Symptoms in 18,495 Persian Gulf War veterans. Latency of onset and lack of association with self-reported exposures

MMPI-2-RF Profiles of Treatment-Seeking Veterans in a VA Pain Clinic and Associations with Markers of Physical Performance

Chronic pain is a debilitating condition for many military Veterans and is associated with posttraumatic stress disorder (PTSD). This study examined the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) in 144 Veterans (88.2% male, mean age = 57.95 years) recruited from a VA outpatient pain clinic and associations with self-reported pain severity, pain-related interference in daily activities, prescription opioid use, and objective metrics of physical performance on tasks impacted by pain (walking, stair climbing, grip strength, indexed by a single latent variable). Among the cohort with valid responses on the MMPI-2-RF (n = 117) and probable PTSD, mean Somatic Complaints (RC1) and Ideas of Persecution (RC6) scores were clinically elevated. All MMPI-2-RF scales were more strongly correlated with self-reported pain interference than severity. Regressions revealed associations between self-rated pain interference (but not pain or PTSD severity) and physical performance scores (β = .36, p = .001). MMPI-2-RF overreporting Validity and Higher-Order scales contributed incremental variance in predicting physical performance, including Infrequent Psychopathology Responses (β = .33, p = .002). PTSD severity was associated with prescription opioid use when accounting for the effects of over-reported somatic and cognitive symptoms (odds ratio 1.05, p ≤ .025). Results highlight the role of symptom overreporting and perceptions of functional impairment to observable behaviors among individuals with chronic pain.

Is exposure to chemical pollutants associated with sleep outcomes? A systematic review

Environmental exposures may influence sleep; however, the contributions of environmental chemical pollutants to sleep health have not been systematically investigated. We conducted a systematic review to identify, evaluate, summarize, and synthesize the existing evidence between chemical pollutants (air pollution, exposures related to the Gulf War and other conflicts, endocrine disruptors, metals, pesticides, solvents) and dimensions of sleep health (architecture, duration, quality, timing) and disorders (sleeping pill use, insomnia, sleep-disordered breathing)). Of the 204 included studies, results were mixed; however, the synthesized evidence suggested associations between particulate matter, exposures related to the Gulf War, dioxin and dioxin-like compounds, and pesticide exposure with worse sleep quality; exposures related to the Gulf War, aluminum, and mercury with insomnia and impaired sleep maintenance; and associations between tobacco smoke exposure with insomnia and sleep-disordered breathing, particularly in pediatric populations. Possible mechanisms relate to cholinergic signaling, neurotransmission, and inflammation. Chemical pollutants are likely key determinants of sleep health and disorders. Future studies should aim to evaluate environmental exposures on sleep across the lifespan, with a particular focus on developmental windows and biological mechanisms, as well as in historically marginalized or excluded populations.

Mitochondrial impairment but not peripheral inflammation predicts greater Gulf War illness severity

Gulf War illness (GWI) is an important exemplar of environmentally-triggered chronic multisymptom illness, and a potential model for accelerated aging. Inflammation is the main hypothesized mechanism for GWI, with mitochondrial impairment also proposed. No study has directly assessed mitochondrial respiratory chain function (MRCF) on muscle biopsy in veterans with GWI (VGWI). We recruited 42 participants, half VGWI, with biopsy material successfully secured in 36. Impaired MRCF indexed by complex I and II oxidative phosphorylation with glucose as a fuel source (CI&CIIOXPHOS) related significantly or borderline significantly in the predicted direction to 17 of 20 symptoms in the combined sample. Lower CI&CIIOXPHOS significantly predicted GWI severity in the combined sample and in VGWI separately, with or without adjustment for hsCRP. Higher-hsCRP (peripheral inflammation) related strongly to lower-MRCF (particularly fatty acid oxidation (FAO) indices) in VGWI, but not in controls. Despite this, whereas greater MRCF-impairment predicted greater GWI symptoms and severity, greater inflammation did not. Surprisingly, adjusted for MRCF, higher hsCRP significantly predicted lesser symptom severity in VGWI selectively. Findings comport with a hypothesis in which the increased inflammation observed in GWI is driven by FAO-defect-induced mitochondrial apoptosis. In conclusion, impaired mitochondrial function-but not peripheral inflammation-predicts greater GWI symptoms and severity.

Combinations of classical and non-classical voltage dependent potassium channel openers suppress nociceptor discharge and reverse chronic pain signs in a rat model of Gulf War illness

In a companion paper we examined whether combinations of K_v7 channel openers (Retigabine and Diclofenac; RET, DIC) could be effective modifiers of deep tissue nociceptor activity; and whether such combinations could then be optimized for use as safe analgesics for pain-like signs that developed in a rat model of GWI (Gulf War Illness) pain. In the present report, we examined the combinations of Retigabine/Meclofenamate (RET/MEC) and Meclofenamate/Diclofenac (MEC/DIC). Voltage clamp experiments were performed on deep tissue nociceptors isolated from rat DRG (dorsal root ganglion). In voltage clamp studies, a stepped voltage protocol was applied (-55 to -40 mV; V_h=-60 mV; 1500 msec) and K_v7 evoked currents were subsequently isolated by Linopirdine subtraction. MEC greatly enhanced voltage dependent conductance and produced exceptional maximum sustained currents of 6.01 ± 0.26 pA/pF (EC₅₀: 62.2 ± 8.99 μM). Combinations of RET/MEC, and MEC/DIC substantially amplified resting currents at low concentrations. MEC/DIC also greatly improved voltage dependent conductance. In current clamp experiments, a cholinergic challenge test (Oxotremorine-M, 10 μM; OXO), associated with our GWI rat model, produced powerful action potential (AP) bursts (85 APs). Optimized combinations of RET/MEC (5 and 0.5 μM) and MEC/DIC (0.5 and 2.5 μM) significantly reduced AP discharges to 3 and 7 Aps, respectively. Treatment of pain-like ambulatory behavior in our rat model with a RET/MEC combination (5 and 0.5 mg/kg) successfully rescued ambulation deficits, but could not be fully separated from the effect of RET alone. Further development of this approach is recommended.

The ambivalence about accepting the prevalence somatic symptoms in PTSD: Is PTSD a somatic disorder?

This study examined the prevalence of somatic symptoms in post-traumatic stress disorder (PTSD) in a population-based military sample (N = 14,445). Descriptive statistics explored somatic symptom endorsement in the entire sample. A latent class analyses was conducted on participants with a posttraumatic stress checklist (PCL) score ≥29 (n = 2433), with class differentiated by somatic symptom endorsement.Multinomial logistic regression explored correlates of latent class. Somatic disorder was more prevalent in probable-PTSD (59.6%) and subsyndromal-PTSD (26.5%) than no-PTSD (5.0%) groups, supporting an intersection of pathophysiological processes between somatic and PTSD symptoms. A 3-class solution of Syndromal (26.7%),Psychological (17.7%), and Somatic (55.5%) classes provided the optimal representation of latent somatic symptom typologies in probable PTSD and subsyndromal PTSD. Differences between classes on key characteristics supported potentially meaningful class distinctions. Class was not predicted by number of deployments nor whether a member had ever deployed. However, class was predicted by life-time trauma, indicating that the PTSD somatic symptom relationship is not confined to combat related PTSD or the effect of toxic exposures on deployment, but that pre-existing pathophysiology related to life-time trauma may drive the relationship.The high degree of coincidence between PTSD and somatic symptoms and the high prevalence of somatic distress in the Syndromal and Somatic classes support somatic symptoms are a ubiquitous aspect of the clinical presentation and should be considered a central characteristic of PTSD and therefore included in the diagnostic criteria, as suggested by the original formulations of PTSD.

