of usefulness.

RESULTS

Fourteen individuals consented to participation, and eleven completed the post-intervention assessment. On average, each participant engaged with 5.6 of 7 available modules. Qualitative feedback indicated the intervention was considered helpful and would be recommended to others. Suggested improvements to app design were provided by participants. Potential treatment benefits were observed for sleep difficulties, and all outcomes considered, except frequency of hallucinatory experiences.

CONCLUSIONS

It is feasible and acceptable to deliver therapist-guided CBT for sleep problems by smartphone app for individuals with psychosis. This method provides a low-intensity, accessible intervention, which could be offered more routinely. Further research to determine treatment efficacy is warranted.

Timing of stress fracture in soldiers during the first 6 career months: a retrospective cohort study

CONTEXT

Stress fractures (SF) are injuries that can result from beginning new or higher volume physical training regimens. The pattern of clinical presentation of SF over time after individuals start a new or more demanding physical training regimen is not well defined in medical literature.

OBJECTIVE

Report trends in the clinical presentation of stress fractures over the first six month of soldiers' time in the service.

DESIGN

Retrospective Cohort study Setting: This study was conducted using medical encounter and personnel data from U.S. Army soldiers during the first 6 months of their career.

PARTICIPANTS

U.S. Army soldiers beginning their careers from 2005-2014 (N=701,027).

DATA COLLECTION AND ANALYSIS

Weekly SF numbers and incidence were calculated overall, as well as by sex, over the first 6 months of military service.

RESULTS

SF diagnoses (N=14,155) increased steeply in weeks 3 and 4, with a peak in the overall incidence of SF diagnoses occurring during weeks 5-8. Although clinical incidence of stress fracture generally decreased beyond 8 weeks, incident lower extremity stress fractures continued to present for over 20 weeks. The hazard ratio (HR) for SF among women compared to men was 4.14 (95% CI = [4.01, 4.27]).

CONCLUSIONS

Across the 6-month study period, women showed over 4 times greater hazard for stress fracture. The results also suggest that health care providers should be particularly vigilant for stress fractures within 3 weeks after the beginning of a new or higher intensity exercise regimen. The incidence of SF may continue to climb for several weeks. Even as stress fracture incidence declines, it should be noted that these injuries may also continue to appear clinically even several months after a change in activity or training.

Quantifying Training Load During Physically Demanding Tasks in U.S. Army Soldiers: A Comparison of Physiological and Psychological Measurements

INTRODUCTION

There are many ways to quantify the training loads required to perform soldiering tasks. Although indirect calorimetry may provide the most accurate measures, the equipment can be burdensome and expensive. Simpler measures may provide sufficient data, while being more practical for measuring soldiers in the field. The purpose of this study was to examine the relationship between total relative oxygen uptake (TotalRelVO2) measured by indirect calorimetry during three soldiering tasks, with two field-expedient measures of training load: summated heart rate zone (sumHR) and session rate of perceived exertion (sRPE).

MATERIALS AND METHODS

33 male and 28 female soldiers performed three soldiering tasks while wearing a 32.3-kg fighting load: sandbag fill, sandbag carry, and ammunition can carry. Metabolic measurements were monitored and completion times were recorded (min). TotalRelVO2 (average relative VO2*time) and age-predicted maximal heart rate (220-age) were calculated. SumHR was calculated by multiplying time spent in each of the five heart rate zones by a multiplier factor for each zone (50-59% = 1, 60-69% = 2, 70-79% = 3, 80-89% = 4, and ≥90% = 5). RPE (Borg 6-20 scale) was collected at the end of each task, then sRPE was calculated (RPE*time). Pearson and Spearman correlations were performed to examine the relationship between TotalRelVO2, sumHR and sRPE. Wilcoxon signed rank tests were conducted to determine if there was a difference in median rankings between the three variables for each task. Linear regressions were performed to determine predictability of TotalRelVO2 from sumHR and sRPE. The study was approved by the U.S. Army Research Institute of Environmental Medicine Institutional Review Board.

RESULTS

Significant, positive correlations were revealed for all three tasks between TotalRelVO2, sumHR and sRPE (r ≥ 0.67, p ≤ 0.01; rho≥0.74, p ≤ 0.01). Wilcoxon signed rank tests revealed no significant differences in rankings between TotalRelVO2, sumHR and sRPE for all three tasks (p ≥ 0.43). Both sumHR and sRPE are significant predictors of TotalRelVO2 (p ≤ 0.01).