Opioid use as a predictor of pain outcomes in Iraq and Afghanistan Veterans with chronic pain: Analysis of a randomized controlled trial

OBJECTIVE

Our objectives were to: 1) assess the relationship between self-reported opioid use and baseline demographics, clinical characteristics and pain outcomes; and 2) examine whether baseline opioid use moderated the intervention effect on outcomes at 9 months.

DESIGN

We conducted a secondary analysis of data from the Evaluation of Stepped Care for Chronic Pain (ESCAPE) trial, which found stepped-care to be effective for chronic pain in military veterans.

SETTING

A post-deployment clinic and 5 general medicine clinics at a Veteran Affairs Medical Center.

SUBJECTS

241 veterans with chronic musculoskeletal pain; 220 with complete data at 9 months.

METHODS

Examination of baseline relationships and multivariable linear regression to examine baseline opioid use as a moderator of pain-related outcomes including Roland Morris Disability Questionnaire (RMDQ), Brief Pain Inventory (BPI) Interference scale, and Graded Chronic Pain Scale (GCPS) at 9 months.

RESULTS

Veterans reporting baseline opioid use (n = 80) had significantly worse RMDQ (16.0 ± 4.9 vs. 13.4 ± 4.2, P < 0.0001), GCPS (68.7 ± 12.0 vs. 65.0 ± 14.4, p = 0.049), BPI Interference (6.2 ± 2.2 vs. 5.0 ± 2.1, P < 0.0001), and depression (PHQ-9 12.5 ± 6.2 vs. 10.6 ± 5.7, p = 0.016) compared to veterans not reporting baseline opioid use. Using multivariable modeling we found that baseline opioid use moderated the intervention effect on pain-related disability (RMDQ) at 9 months (interaction Beta = -3.88, p = 0.0064), but not pain intensity or interference.

CONCLUSIONS

In a stepped-care trial for pain, patients reporting baseline opioid use had greater improvement in pain disability at 9 months compared to patients not reporting opioid use.

Multifocal Pain as a Predictor of Pain Outcomes in Military Veterans with Chronic Musculoskeletal Pain: A Secondary Data Analysis of a Randomized Controlled Trial

OBJECTIVE

We aimed to examine 1) the relationship between multifocal pain and clinical characteristics, including demographics, pain outcomes, somatic symptoms, health-related quality of life, depression, and anxiety, and 2) whether multifocal pain was independently associated with treatment response.

METHODS

We conducted a secondary data analysis on veterans with chronic pain enrolled in the Evaluation of Stepped Care for Chronic Pain (ESCAPE) trial with complete data at 9 months (n = 222). We examined baseline relationships and used multivariable linear regression to examine whether multifocal pain was independently associated with outcomes that included Brief Pain Inventory (BPI) Interference scale and Graded Chronic Pain Scale (GCPS) scores between baseline and 9 months.

RESULTS

The sample had a mean BPI Interference score of 5.3 ± 2.2 and a mean GCPS score of 65.6 ± 13.7, 55% had significant depression (Patient Health Questionnaire 9-item depression scale [PHQ-9] score of ≥10), and 42% had significant anxiety (Generalized Anxiety Disorder Scale [GAD-7] score of ≥10). Veterans reporting three or more pain sites (the "more diffuse pain" group) had significantly less improvement on GCPS (b = 4.6, standard error [SE] = 2.3, P = 0.045), BPI Interference (b = 1.0, SE = 0.2, P = 0.0011), and health-related quality of life (Short-Form 36-item scale, Physical Component Summary) (b = 4.1, SE = 1.0, P < 0.0001) than did veterans reporting fewer than three pain sites (the "less diffuse pain" group). More diffuse pain was not associated with changes in PHQ-9 or GAD-7 scores.

CONCLUSIONS

Multifocal pain predicted worse pain outcomes between baseline and 9 months in veterans enrolled in a trial for treating chronic musculoskeletal pain.

A review of pre-clinical models for Gulf War Illness

Gulf War Illness (GWI) is a chronic multisymptomatic disorder that afflicts over 1/3rd of the 1991 GW veterans. It spans multiple bodily systems and presents itself as a syndrome exhibiting diverse symptoms including fatigue, depression, mood, and memory and concentration deficits, musculoskeletal pain and gastrointestinal distress in GW veterans. The etiology of GWI is complex and many factors, including chemical, physiological, and environmental stressors present in the GW arena, have been implicated for its development. It has been over 30 years since the end of the GW but, GWI has been persistent in suffering veterans who are also dealing with paucity of effective treatments. The multifactorial aspect of GWI along with genetic heterogeneity and lack of available data surrounding war-time exposures have proved to be challenging in developing pre-clinical models of GWI. Despite this, over a dozen GWI animal models exist in the literature. In this article, following a brief discussion of GW history, GWI definitions, and probable causes for its pathogenesis, we will expand upon various experimental models used in GWI laboratory research. These animal models will be discussed in the context of their attempts at mimicking GW-related exposures with regards to the variations in chemical combinations, doses, and frequency of exposures. We will discuss their advantages and limitations in modeling GWI followed by a discussion of behavioral and molecular findings in these models. The mechanistic data obtained from these preclinical studies have offered multiple molecular pathways including chronic inflammation, mitochondrial dysfunction, oxidative stress, lipid disturbances, calcium homeostatic alterations, changes in gut microbiota, and epigenetic modifications, amongst others for explaining GWI development and its persistence. Finally, these findings have also informed us on novel druggable targets in GWI. While, it has been difficult to conceive a single pre-clinical model that could express all the GWI signs and exhibit biological complexity reflective of the clinical presentation in GWI, animal models have been critical for identifying molecular underpinnings of GWI and evaluating treatment strategies for GWI.

The Associations Between Physical and Psychological Symptoms and Traumatic Military Deployment Exposures

Current paradigms regarding the effects of traumatic exposures on military personnel do not consider physical symptoms unrelated to injury or illness as independent outcomes of trauma exposure, characteristically dealing with these symptoms as comorbidities of psychological disorders. Our objective was to ascertain the proportions of deployed military personnel who experienced predominantly physical symptoms, predominantly psychological symptoms, and comorbidity of the two and to examine the association between traumatic deployment exposures (TDEs) and these symptomatic profiles. Data were taken from a cross-sectional study of Australian Defence Force personnel who were deployed to the Middle East during 2001-2009 (N = 14,032). Four groups were created based on distributional splits of physical and psychological symptom scales: low-symptom, psychological, physical, and comorbid. Multinomial logistic regression models assessed the probability of symptom group membership, compared with low-symptom, as predicted by self-reported TDEs. Group proportions were: low-symptom, 78.3%; physical, 5.0%; psychological, 9.3%; and comorbid, 7.5%. TDEs were significant predictors of all symptom profiles. For subjective, objective, and human death and degradation exposures, respectively, the largest relative risk ratios (RRRs) were for the comorbid profile, RRRs = 1.47, 1.19, 1.48; followed by the physical profile, RRRs = 1.27, 1.15, 1.40; and the psychological profile, RRRs = 1.22, 1.07, 1.22. Almost half of participants with physical symptoms did not have comorbid psychological symptoms, suggesting that physical symptoms can occur as a discrete outcome trauma exposure. The similar dose-response association between TDEs and the physical and psychological profiles suggests trauma is similarly associated with both outcomes.

Identifying clusters of health symptoms in deployed military personnel and their relationship with probable PTSD

OBJECTIVE

Among military personnel posttraumatic stress disorder is strongly associated with non-specific health symptoms and can have poor treatment outcomes. This study aimed to use machine learning to identify and describe clusters of self-report health symptoms and examine their association with probable PTSD, other psychopathology, traumatic deployment exposures, and demographic factors.

METHOD

Data were from a large sample of military personnel who deployed to the Middle East (n = 12,566) between 2001 and 2009. Participants completed self-report measures including health symptoms and deployment trauma checklists, and several mental health symptom scales. The data driven machine learning technique of self-organised maps identified health symptom clusters and logistic regression examined their correlates.

RESULTS

Two clusters differentiated by number and severity of health symptoms were identified: a small 'high health symptom cluster' (HHSC; n = 366) and a large 'low health symptom cluster' (LHSC; n = 12,200). The HHSC had significantly higher proportions of (Gates et al., 2012 [1]) scaled scores indicative of PTSD (69% compared with 2% of LHSC members), Unwin et al. (1999a) [2] scores on other psychological scales that were indicative of psychopathology, and (Graham et al., n.d. [3]) deployment trauma. HHSC members with probable PTSD had a stronger relationship with subjective (OR 1.25; 95% CI 1.12, 1.40) and environmental (OR 1.08; 95% CI 1.03, 1.13) traumatic deployment exposures than LHSC members with probable PTSD.

CONCLUSION

These findings highlights that health symptoms are not rare in military veterans, and that PTSD is strongly associated with health symptoms. Results suggest that there may be subtypes of PTSD, differentiated by health symptoms.

Progression of intervention-focused research for Gulf War illness

The Persian Gulf War of 1990 to 1991 involved the deployment of nearly 700,000 American troops to the Middle East. Deployment-related exposures to toxic substances such as pesticides, nerve agents, pyridostigmine bromide (PB), smoke from burning oil wells, and petrochemicals may have contributed to medical illness in as many as 250,000 of those American troops. The cluster of chronic symptoms, now referred to as Gulf War Illness (GWI), has been studied by many researchers over the past two decades. Although over $500 million has been spent on GWI research, to date, no cures or condition-specific treatments have been discovered, and the exact pathophysiology remains elusive.Using the 2007 National Institute of Health (NIH) Roadmap for Medical Research model as a reference framework, we reviewed studies of interventions involving GWI patients to assess the progress of treatment-related GWI research. All GWI clinical trial studies reviewed involved investigations of existing interventions that have shown efficacy in other diseases with analogous symptoms. After reviewing the published and ongoing registered clinical trials for cognitive-behavioral therapy, exercise therapy, acupuncture, coenzyme Q10, mifepristone, and carnosine in GWI patients, we identified only four treatments (cognitive-behavioral therapy, exercise therapy, CoQ10, and mifepristone) that have progressed beyond a phase II trial.We conclude that progress in the scientific study of therapies for GWI has not followed the NIH Roadmap for Medical Research model. Establishment of a standard case definition, prioritized GWI research funding for the characterization of the pathophysiology of the condition, and rapid replication and adaptation of early phase, single site clinical trials could substantially advance research progress and treatment discovery for this condition.

Metabolic features of Gulf War illness

BACKGROUND

More than 230,000 veterans-about 1/3 of US personnel deployed in the 1990-1991 Persian Gulf War-developed chronic, multi-symptom health problems now called "Gulf War illness" (GWI), for which mechanisms and objective diagnostic signatures continue to be sought.

METHODS

Targeted, broad-spectrum serum metabolomics was used to gain insights into the biology of GWI. 40 male participants, included 20 veterans who met both Kansas and CDC diagnostic criteria for GWI and 20 nonveteran controls without similar symptoms that were 1:1 matched to GWI cases by age, sex, and ethnicity. Serum samples were collected and archived at -80° C prior to testing. 358 metabolites from 46 biochemical pathways were measured by hydrophilic interaction liquid chromatography and tandem mass spectrometry.

RESULTS

Veterans with GWI, compared to healthy controls, had abnormalities in 8 of 46 biochemical pathways interrogated. Lipid abnormalities accounted for 78% of the metabolic impact. Fifteen ceramides and sphingomyelins, and four phosphatidylcholine lipids were increased. Five of the 8 pathways were shared with the previously reported metabolic phenotype of males with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). However, 4 of the 5 shared pathways were regulated in opposite directions; key pathways that were up-regulated in GWI were down-regulated in ME/CFS. The single pathway regulated in the same direction was purines, which were decreased.

CONCLUSIONS

Our data show that despite heterogeneous exposure histories, a metabolic phenotype of GWI was clearly distinguished from controls. Metabolomic differences between GWI and ME/CFS show that common clinical symptoms like fatigue can have different chemical mechanisms and different diagnostic implications. Larger studies will be needed to validate these findings.

Behavioral, cellular and molecular maladaptations covary with exposure to pyridostigmine bromide in a rat model of gulf war illness pain

Many veterans of Operation Desert Storm (ODS) struggle with the chronic pain of Gulf War Illness (GWI). Exposure to insecticides and pyridostigmine bromide (PB) have been implicated in the etiology of this multisymptom disease. We examined the influence of 3 (DEET (N,N-diethyl-meta-toluamide), permethrin, chlorpyrifos) or 4 GW agents (DEET, permethrin, chlorpyrifos, pyridostigmine bromide (PB)) on the post-exposure ambulatory and resting behaviors of rats. In three independent studies, rats that were exposed to all 4 agents consistently developed both immediate and delayed ambulatory deficits that persisted at least 16 weeks after exposures had ceased. Rats exposed to a 3 agent protocol (PB excluded) did not develop any ambulatory deficits. Cellular and molecular studies on nociceptors harvested from 16WP (weeks post-exposure) rats indicated that vascular nociceptor Na_v1.9 mediated currents were chronically potentiated following the 4 agent protocol but not following the 3 agent protocol. Muscarinic linkages to muscle nociceptor TRPA1 were also potentiated in the 4 agent but not the 3 agent, PB excluded, protocol. Although K_v7 activity changes diverged from the behavioral data, a K_v7 opener, retigabine, transiently reversed ambulation deficits. We concluded that PB played a critical role in the development of pain-like signs in a GWI rat model and that shifts in Na_v1.9 and TRPA1 activity were critical to the expression of these pain behaviors.

Thwarted belongingness as an explanatory link between insomnia symptoms and suicidal ideation: Findings from three samples of military service members and veterans

BACKGROUND

Although insomnia has been identified as a robust predictor of suicidal ideation and behaviors, little is known about the mechanisms by which sleep disturbances confer risk for suicide. We investigated thwarted belongingness as an explanatory link between insomnia symptoms and suicidal ideation across three military service member and veteran samples.