CONCLUSIONS

SumHR and sRPE are acceptable alternatives to TotalRelVO2 when attempting to quantify and/or monitor training load during soldiering tasks.

Comparison of Different Variants of the U.S. Army Occupational Physical Assessment Test

INTRODUCTION

The U.S. Army Occupational Physical Assessment Test (OPAT) is a pre-enlistment physical employment screening assessment developed to place recruits and soldiers into Military Occupational Specialties (MOSs) based on their physical capabilities in order to optimize performance and limit injury. The OPAT consists of the seated power throw (SPT), strength deadlift (SDL), standing long jump, and interval aerobic run. During the scientific validation of the OPAT, two variants of the SPT and two variants of the SDL were used. Although the OPAT was validated using both variants for each test, U.S. Army scientists and policymakers have received queries regarding how these variants compare to each other. Therefore, the purpose of this study was to compare different variants of the SPT and SDL.

MATERIALS AND METHODS

Thirty-two participants (14 male and 18 female) between the ages of 18 and 42 years visited the laboratory on one occasion and performed two variants of the SPT (seated on the ground [the current OPAT standard] versus seated in a chair with a 35 cm seat height) and two variants of the SDL (using a hex-bar [the current OPAT standard] versus using paired dumbbells). Testing order for the different variants was randomized. The protocol was approved by the U.S. Army Medical Research and Development Command Institutional Review Board.

RESULTS

Performing the SPT from a chair significantly (P < .05) increased performance when compared to performing the SPT from the ground (5.4 ± 1.3 m versus 5.0 ± 1.4 m, respectively). Values for the two SPT variants were correlated (tau = 0.90). Performing the SDL using the hex-bar significantly increased the maximal weight lifted when compared to performing the SDL using paired dumbbells (86.9 ± 18.4 kg versus 83.1 ± 18.0 kg, respectively). Values for the two SDL variants were correlated (tau = 0.83).

CONCLUSIONS

Performing different variants of the SPT and SDL influenced the resulting score. Although these findings do not alter the administration or scoring of the OPAT, they do provide a valuable reference in the event of future inquiries regarding the development of the OPAT.

Zinc transporters and their functional integration in mammalian cells

Zinc is a ubiquitous biological metal in all living organisms. The spatiotemporal zinc dynamics in cells provide crucial cellular signaling opportunities, but also challenges for intracellular zinc homeostasis with broad disease implications. Zinc transporters play a central role in regulating cellular zinc balance and subcellular zinc distributions. The discoveries of two complementary families of mammalian zinc transporters (ZnTs and ZIPs) in the mid-1990s spurred much speculation on their metal selectivity and cellular functions. After two decades of research, we have arrived at a biochemical description of zinc transport. However, in vitro functions are fundamentally different from those in living cells, where mammalian zinc transporters are directed to specific subcellular locations, engaged in dedicated macromolecular machineries, and connected with diverse cellular processes. Hence, the molecular functions of individual zinc transporters are reshaped and deeply integrated in cells to promote the utilization of zinc chemistry to perform enzymatic reactions, tune cellular responsiveness to pathophysiologic signals, and safeguard cellular homeostasis. At present, the underlying mechanisms driving the functional integration of mammalian zinc transporters are largely unknown. This knowledge gap has motivated a shift of the research focus from in vitro studies of purified zinc transporters to in cell studies of mammalian zinc transporters in the context of their subcellular locations and protein interactions. In this review, we will outline how knowledge of zinc transporters has been accumulated from in-test-tube to in-cell studies, highlighting new insights and paradigm shifts in our understanding of the molecular and cellular basis of mammalian zinc transporter functions.

Characterization of Limited Duty Neuromusculoskeletal Injuries and Return to Duty Times in the U.S. Army During 2017-2018

INTRODUCTION

Neuromusculoskeletal injuries (MSKI) are the leading cause of medical encounters, lost or limited duty days, medical evacuations, and disability in the U.S. Army. In the U.S. Army, objective MSKI incidence rate metrics can be determined through medical encounter data (M2SKIs) with International Classification of Diseases (ICD) 9 and ICD 10 codes or through documented limited duty profiles (LDPs) documenting time-loss MSKI (TLMSKI). The purpose of the current study was to characterize the population incidence of TLMSKIs among U.S. Army soldiers.

MATERIALS AND METHODS

This study was approved by the Medical Research and Development Command's Institutional Review Board. This was a retrospective population-level study. The U.S. Army's eProfile system was utilized to characterize all LDPs issued during 2017-2018 and to describe the body regions injured and activities associated with these TLMSKIs.

RESULTS

The incidence rate of TLMSKIs was found to be 44 and 40 TLMSKI/100 soldier-years for 2017 and 2018, respectively, which is lower than previously published incidence rates using MSKI receiving medical care. Approximately one quarter of the total active duty Army population in 2017 and 2018 recorded limited duty injuries, where those to the ankle/foot region resulted in the most LDPs and those to the knee resulted in the most lost duty days. The majority of all TLMSKIs were associated with fitness training-related activities.

CONCLUSION

This descriptive study is the first to present the U.S. Army population rates for MSKIs that result in LDPs, representing key time losses when soldiers cannot participate in their military occupational and physical training tasks. This study utilizes the LDP system to calculate limited duty days instead of attempting to estimate this information from other means. The eProfile system is limited in that it combines body regions such as ankle/foot and does not allow isolation of ankle or foot independently. It is recommended that research and training programs target the identification, development, and validation of effective and scaleable strategies to maximize performance without severely reducing combat effectiveness because of training TLMSKIs.

Sleep health of incoming army trainees and how it changes during basic combat training

OBJECTIVE

To examine the sleep health of incoming Army trainees and how it is impacted during basic combat training (BCT).

DESIGN

Prospective.

SETTING

BCT site (Fort Jackson, SC).

PARTICIPANTS

A total of 1349 trainees (936 = male, 413 = female, 20.73 ± 3.67 years).

MEASUREMENTS

Participants completed the Pittsburgh Sleep Quality Index (PSQI), the Morningness/Eveningness Questionnaire, and the Epworth Sleepiness Scale at the start of BCT and a modified PSQI at the end of BCT.

RESULTS

At baseline, trainees reported an average sleep duration of 7.65 ± 1.68 hours per night, with 81.8% rating their sleep quality as "Very Good or Fairly Good." The mean reported Morningness/Eveningness Questionnaire score was 50.63 ± 8.11 and the mean Epworth Sleepiness Scale was 8.60 ± 4.02. Reported sleep duration was significantly less during BCT (6.73 ± 0.90 hours) compared to baseline (P< .001). There was no significant difference in the mean PSQI Global score at the end of BCT compared to the start (5.33 ± 3.00 vs. 5.42 ± 2.85, P = .440), however, 6 of the 7 component scores were significantly different (with Sleep Quality, Sleep Duration, and Daytime Dysfunction scores being higher/worse and Sleep Latency, Sleep Efficiency, and Sleep Medication Use scores being lower/improved [all P < .01]).

CONCLUSIONS

Army BCT trainees in this large sample reported good sleep health characteristics at entry to training, including achieving recommended sleep amounts (>7 hours per night) and reporting good sleep quality. During BCT, negative changes were observed in reported sleep duration and quality in trainees. Further investigation into the factors contributing to changes in trainees' sleep health during BCT and the implications on subsequent readiness, injury risk, and performance is warranted.

Effect of Environmental Temperature and Humidity on Permethrin Biomarkers of Exposure in U.S. Soldiers Wearing Permethrin-Treated Uniforms

Environmental factors, including high temperature and humidity, can influence dermal absorption of chemicals. Soldiers can be dermally exposed to permethrin while wearing permethrin-treated uniforms. This study aimed at examining the effects of high temperature and a combined high temperature and humid environment on permethrin absorption compared with ambient conditions when wearing a permethrin-treated uniform. Twenty-seven male enlisted soldiers wore study-issued permethrin-treated army uniforms for 33 consecutive hours in three different environments: 1) simulated high temperature (35°C, 40% relative humidity [rh]) (n = 10), 2) simulated high temperature and humidity (30°C, 70% rh) (n = 10), and 3) ambient conditions (13°C, 60% rh) (n = 7). Spot urine samples, collected at 21 scheduled time points before, during, and after wearing the study uniforms, were analyzed for permethrin exposure biomarkers (3-phenoxybenzoic acid, cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid) and creatinine. Biomarker concentrations were 60-90% higher in the heat and combined heat/humidity groups (P < 0.001-0.022) than the ambient group. Also, the average daily permethrin dose, calculated 12 hours after removing the treated uniforms, was significantly higher in the heat (P = 0.01) and the heat/humidity (P = 0.03) groups than the ambient group. There were no significant differences in biomarker concentrations or computed average daily dose between the heat and the heat/humidity groups. Both hot and combined hot and humid environmental conditions significantly increased permethrin absorption in soldiers wearing permethrin-treated uniforms.