METHODS

Data were collected among United States military service members and veterans (N1=937, N2=3,386, N3=417) who completed self-report measures of insomnia symptoms, thwarted belongingness, suicidal ideation, and related psychiatric symptoms (e.g., anxiety, hopelessness). Bias-corrected bootstrap mediation analyses were utilized to examine the indirect effects of insomnia symptoms on suicidal ideation through thwarted belongingness, controlling for related psychiatric symptoms.

RESULTS

Consistent with study hypotheses, thwarted belongingness significantly accounted for the relationship between insomnia and suicidal ideation across all three samples; however, insomnia symptoms did not significantly account for the relationship between thwarted belongingness and suicidal ideation, highlighting the specificity of our findings.

LIMITATIONS

This study utilized cross-sectional self-report data.

CONCLUSIONS

Insomnia may confer suicide risk for military service members and veterans, in part, through the pathway of thwarted belongingness. Additional prospective studies are warranted to further delineate this model of risk. Our results offer a potential therapeutic target for the prevention of suicide, via the promotion of belongingness, among service members and veterans experiencing insomnia symptoms.

Effects of Blast Exposure on Subjective and Objective Sleep Measures in Combat Veterans with and without PTSD

STUDY OBJECTIVES

This study examined the extent to which self-reported exposure to blast during deployment to Iraq and Afghanistan affects subjective and objective sleep measures in service members and veterans with and without posttraumatic stress disorder (PTSD).

METHODS

Seventy-one medication-free service members and veterans (mean age = 29.47 ± 5.76 years old; 85% men) completed self-report sleep measures and overnight polysomnographic studies. Four multivariate analyses of variance (MANOVAs) were conducted to examine the impact of blast exposure and PTSD on subjective sleep measures, measures of sleep continuity, non-rapid eye movement (NREM) sleep parameters, and rapid eye movement (REM) sleep parameters.

RESULTS

There was no significant Blast × PTSD interaction on subjective sleep measures. Rather, PTSD had a main effect on insomnia severity, sleep quality, and disruptive nocturnal behaviors. There was no significant Blast × PTSD interaction, nor were there main effects of PTSD or Blast on measures of sleep continuity and NREM sleep. A significant PTSD × Blast interaction effect was found for REM fragmentation.

CONCLUSIONS

The results suggest that, although persistent concussive symptoms following blast exposure are associated with sleep disturbances, self-reported blast exposure without concurrent symptoms does not appear to contribute to poor sleep quality, insomnia, and disruptive nocturnal disturbances beyond the effects of PTSD. Reduced REM sleep fragmentation may be a sensitive index of the synergetic effects of both psychological and physical insults.

DEET potentiates the development and persistence of anticholinesterase dependent chronic pain signs in a rat model of Gulf War Illness pain

Exposure to DEET (N,N-diethyl-meta-toluamide) may have influenced the pattern of symptoms observed in soldiers with GWI (Gulf War Illness; Haley and Kurt, 1997). We examined how the addition of DEET (400mg/kg; 50% topical) to an exposure protocol of permethrin (2.6mg/kg; topical), chlorpyrifos (CP; 120mg/kg), and pyridostigmine bromide (PB;13mg/kg) altered the emergence and pattern of pain signs in an animal model of GWI pain (Nutter et al., 2015). Rats underwent behavioral testing before, during and after a 4week exposure: 1) hindlimb pressure withdrawal threshold; 2) ambulation (movement distance and rate); and 3) resting duration. Additional studies were conducted to assess the influence of acute DEET (10-100μM) on muscle and vascular nociceptor K_v7, K_DR, Na_v1.8 and Na_v1.9. We report that a 50% concentration of DEET enhanced the development and persistence of pain-signs. Rats exposed to all 4 compounds exhibited ambulation deficits that appeared 5-12weeks post-exposure and persisted through weeks 21-24. Rats exposed to only three agents (CP or PB excluded), did not fully develop ambulation deficits. When PB was excluded, rats also developed rest duration pain signs, in addition to ambulation deficits. There was no evidence that physiological doses of DEET acutely modified nociceptor K_v7, K_DR, Na_v1.8 or Na_v1.9 activities. Nevertheless, DEET augmented protocols decreased the conductance of K_v7 expressed in vascular nociceptors harvested from chronically exposed rats. We concluded that DEET enhanced the development and persistence of pain behaviors, but the anticholinesterases CP and PB played a determinant role.

Exposure to Gulf War Illness chemicals induces functional muscarinic receptor maladaptations in muscle nociceptors

Chronic pain is a component of the multisymptom disease known as Gulf War Illness (GWI). There is evidence that pain symptoms could have been a consequence of prolonged and/or excessive exposure to anticholinesterases and other GW chemicals. We previously reported that rats exposed, for 8 weeks, to a mixture of anticholinesterases (pyridostigmine bromide, chlorpyrifos) and a Nav (voltage activated Na(+) channel) deactivation-inhibiting pyrethroid, permethrin, exhibited a behavior pattern that was consistent with a delayed myalgia. This myalgia-like behavior was accompanied by persistent changes to Kv (voltage activated K(+)) channel physiology in muscle nociceptors (Kv7, KDR). In the present study, we examined how exposure to the above agents altered the reactivity of Kv channels to a muscarinic receptor (mAChR) agonist (oxotremorine-M). Comparisons between muscle nociceptors harvested from vehicle and GW chemical-exposed rats revealed that mAChR suppression of Kv7 activity was enhanced in exposed rats. Yet in these same muscle nociceptors, a Stromatoxin-insensitive component of the KDR (voltage activated delayed rectifier K(+) channel) exhibited decreased sensitivity to activation of mAChR. We have previously shown that a unique mAChR-induced depolarization and burst discharge (MDBD) was exaggerated in muscle nociceptors of rats exposed to GW chemicals. We now provide evidence that both muscle and vascular nociceptors of naïve rats exhibit MDBD. Examination of the molecular basis of the MDBD in naïve animals revealed that while the mAChR depolarization was independent of Kv7, the action potential burst was modulated by Kv7 status. mAChR depolarizations were shown to be dependent, in part, on TRPA1. We argue that dysfunction of the MDBD could be a functional convergence point for maladapted ion channels and receptors consequent to exposure to GW chemicals.

Coenzyme Q10 benefits symptoms in Gulf War veterans: results of a randomized double-blind study

We sought to assess whether coenzyme Q10 (CoQ10) benefits the chronic multisymptom problems that affect one-quarter to one-third of 1990-1 Gulf War veterans, using a randomized, double-blind, placebo-controlled study. Participants were 46 veterans meeting Kansas and Centers for Disease Control criteria for Gulf War illness. Intervention was PharmaNord (Denmark) CoQ10 100 mg per day (Q100), 300 mg per day (Q300), or an identical-appearing placebo for 3.5 ± 0.5 months. General self-rated health (GSRH), the primary outcome, differed across randomization arms at baseline, and sex significantly predicted GSRH change, compelling adjustment for baseline GSRH and prompting sex-stratified analysis. GSRH showed no significant benefit in the combined-sex sample. Among males (85% of participants), Q100 significantly benefited GSRH versus placebo and versus Q300, providing emphasis on Q100. Physical function (summary performance score, SPS) improved on Q100 versus placebo. A rise in CoQ10 approached significance as a predictor of improvement in GSRH and significantly predicted SPS improvement. Among 20 symptoms each present in half or more of the enrolled veterans, direction-of-difference on Q100 versus placebo was favorable for all except sleep problems; sign test 19:1, p=0.00004) with several symptoms individually significant. Significance for these symptoms despite the small sample underscores large effect sizes, and an apparent relation of key outcomes to CoQ10 change increases prospects for causality. In conclusion, Q100 conferred benefit to physical function and symptoms in veterans with Gulf War illness. Examination in a larger sample is warranted, and findings from this study can inform the conduct of a larger trial.