The ZIP6/ZIP10 heteromer is essential for the zinc-mediated trigger of mitosis

Zinc has been known to be essential for cell division for over 40 years but the molecular pathways involved remain elusive. Cellular zinc import across biological membranes necessitates the help of zinc transporters such as the SLC39A family of ZIP transporters. We have discovered a molecular process that explains why zinc is required for cell division, involving two highly regulated zinc transporters, as a heteromer of ZIP6 and ZIP10, providing the means of cellular zinc entry at a specific time of the cell cycle that initiates a pathway resulting in the onset of mitosis. Crucially, when the zinc influx across this heteromer is blocked by ZIP6 or ZIP10 specific antibodies, there is no evidence of mitosis, confirming the requirement for zinc influx as a trigger of mitosis. The zinc that influxes into cells to trigger mitosis additionally changes the phosphorylation state of STAT3 converting it from a transcription factor to a protein that complexes with this heteromer and pS³⁸Stathmin, the form allowing microtubule rearrangement as required in mitosis. This discovery now explains the specific cellular role of ZIP6 and ZIP10 and how they have special importance in the mitosis process compared to other ZIP transporter family members. This finding offers new therapeutic opportunities for inhibition of cell division in the many proliferative diseases that exist, such as cancer.

Permethrin exposure from wearing fabric-treated military uniforms in high heat conditions under varying wear-time scenarios

This study examined the effect of high-temperature conditions and uniform wear time durations (expeditionary, 33 h continuous wear; garrison, 3 days, 8 h/day wear) on permethrin exposure, assessed by urinary permethrin biomarkers, from wearing post-tailored, factory-treated military uniforms. Four group study sessions took place over separate 11-day periods, involving 33 male Soldiers. Group 1 (n = 10) and Group 2 (n = 8) participants wore a study-issued permethrin-treated Army uniform under high heat environment (35 °C, 40% relative humidity (rh)) and expeditionary and garrison wear-time conditions, respectively. For comparison, Group 3 (n = 7) and Group 4 (n = 8) participants wore study-issued permethrin-treated uniforms in cooler ambient conditions under operational and garrison wear-time conditions, respectively. Urinary biomarkers of permethrin (3-phenoxybenzoic acid, and the sum of cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid) were significantly higher under high temperature compared to ambient conditions, regardless of wear-time situations (Group 1 vs. Group 3; Group 2 vs. Group 4; p < 0.001, for both). Under high-temperature conditions, expeditionary (continuous) compared to garrison wear-time resulted in significantly (p < 0.001) higher urinary biomarker concentrations (Group 1 vs. Group 2). Differences related to wear-time under the ambient conditions (Group 3 vs. Group 4) were not statistically significant. Findings suggest that wearing permethrin-treated clothing in heat conditions results in higher internal dose of permethrin above that observed under ambient conditions.

Detailed analyses of the crucial functions of Zn transporter proteins in alkaline phosphatase activation

Numerous zinc ectoenzymes are metalated by zinc and activated in the compartments of the early secretory pathway before reaching their destination. Zn transporter (ZNT) proteins located in these compartments are essential for ectoenzyme activation. We have previously reported that ZNT proteins, specifically ZNT5-ZNT6 heterodimers and ZNT7 homodimers, play critical roles in the activation of zinc ectoenzymes, such as alkaline phosphatases (ALPs), by mobilizing cytosolic zinc into these compartments. However, this process remains incompletely understood. Here, using genetically-engineered chicken DT40 cells, we first determined that Zrt/Irt-like protein (ZIP) transporters that are localized to the compartments of the early secretory pathway play only a minor role in the ALP activation process. These transporters included ZIP7, ZIP9, and ZIP13, performing pivotal functions in maintaining cellular homeostasis by effluxing zinc out of the compartments. Next, using purified ALP proteins, we showed that zinc metalation on ALP produced in DT40 cells lacking ZNT5-ZNT6 heterodimers and ZNT7 homodimers is impaired. Finally, by genetically disrupting both ZNT5 and ZNT7 in human HAP1 cells, we directly demonstrated that the tissue-nonspecific ALP-activating functions of both ZNT complexes are conserved in human cells. Furthermore, using mutant HAP1 cells, we uncovered a previously-unrecognized and unique spatial regulation of ZNT5-ZNT6 heterodimer formation, wherein ZNT5 recruits ZNT6 to the Golgi apparatus to form the heterodimeric complex. These findings fill in major gaps in our understanding of the molecular mechanisms underlying zinc ectoenzyme activation in the compartments of the early secretory pathway.

Cognitive Behavioural Therapy for Nightmares for Patients with Persecutory Delusions (Nites): An Assessor-Blind, Pilot Randomized Controlled Trial

OBJECTIVE

Nightmares are relatively common in patients experiencing psychosis but rarely assessed or treated. Nightmares may maintain persecutory delusions by portraying fears in sensory-rich detail. We tested the potential benefits of imagery-focused cognitive behavioural therapy (CBT) for nightmares on nightmare severity and persecutory delusions.

METHOD

This assessor-blind parallel-group pilot trial randomized 24 participants with nightmares and persecutory delusions to receive CBT for nightmares delivered over 4 weeks in addition to treatment as usual (TAU) or TAU alone. Assessments were at 0, 4 (end of treatment), and 8 weeks (follow-up). Feasibility outcomes assessed therapy uptake, techniques used, satisfaction, and attrition. The primary efficacy outcome assessed nightmare severity at week 4. Analyses were intention to treat, estimating treatment effect with 95% confidence intervals (CIs).

RESULTS

All participants offered CBT completed therapy (mean [SD], 4.8 [0.6] sessions) with high satisfaction, and 20 (83%) participants completed all assessments. Compared with TAU, CBT led to large improvements in nightmares (adjusted mean difference = -7.0; 95% CI, -12.6 to -1.3; d = -1.1) and insomnia (6.3; 95% CI, 2.6 to 10.0; d = 1.4) at week 4. Gains were maintained at follow-up. Suicidal ideation was not exacerbated by CBT but remained stable to follow-up, compared with TAU, which reduced at follow-up (6.8; 95% CI, 0.3 to 3.3; d = 0.7). CBT led to reductions in paranoia (-20.8; 95% CI, -43.2 to 1.7; d = -0.6), although CIs were wide. Three serious adverse events were deemed unrelated to participation (CBT = 2, TAU = 1).

CONCLUSIONS

CBT for nightmares is feasible and may be efficacious for treating nightmares and comorbid insomnia for patients with persecutory delusions. It shows promise on paranoia but potentially not on suicidal ideation.

The comments of voices on the appearance of patients with psychosis: 'the voices tell me that I am ugly'

BACKGROUND

There are high rates of obesity and low self-esteem in patients with psychosis. The occurrence of negative voice content directly about appearance is therefore plausible. Derogatory comments about appearance are likely to be distressing, increase depression and contribute to social withdrawal.

AIMS

To systematically assess the occurrence of voice content regarding appearance and identify correlates.

METHOD

Sixty patients experiencing verbal auditory hallucinations at least once a week in the context of non-affective psychosis completed a measure assessing positive and negative voice content about appearance. They also completed assessments about body image, self-esteem, psychiatric symptoms and well-being.

RESULTS

Fifty-five (91.7%) participants reported hearing voices comment on their appearance. A total of 54 (90%) patients reported negative voice content about their appearance with 30 (50%) patients experienced negative appearance comments on a daily basis. The most common negative comment was 'the voices tell me that I am ugly' (n = 48, 80%). There were 39 (65%) patients who reported positive voice content on appearance. The most frequent positive comment was 'I look as nice as other people' (n = 26, 43.3%). Negative voice content about appearance was associated with body image concerns, paranoia, voice hearing severity, depression, worry, negative self-beliefs and safety-seeking behaviours. Positive appearance voice content was associated with greater body esteem and well-being and lower levels of depression and insomnia.

CONCLUSIONS

Voice content about appearance is very common for patients seen in clinical services. Negative voice content may reflect - and subsequently reinforce - negative beliefs about one's appearance, low self-esteem, worry and paranoia.

DECLARATION OF INTEREST

None.

The weeks before 100 persecutory delusions: the presence of many potential contributory causal factors

BACKGROUND

The period before the formation of a persecutory delusion may provide causal insights. Patient accounts are invaluable in informing this understanding.

AIMS

To inform the understanding of delusion formation, we asked patients about the occurrence of potential causal factors - identified from a cognitive model - before delusion onset.