Treatment for insomnia in combat-exposed OEF/OIF/OND military veterans: preliminary randomized controlled trial

Chronic insomnia is highly prevalent among military personnel returning from Iraq and Afghanistan. We evaluated the effects of a military version of a brief behavioral treatment of insomnia (BBTI-MV) compared to an information only control (IC) condition in combat-exposed Veterans of Operations Enduring/Iraqi Freedom or Operation New Dawn (OEF/OIF/OND) on insomnia, sleep quality, and daytime symptoms of anxiety and depression. Forty OEF/OIF/OND Veterans (Mean age = 38.4 years old, s.d. = 11.69; 85% men; 77.5% white) were randomized to one of two conditions. BBTI-MV consisted of two in-person sessions and two telephone contacts delivered over four weeks, and included personalized recommendations to reduce insomnia. The IC condition also consisted of 2 in-person sessions two telephone contacts delivered over four weeks, and Veterans were encouraged to read written information about sleep-promoting behaviors. The Insomnia Severity Index, Pittsburgh Sleep Quality Index, PTSD Checklist, and Beck Depression and Anxiety Inventories were completed at baseline, post-treatment, and at the six-month follow-up. Both interventions were associated with clinically significant improvements in insomnia, although the magnitude of improvements in sleep and rates of treatment response and remission were greater for BBTI-MV compared to IC from pre- to post-treatment. Both BBTI-MV and the provision of information were associated with clinically significant improvements in insomnia among Veterans. Despite the preliminary nature of the findings and limitations inherent to small controlled trials, the findings suggest that both approaches may provide viable options in a stepped-care approach to the treatment of insomnia in retuning combat-exposed Veterans. Larger, confirmatory effectiveness trials are required.

CLINICALTRIALSGOV IDENTIFIER

NCT00840255.

Mitochondrial dysfunction in Gulf War illness revealed by 31Phosphorus Magnetic Resonance Spectroscopy: a case-control study

BACKGROUND

Approximately 1/3 of 1990-1 Gulf War veterans developed chronic multisymptom health problems. Implicated exposures bear mechanisms that adversely affect mitochondria. Symptoms emphasize fatigue, cognition and muscle (brain and muscle are aerobically demanding); with protean additional domains affected, compatible with mitochondrial impairment. Recent evidence supports treatments targeting cell bioenergetics (coenzyme10) to benefit Gulf War illness symptoms. However, no evidence has directly documented mitochondrial or bioenergetic impairment in Gulf War illness.

OBJECTIVE

We sought to objectively assess for mitochondrial dysfunction, examining post-exercise phosphocreatine-recovery time constant (PCr-R) using (31)Phosphorus Magnetic Resonance Spectroscopy ((31)P-MRS), in Gulf War veterans with Gulf War illness compared to matched healthy controls. PCr-R has been described as a "robust and practical" index of mitochondrial status.

DESIGN AND PARTICIPANTS

Case-control study from 2012-2013. Fourteen community-dwelling Gulf War veterans and matched controls from the San Diego area comprised 7 men meeting CDC and Kansas criteria for Gulf War illness, and 7 non-deployed healthy controls matched 1:1 to cases on age, sex, and ethnicity.

OUTCOME MEASURE

Calf muscle phosphocreatine was evaluated by (31)P-MRS at rest, through 5 minutes of foot pedal depression exercise, and in recovery, to assess PCr-R. Paired t-tests compared cases to matched controls.

RESULTS

PCr-R was significantly prolonged in Gulf War illness cases vs their matched controls: control values, mean ± SD, 29.0 ± 8.7 seconds; case values 46.1 ± 18.0 seconds; difference 17.1 ± 14.9 seconds; p = 0.023. PCr-R was longer for cases relative to their matched controls for all but one pair; moreover while values clustered under 31 seconds for all but one control, they exceeded 35 seconds (with a spread up to 70 seconds) for all but one case.

DISCUSSION

These data provide the first direct evidence supporting mitochondrial dysfunction in Gulf War illness. Findings merit replication in a larger study and/or corroboration with additional mitochondrial assessment tools.

Multiple physical symptoms in a military population: a cross-sectional study

BACKGROUND

Medically unexplained symptoms have been reported among both civilians and military personnel exposed to combat. A large number of military personnel deployed to the Gulf War in 1991 reported non-specific symptoms. These symptoms did not constitute a clearly defined syndrome. Post-traumatic stress disorder (PTSD) and to a lesser degree exposure to combat are associated with physical symptoms.

METHODS

This is a cross-sectional study of representative samples of Sri Lanka Navy Special Forces and regular forces deployed in combat areas continuously during a 1-year period. Multiple physical symptoms were elicited using a checklist of 53 symptoms. Cases were defined as individuals with ten or more symptoms. Symptoms of common mental disorder were identified using the General Health Questionnaire 12 (GHQ-12). PTSD was diagnosed using the 17-item National Centre for PTSD checklist civilian version.

RESULTS

Prevalence of multiple physical symptoms was 10.4% (95% CI 8.11-12.75). Prevalence was significantly less in the Special Forces (5.79%) than in the regular forces (13.35%). The mean number of symptoms reported by those who met the criteria for PTSD was 12.19 (SD 10.58), GHQ caseness 7.87 (SD 7.57) and those without these conditions 2.84 (SD 3.63). After adjusting for socio-demographic and service variables, 'thought I might be killed' , 'coming under small arms fire' , and 'coming under mortar, missile and artillery fire' remained significant. Multiple physical symptoms were associated with functional impairment and poor perceived general health.

CONCLUSIONS

Prevalence of multiple physical symptoms was significantly lower in the Special Forces despite high exposure to potentially traumatic events. More multiple physical symptoms were reported by personnel with PTSD and common mental disorders. Multiple physical symptoms were associated with functional impairment.

Military service and lung disease

Military personnel can be exposed to toxicants and conditions that can contribute to lung diseases. This article describes what is known about these exposures and diseases, focusing on the Iraq and Afghanistan wars. Adverse lung health outcomes have been reported in US military personnel deployed to Iraq and/or Afghanistan. Most studies to date have been hindered by limited deployment-specific exposure assessment, lack of baseline lung health information, and variable medical evaluations and case definitions. Further research is warranted. Medical surveillance has been recommended for returning troops, but the challenges are substantial.

Diagnosis and management of chronic lung disease in deployed military personnel

Military personnel are a unique group of individuals referred to the pulmonary physician for evaluation. Despite accession standards that limit entrance into the military for individuals with various pre-existing lung diseases, the most common disorders found in the general population such as asthma and chronic obstructive pulmonary disease remain frequently diagnosed. Military personnel generally tend to be a more physically fit population who are required to exercise on a regular basis and as such may have earlier presentations of disease than their civilian counterparts. Exertional dyspnea is a common complaint; establishing a diagnosis may be challenging given the subtle nature of symptoms and lack of specificity with pulmonary function testing. The conflicts over the past 10 years in Iraq and Afghanistan have also given rise to new challenges for deployed military. Various respiratory hazards in the deployed environment include suspended geologic dusts, burn pits, vehicle exhaust emissions, industrial air pollution, and isolated exposure incidents and may give rise to both acute respiratory symptoms and chronic lung disease. In the evaluation of deployed military personnel, establishing the presence of actual pulmonary disease and the relationship of existing disease to deployment is an ongoing issue to both military and civilian physicians. This paper reviews the current evidence for chronic lung disease in the deployed military population and addresses any differences in diagnosis and management.

An assessment of survey measures used across key epidemiologic studies of United States Gulf War I Era veterans

Over the past two decades, 12 large epidemiologic studies and 2 registries have focused on U.S. veterans of the 1990-1991 Gulf War Era. We conducted a review of these studies' research tools to identify existing gaps and overlaps of efforts to date, and to advance development of the next generation of Gulf War Era survey tools. Overall, we found that many of the studies used similar instruments. Questions regarding exposures were more similar across studies than other domains, while neurocognitive and psychological tools were the most variable. Many studies focused on self-reported survey results, with a range of validation practices. However, physical exams, biomedical assessments, and specimen storage were not common. This review suggests that while research may be able to pool data from past surveys, future surveys need to consider how their design can yield data comparable with previous surveys. Additionally, data that incorporate recent technologies in specimen and genetic analyses would greatly enhance such survey data. When combined with existing data on deployment-related exposures and post-deployment health conditions, longitudinal follow-up of existing studies within this collaborative framework could represent an important step toward improving the health of veterans.

Prevalence of environmental and other military exposure concerns in Operation Enduring Freedom and Operation Iraqi Freedom veterans

OBJECTIVE

This study examined the prevalence of self-reported exposures in returning Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF) veterans and the relationship of exposure reports to current physical symptoms.

METHODS

Using self-reports obtained immediately after return from deployment in a cohort of 760 enlisted Army reserve component military personnel, we assessed prevalence rates of environmental and other exposures and the association of these exposures to severity of physical symptoms.

RESULTS

Reporting of environmental exposures was relatively low in veterans of OEF/OIF, but reporting more environmental and other exposures, in particular screening positive for a traumatic brain injury, was related to greater physical symptom severity immediately after deployment.

CONCLUSIONS

Non-treatment-seeking, enlisted Army reserve component personnel reported relatively few exposures immediately after return from deployment; however, more exposures was modestly associated with greater severity of physical symptoms when controlling for predeployment symptoms, gender, and other deployment-related exposures.

Placebo-controlled comparison of prazosin and cognitive-behavioral treatments for sleep disturbances in US Military Veterans

OBJECTIVE

Pharmacological and cognitive-behavioral treatments targeting insomnia and nightmares have been shown to be effective in the treatment of military veterans with sleep complaints comorbid with symptoms of stress-related disorders, including Post-Traumatic Stress Disorder (PTSD), but the two approaches have not been directly compared. This randomized controlled trial compared the effects of prazosin vs. a behavioral sleep intervention (BSI), targeting nightmares and insomnia against a placebo pill control condition on sleep and daytime symptoms.

METHODS

Fifty United States military veterans (mean age 40.9years, SD=13.2years) with chronic sleep disturbances were randomized to prazosin (n=18), BSI (n=17), or placebo (n=15). Each intervention lasted 8weeks. Participants completed self-report measures of insomnia severity, sleep quality, and sleep disturbances. All kept a sleep diary throughout the intervention period. Polysomnographic studies were conducted pre- and post-intervention.

RESULTS

Both active treatment groups showed greater reductions in insomnia severity and daytime PTSD symptom severity. Sleep improvements were found in 61.9% of those who completed the active treatments and 25% of those randomized to placebo.

CONCLUSION

BSI and prazosin were both associated with significant sleep improvements and reductions in daytime PTSD symptoms in this sample of military veterans. Sleep-focused treatments may enhance the benefits of first-line PTSD treatments.

The burden of illness in the first year home: do male and female VA users differ in health conditions and healthcare utilization

BACKGROUND

we sought to describe gender differences in medical and mental health conditions and health care utilization among veterans who used Veterans Health Administration (VA) services in the first year after combat in Iraq and Afghanistan.

METHODS

this is an observational study, using VA administrative and clinical data bases, of 163,812 Operation Enduring Freedom/Operation Iraqi Freedom veterans who had enrolled in VA and who had at least one visit within 1 year of last deployment.

RESULTS

female veterans were slightly younger (mean age, 30 years vs. 32 for men; p <.0001), twice as likely to be African American (30% vs. 15%; p <.0001), and less likely to be married (32% vs. 49%; p < .0001). Women had more visits to primary care (2.6 vs. 2.0; p < .001) and mental health (4.0 vs. 3.6; p < .001) clinics and higher use of community care outside the VA (14% vs. 10%; p < .001). After adjustment for significant demographic differences, women were more likely to have musculoskeletal and skin disorders, mild depression, major depression, and adjustment disorders, whereas men were more likely to have ear disorders and posttraumatic stress disorder. Thirteen percent of women sought care for gynecologic examination, 10% for contraceptive counseling, and 7% for menstrual disorders.

CONCLUSION

female veterans had similar rates of physical conditions, but higher rates of some mental health disorders and additionally, used the VA for reproductive health needs. They also had slightly greater rates of health care service use. These findings highlight the complexity of female Veteran health care and support the development of enhanced comprehensive women's health services within the VA.

Pain among Veterans of Operations Enduring Freedom and Iraqi Freedom: do women and men differ?

OBJECTIVE

To evaluate sex differences in the prevalence of overall pain, moderate-severe pain, and persistent pain among Veterans of Operations Enduring Freedom and Iraqi Freedom seen at VA outpatient clinics, and to evaluate sex differences in pain assessment.

DESIGN

The observational cohort consisted of Veterans discharged from the U.S. military from October 1, 2001 to November 30, 2007 that enrolled for Veterans Administration (VA) services or received VA care before January 1, 2008. We limited the sample to the 153,212 Veterans (18,481 female, 134,731 male) who had 1 year of observation after their last deployment.

RESULTS

Pain was assessed in 59.7% (n = 91,414) of Veterans in this sample. Among those assessed, 43.3% (n = 39,591) reported any pain, 63.2% (n = 25,028) of whom reported moderate-severe pain. Over 20% (n = 3,427) of Veterans with repeated pain measures reported persistent pain. We found no significant difference in the probability of pain assessment by sex (RR = 0.98, 95% CI 0.96, 1.00). Female Veterans were less likely to report any pain (RR 0.89, 95% CI 0.86, 0.92). Among those with any pain, female Veterans were more likely to report moderate-severe pain (RR 1.05, 95% CI 1.01, 1.09) and less likely to report persistent pain (RR 0.90, 95% CI 0.81, 0.99).