METHOD

A total of 100 patients with persecutory delusions completed a checklist about their subjective experiences in the weeks before belief onset. The checklist included items concerning worry, images, low self-esteem, poor sleep, mood dysregulation, dissociation, manic-type symptoms, aberrant salience, hallucinations, substance use and stressors. Time to reach certainty in the delusion was also assessed.

RESULTS

Most commonly it took patients several months to reach delusion certainty (n = 30), although other patients took a few weeks (n = 24), years (n = 21), knew instantly (n = 17) or took a few days (n = 6). The most frequent experiences occurring before delusion onset were: low self-confidence (n = 84); excessive worry (n = 80); not feeling like normal self (n = 77); difficulties concentrating (n = 77); going over problems again and again (n = 75); being very negative about the self (n = 75); images of bad things happening (n = 75); and sleep problems (n = 75). The average number of experiences occurring was high (mean 23.5, s.d. = 8.7). The experiences clustered into six main types, with patients reporting an average of 5.4 (s.d. = 1.0) different types.

CONCLUSIONS

Patients report numerous different experiences in the period before full persecutory delusion onset that could be contributory causal factors, consistent with a complex multifactorial view of delusion occurrence. This study, however, relied on retrospective self-report and could not determine causality.

DECLARATION OF INTEREST

None.

Treatable clinical intervention targets for patients with schizophrenia

BACKGROUND

Treatment approaches for patients with psychosis need major improvement. Our approach to improvement is twofold: target putative causal mechanisms for psychotic experiences that are treatable and also that patients wish treated. This leads to greater treatment engagement and clinical benefit. To inform mental health service provision we assessed the presence of treatable causal mechanisms and patient treatment preferences.

METHODS

Patients with non-affective psychosis attending NHS mental health services completed assessments of paranoia, hallucinations, anxious avoidance, worry, self-esteem, insomnia, analytic reasoning, psychological well-being, and treatment preferences.

RESULTS

1809 patients participated. Severe paranoia was present in 53.4% and frequent voices in 48.2%. Of the causal mechanisms, severe worry was present in 67.7%, avoidance at agoraphobic levels in 64.5%, analytic reasoning difficulties in 55.9%, insomnia in 50.1%, poor psychological well-being in 44.3%, strongly negative self-beliefs in 36.6%, and weak positive self-beliefs in 19.2%. Treatment target preferences were: feeling happier (63.2%), worrying less (63.1%), increasing self-confidence (62.1%), increasing activities (59.6%), improving decision-making (56.5%), feeling safer (53.0%), sleeping better (52.3%), and coping with voices (45.3%). Patients with current paranoia and/or hallucinations had higher levels of the causal factors and of wanting these difficulties treated.

CONCLUSIONS

Patients with non-affective psychosis have high levels of treatable problems such as agoraphobic avoidance, worry, low self-esteem, and insomnia and they would like these difficulties treated. Successful treatment of these difficulties is also likely to decrease psychotic experiences such as paranoia.

Activated zinc transporter ZIP7 as an indicator of anti-hormone resistance in breast cancer

ZIP7, a member of the ZIP family of zinc importers, resides on the endoplasmic reticulum membrane and transports zinc from intracellular stores to the cytoplasm after activation by CK2 phosphorylation on two serine residues (S275 and S276). ZIP7 is known to be required for the growth of anti-hormone resistant breast cancer models, especially those with acquired tamoxifen resistance developed from MCF-7. Using our new pS275S276ZIP7 antibody which only recognises activated ZIP7 (pZIP7), we have demonstrated that the hyperactivation of ZIP7 is prevalent in tamoxifen-resistant breast cancer cells. This evidence suggests that pZIP7 might have potential as a biomarker of acquired resistance to such anti-hormones in breast cancer, a current unmet clinical need. In this regard, we have also developed a new immunohistochemical assay for pZIP7 which allowed pZIP7 to be tested on a small clinical series of breast cancer tissues confirming its prevalence in such tumours and relationship to a variety of clinicopathological parameters and biomarkers previously associated with endocrine resistant phenotypes, notably increased activated MAPK signalling, expression of ErbB2, CD71 and the proto-oncogene c-Fos, as well as with increased tumour grade.

Suicidal ideation and behaviour in patients with persecutory delusions: Prevalence, symptom associations, and psychological correlates

BACKGROUND

To determine the prevalence of suicidal ideation and behaviour - and their correlates - in patients with persecutory delusions.

METHODS

110 patients with persecutory delusions in the context of non-affective psychosis were assessed for suicidal thoughts and behaviours over the past month. Symptom and psychological assessments were also completed.