CONCLUSIONS

As the VA plans care for the increasing numbers of female Veterans returning from Iraq and Afghanistan, a better understanding of the prevalence of pain, as well as sex-specific variations in the experience and treatment of pain, is important for policy makers and providers who seek to improve identification and management of diverse pain disorders.

Acetylcholinesterase inhibitors and Gulf War illnesses

Increasing evidence suggests excess illness in Persian Gulf War veterans (GWV) can be explained in part by exposure of GWV to organophosphate and carbamate acetylcholinesterase inhibitors (AChEis), including pyridostigmine bromide (PB), pesticides, and nerve agents. Evidence germane to the relation of AChEis to illness in GWV was assessed. Many epidemiological studies reported a link between AChEi exposure and chronic symptoms in GWV. The link is buttressed by a dose-response relation of PB pill number to chronic symptoms in GWV and by a relation between avidity of AChEi clearance and illness, based on genotypes, concentrations, and activity levels of enzymes that detoxify AChEis. Triangulating evidence derives from studies linking occupational exposure to AChEis to chronic health symptoms that mirror those of ill GWV. Illness is again linked to lower activity of AChEi detoxifying enzymes and genotypes conferring less-avid AChEi detoxification. AChEi exposure satisfies Hill's presumptive criteria for causality, suggesting this exposure may be causally linked to excess health problems in GWV.

Chronic Widespread Pain in Veterans of the First Gulf War: Impact of Deployment Status and Associated Health Effects

Our study sought to 1) determine if deployment status is associated with chronic widespread pain (CWP), and 2) evaluate whether veterans with CWP have greater psychiatric comorbidity, higher health care utilization, and poorer health status than veterans without CWP. Five years after the conclusion of the first Gulf War (August 1990 to June 1991), we conducted a cross-sectional study of veterans who listed Iowa as the home of record using a stratified sampling design to determine their health status. We compared the prevalence of CWP between deployed and nondeployed veterans. Logistic and multiple linear regression models were constructed to test whether CWP was associated with comorbidities and health-related outcomes of interest. Five hundred ninety of 3695 veterans interviewed (16%) had CWP. Gulf deployment was associated with higher prevalence of CWP than deployment elsewhere (OR = 2.03, 95%CI = 1.60-2.58), after adjustment. Both deployed and nondeployed veterans with CWP reported more health care utilization and comorbidities and lower health-related quality of life scores than veterans without CWP. Deployed veterans were more likely to have CWP than nondeployed veterans, and CWP was associated with poor health outcomes. Military and medical personnel should be aware that efforts to prevent, identify, and treat CWP in veterans returning from the current war may be needed.

PERSPECTIVE

This article indicates that deployed veterans may have an increased risk for development of CWP, which is associated with greater healthcare utilization and comorbidity and lower quality of life. The risk of poor health outcomes suggests that veterans returning from the present conflict should be screened for CWP on their return.

Latency and Exposure-Health Associations in Gulf War Veterans with Early Fatigue Onsets: A Case-control Study

PURPOSE

To see if self-reported exposures were associated with health in early-onset Gulf War illnesses (GWIs) cases and healthy Gulf War veteran controls.

METHODS

Forty-nine cases and 44 controls completed questionnaires about wartime exposures and symptoms experienced. Odds ratios were calculated using 2 x 2 tables and logistic regression. The incubation curve of fatigue onsets in cases was drawn to highlight exposure/health associations using Sartwell's method and tested with the Shapiro-Wilk test. The incubation period was defined as the time from arrival in the Persian Gulf to fatigue onset.

RESULTS

The incubation curve was right skewed and lognormally distributed (p = 0.48; p > 0.05 indicates lognormality), suggesting an association between a wartime exposure and fatigue. Exposure to oil fire smoke, pesticides, contaminated food or water, dead animals, scud missile attacks, dead bodies, prisoners of war, artillery or small arms fire, and chemical suits was significantly associated with GWIs. Pyridostigmine bromide (PB) was the only continuous exposure significantly associated with GWIs. The odds of having GWIs increased by 1.3% for every PB pill taken (95% confidence interval 1.001-1.02). There were significant trends toward worse health with greater intake of PB.

CONCLUSIONS

These analyses suggest that wartime exposures, including exposure to PB, are associated with fatigue.

Somatoform-spectrum diagnoses among medically evacuated "Operation Enduring Freedom" and "Operation Iraqi Freedom" personnel

Ten percent of military medical evacuees from military operations in Iraq and Afghanistan are psychiatric referrals. Three percent of these psychiatric patients had somatoform-spectrum disorders (SSDs). Potential reasons for this low rate include lower stigma for other types of psychiatric presentations and the possibilities that SSD patients have not yet emerged in clinical settings or are managed in deployment environments. SSD patients, compared with other veterans, are more likely to be enlisted-rank, younger, and an ethnic minority. They are more likely to have non-combat deployment stressors and past psychiatric histories than combat-specific stressors and family problems at home.

A comparison of the postdeployment hospitalization experience of U.S. military personnel following service in the 1991 Gulf War, Southwest Asia after the Gulf War, and Bosnia

Much attention has been given to the impact of deployment on the health of veterans from the 1991 Gulf War. Whereas increases in self-reported symptoms have been common, no specific exposures have been implicated. Some have suggested that stress from deployment is the chief cause for multisymptom conditions among Gulf War veterans, but comparisons with the health of other recent deployers have not been made. We sought to examine the impact of several large military deployments on hospitalization experience. Hospitalization records were examined for all active duty personnel deployed exclusively to the Gulf War, Southwest Asia after the Gulf War, or Bosnia. Cox's hazard modeling was used to assess time until first post-deployment hospitalization, separation from active duty, or December 31, 2000, whichever occurred first, while controlling for influential covariates and temporal changes. Personnel deployed to Southwest Asia after the 1991 Gulf War were at a slight increased risk for any-cause hospitalization and for 3 of the 14 major diagnostic categories when compared with veterans of the 1991 Gulf War. Personnel deployed to Bosnia were at a decreased risk for any-cause hospitalization and 12 of the 14 major diagnostic categories when compared with Gulf War veterans. These findings do not fully explain the complexity of postdeployment health experiences. Although the risk for hospitalization may be associated with regional deployment, it is unlikely that Gulf War veterans are at greater risk of hospitalization due to a specific exposure-related disease.

Pyridostigmine, diethyltoluamide, permethrin, and stress: a double-blind, randomized, placebo-controlled trial to assess safety

OBJECTIVE

To determine whether short-term human exposure to pyridostigmine bromide, diethyltoluamide, and permethrin, at rest or under stress, adversely affects short-term physical or neurocognitive performance.

PARTICIPANTS AND METHODS

A multicenter, prospective, double-blind, placebo-controlled crossover trial exposing 64 volunteers to permethrin-impregnated uniforms, diethyltoluamide-containing skin cream, oral pyridostigmine, and corresponding placebos was performed. Each participant had 4 separate sessions, ensuring exposure to all treatments and placebos under both stress and rest conditions in random order. Outcomes Included physical performance (handgrip strength and duration, stair climbing, and pull-ups [males] or push-ups [females]), neurocognitive performance (computerized tests), and self-reported adverse effects.

RESULTS

Permethrin was undetectable in the serum of all participants; pyridostigmine levels were higher Immediately after stress (41.6 ng/mL; 95% confidence Interval, 35.1-48.1 ng/mL) than rest (23.0 ng/mL; 95% confidence Interval, 19.2-26.9 ng/mL), whereas diethyltoluamide levels did not significantly differ by stress condition. Heart rate and systolic blood pressure increased significantly with stress compared with rest but did not vary with treatment vs placebo. Physical and neurocognitive outcome measures and self-reported adverse effects did not significantly differ by exposure group.

CONCLUSION

Combined, correct use of pyridostigmine, diethyltoluamide, and permethrin is well tolerated and without evidence of short-term physical or neurocognitive impairment.

Millennium Cohort: enrollment begins a 21-year contribution to understanding the impact of military service

OBJECTIVE

In response to health concerns of military members about deployment and other service-related exposures, the Department of Defense (DoD) initiated the largest prospective study ever undertaken in the U.S. military.

STUDY DESIGN AND SETTING

The Millennium Cohort uses a phased enrollment strategy to eventually include more than 100,000 U.S. service members who will be followed up through the year 2022, even after leaving military service. Subjects will be linked to DoD and Veterans Affairs databases and surveyed every 3 years to obtain objective and self-reported data on exposures and health outcomes.

RESULTS

The first enrollment phase was completed in July 2003 and resulted in 77,047 consenting participants, well representative of both active-duty and Reserve/Guard forces. This report documents the baseline characteristics of these Cohort members, describes traditional, postal, and Web-based enrollment methods; and describes the unique challenges of enrolling, retaining, and following such a large Cohort.

CONCLUSION

The Millennium Cohort was successfully launched and is becoming especially relevant, given current deployment and exposure concerns. The Cohort is representative of the U.S. military and promises to provide new insight into the long-term effects of military occupations on health for years to come.

Managing future Gulf War Syndromes: international lessons and new models of care

After the 1991 Gulf War, veterans of the conflict from the United States, United Kingdom, Canada, Australia and other nations described chronic idiopathic symptoms that became popularly known as 'Gulf War Syndrome'. Nearly 15 years later, some 250 million dollars in United States medical research has failed to confirm a novel war-related syndrome and controversy over the existence and causes of idiopathic physical symptoms has persisted. Wartime exposures implicated as possible causes of subsequent symptoms include oil well fire smoke, infectious diseases, vaccines, chemical and biological warfare agents, depleted uranium munitions and post-traumatic stress disorder. Recent historical analyses have identified controversial idiopathic symptom syndromes associated with nearly every modern war, suggesting that war typically sets into motion interrelated physical, emotional and fiscal consequences for veterans and for society. We anticipate future controversial war syndromes and maintain that a population-based approach to care can mitigate their impact. This paper delineates essential features of the model, describes its public health and scientific underpinnings and details how several countries are trying to implement it. With troops returning from combat in Afghanistan, Iraq and elsewhere, the model is already getting put to the test.

The challenges of exposure assessment in health studies of Gulf War veterans

A variety of exposures have been investigated in Gulf War veterans' health studies. These have most commonly been by self-report in a postal questionnaire but modelling and bio-monitoring have also been employed. Exposure assessment is difficult to do well in studies of any workplace environment. It is made more difficult in Gulf War studies where there are a number and variety of possible exposures, no agreed metrics for individual exposures and few contemporary records associating the exposure with an individual. In some studies, the exposure assessment was carried out some years after the war and in the context of media interest. Several studies have examined different ways to test the accuracy of exposure reporting in Gulf War cohorts. There is some evidence from Gulf War studies that self-reported exposures were subject to recall bias but it is difficult to assess the extent. Occupational exposure-assessment methodology can provide insights into the exposure-assessment process and how to do it well. This is discussed in the context of the Gulf War studies. Alternative exposure-assessment methodologies are presented, although these may not be suitable for widespread use in veteran studies. Due to the poor quality of and accessibility of objective military exposure records, self-assessed exposure questionnaires are likely to remain the main instrument for assessing the exposure for a large number of veterans. If this is to be the case, then validation methods with more objective methods need to be included in future study designs.

Toxicological assessments of Gulf War veterans

Concerns about unexplained illnesses among veterans of the 1991 Gulf War appeared soon after that conflict ended. Many environmental causes have been suggested, including possible exposure to depleted uranium munitions, vaccines and other drugs used to protect troops, deliberate or accidental exposure to chemical warfare agents and pesticides and smoke from oil-well fires. To help resolve these issues, US and UK governments have sought independent expert scientific advice from prestigious, independent scientific and public health experts, including the US National Academies of Science and the UK Royal Society and Medical Research Council. Their authoritative and independent scientific and medical reviews shed light on a wide range of Gulf War environmental hazards. However, they have added little to our understanding of Gulf War veterans' illnesses, because identified health effects have been previously well characterized, primarily in the occupational health literature. This effort has not identified any new health effects or unique syndromes associated with the evaluated environmental hazards. Nor do their findings provide an explanation for significant amounts of illnesses among veterans of the 1991 Gulf War. Nevertheless, these independent and highly credible scientific reviews have proven to be an effective means for evaluating potential health effects from deployment-related environmental hazards.

Military deployment to the Gulf War as a risk factor for psychiatric illness among US troops

BACKGROUND

Several studies document an excess of psychiatric symptoms among veterans of the the 1991 Gulf War. However, little is known about the prevalence of psychiatric disorders in those who were deployed to that conflict.

AIMS

To compare the 12-month prevalence and associated risk factors for DSM Axis I psychiatric diagnoses between random samples of Gulf War-deployed veterans and veterans of the same era not deployed to the Persian Gulf (era veterans).

METHOD

Interview data from 967 Gulf War veterans and 784 era veterans were examined to determine current health status, medical conditions, symptoms and Axis I psychiatric disorders. Logistic regression models evaluated risk factors for psychiatric disorder.

RESULTS

Gulf War veterans had a significantly higher prevalence of psychiatric diagnoses, with twice the prevalence of anxiety disorders and depression. Lower rank, female gender and divorced or single marital status were significant independent predictors of psychiatric disorder.

CONCLUSIONS

Deployment to the Gulf War is associated with a range of mental health outcomes more than 10 years after deployment.

Illnesses and injuries reported by Latino poultry workers in western North Carolina

BACKGROUND

Poultry processing is the largest sector of the meat products industry. Many workers are immigrants; few data exist on their illness and injury rates and the impact of workplace safety environment.

METHODS

Survey interviews were conducted with a representative sample of 200 Latino poultry workers employed by three different companies in western North Carolina; topics included symptoms, work-related illnesses and injuries, and plant safety climate.

RESULTS

Most respondents were <35 years of age and had been in the US <10 years. Frequency of self-reported symptoms was high, particularly for musculoskeletal symptoms. Despite symptoms, workers reported not missing work or seeking medical care. Occupational injuries and illnesses and symptoms varied by company. Between-company differences in injury and illness rates were consistent with perceived safety and company provision of personal protective equipment.

CONCLUSIONS

Symptoms reported exceeded rates reported by other community, clinical, and occupational samples. Findings suggest policy changes and research are needed to reduce the high rates of occupational illnesses and injuries in this vulnerable population.