RESULTS

The severity of suicidal ideation was: no suicidal ideation (n = 26, 23.6%); wish to be dead (n = 21, 19.1%); nonspecific active suicidal thoughts (n = 14, 12.7%); suicidal thoughts with methods but no intent (n = 29, 26.4%); suicidal thoughts with intent but no specific plan (n = 13, 11.8%); and suicidal intent with plan (n = 7, 6.4%). In the past month, five patients (4.5%) had made an actual, interrupted, or aborted suicide attempt. The severity of suicidal ideation was associated with higher levels of depression, paranoia, hallucinations, anger, insomnia, negative beliefs about the self and others, pessimism, worry, and delusion safety-seeking behaviours and lower levels of psychological well-being and reward responsiveness. Severity of ideation was not associated with cannabis or alcohol use, working memory, pain, or meaningful activity levels.

CONCLUSIONS

Patients with persecutory delusions are typically in a severe state of psychological stress, and at risk of suicide, as indicated by very high levels of suicidal ideation. This exploratory study also identifies correlates of suicidal ideation that could be investigated in causal research designs.

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.

ZnR/GPR39 upregulation of K+/Cl--cotransporter 3 in tamoxifen resistant breast cancer cells

Expression of the zinc receptor, ZnR/GPR39, is increased in higher grade breast cancer tumors and cells. Zinc, its ligand, is accumulated at larger concentrations in the tumor tissue and can therefore activate ZnR/GPR39-dependent Ca²⁺ signaling leading to tumor progression. The K⁺/Cl^- co-transporters (KCC), activated by intracellular signaling, enhance breast cancer cell migration and invasion. We asked if ZnR/GPR39 enhances breast cancer cell malignancy by activating KCC. Activation of ZnR/GPR39 by Zn²⁺ upregulated K⁺/Cl^- co-transport activity, measured using NH₄⁺ as a surrogate to K⁺ while monitoring intracellular pH. Upregulation of NH₄⁺ transport was monitored in tamoxifen resistant cells with functional ZnR/GPR39-dependent Ca²⁺ signaling but not in MCF-7 cells lacking this response. The NH₄⁺ transport was Na⁺-independent, and we therefore focused on KCC family members. Silencing of KCC3, but not KCC4, expression abolished Zn²⁺-dependent K⁺/Cl^- co-transport, suggesting that KCC3 is mediating upregulated NH₄⁺ transport. The ZnR/GPR39-dependent KCC3 activation accelerated scratch closure rate, which was abolished by inhibiting KCC transport with [(DihydroIndenyl) Oxy] Alkanoic acid (DIOA). Importantly, silencing of either ZnR/GPR39 or KCC3 attenuated Zn²⁺-dependent scratch closure. Thus, a novel link between KCC3 and Zn²⁺, via ZnR/GPR39, promotes breast cancer cell migration and proliferation.

A mixed methods randomised control trial to evaluate the effectiveness of the journey to social inclusion - phase 2 intervention for chronically homeless adults: study protocol

Background

Chronic homelessness is a problem characterised by longstanding inability to attain or maintain secure accommodation. Longitudinal research with homeless populations is challenging, and randomised controlled trials that evaluate the effectiveness of intensive, case management interventions aimed at improving housing and health-related outcomes for chronically homelessness people are scant. More research is needed to inform programmatic design and policy frameworks in this area. This study protocol details an evaluation of the Journey to Social Inclusion – Phase 2 program, an intervention designed to reduce homelessness and improve outcomes in chronically homeless adults.

Methods/design

J2SI Phase 2 is a three-year, mixed methods, multi-site, RCT that enrolled 186 participants aged 25 to 50 years between 07 January 2016 and 30 September 2016 in Melbourne. The intervention group (n = 90 recruited) receives the J2SI Phase 2 program, a trauma-informed intervention that integrates intensive case management and service coordination; transition to housing and support to sustain tenancy; and support to build social connections, obtain employment and foster independence. The comparison group (n = 96 recruited) receives standard service provision. Prior to randomisation, participants completed a baseline survey. Follow-up surveys will be completed every six months for three years (six in total). In addition to self-report data on history of homelessness and housing, physical and mental health, substance use, quality of life, social connectedness and public service utilisation, linked administrative data on participants’ public services utilisation (e.g., hospitalisation, justice system) will be obtained for the three-year period pre- and post-randomisation. Semi-structured, qualitative interviews will be conducted with a randomly selected subset of participants and service providers at three time-points to explore changes in key outcome variables and to examine individual experiences with the intervention and standard service provision. An economic evaluation of the intervention and associated costs will also be undertaken.

Discussion

Results of this trial will provide robust evidence on the effectiveness of J2SI Phase 2 compared to standard service provision. If the intervention demonstrates effectiveness in improving housing, health, quality-of-life, and other social outcomes, it may be considered for broader national and international dissemination to improve outcomes among chronically homeless adults.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12616000162415 (retrospectively registered 10-February-2016).

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6644-1) contains supplementary material, which is available to authorized users.

Nonsteroidal Anti-Inflammatory Drug Prescriptions Are Associated With Increased Stress Fracture Diagnosis in the US Army Population

Stress fractures are common in military personnel and endurance athletes, and nonsteroidal anti-inflammatory drug (NSAID) use is widespread in these populations. NSAIDs inhibit prostaglandin synthesis, which blunts the anabolic response of bone to physical activity and could therefore increase risk of stress fracture. The objective of this study was to determine whether prescribed NSAIDs were associated with stress fracture diagnoses among US Army soldiers. We also aimed to establish whether acetaminophen, an analgesic alternative to NSAIDs, was associated with stress fracture risk. A nested case-control study was conducted using data from the Total Army Injury and Health Outcomes Database from 2002 to 2011 (n = 1,260,168). We identified soldiers with a diagnosis of stress fracture (n = 24,146) and selected 4 controls per case matched on length of military service (n = 96,584). We identified NSAID and acetaminophen prescriptions 180 to 30 days before injury (or match date). We also identified soldiers who participated in basic combat training (BCT), a 10-week period of heightened physical activity at the onset of Army service. Among these individuals, we identified 9088 cases and 36,878 matched controls. Conditional logistic regression was used to calculate incident rate ratios (RR) for stress fracture with adjustment for sex. NSAID prescription was associated with a 2.9-fold increase (RR = 2.9, 95% confidence interval [CI] 2.8-2.9) and acetaminophen prescription with a 2.1-fold increase (RR = 2.1, 95% CI 2.0-2.2) in stress fracture risk within the total Army population. The risk was more than 5-fold greater in soldiers prescribed NSAIDs (RR = 5.3, 95% CI 4.9-5.7) and more than 4-fold greater in soldiers prescribed acetaminophen (RR = 4.4, 95% CI 3.9-4.9) during BCT. Our results reveal an association between NSAID and acetaminophen prescriptions and stress fracture risk, particularly during periods of heightened physical activity. Prospective observational studies and randomized controlled trials are needed to support these findings before clinical recommendations can be made. © 2018 American Society for Bone and Mineral Research.

Concussion History and Cognitive Function in a Large Cohort of Adolescent Athletes

BACKGROUND

The incidence of reported concussions in the adolescent population is increasing, yet research on the effects of concussions in this population is minimal and inconclusive.

PURPOSE

To assess the association between concussion and performance on a cognitive test battery.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Using multivariate models, the authors assessed the association between concussion and performance on a cognitive test battery among 5616 high school and junior high school athletes. The researchers utilized a global cognitive score and scores for 5 domains: verbal memory, visual memory, visual motor, reaction time, and impulse control. Each cognitive score was converted to a z score with the mean and SD of the nonconcussed population. Results from each model were then interpreted as change in the standardized unit score. In the models, concussion was evaluated as ever having a concussion, number of concussions, time since last concussion, and age at first concussion.

RESULTS

Ever having a concussion was associated with a mean decrease of 0.11 standardized units (95% CI, -0.20 to -0.01) on the global cognitive score and lower scores in all cognitive domains. Each additional concussion was associated with lower scores on global cognitive function (effect estimate, -0.06; 95% CI, -0.11 to -0.02), verbal memory, visual memory, and impulse control. Concussion in early childhood was associated with lower global cognition (effect estimate, -0.05; 95% CI, -0.08 to -0.01), visual memory, and motor visual scores as compared with concussions in later childhood. The associations between time since last concussion and cognitive test scores were nonlinear, and on all tests, lower scores were observed even ≥1 year after the concussion.

CONCLUSION

On the basis of objective performance metrics for cognitive function, concussions had a more persistent effect on cognitive function than previously thought. The age at which an individual has his or her first concussion may be an important factor in determining long-lasting cognitive effects.