Association of Gulf War Illness-Related Symptoms with Military Exposures among 1990-1991 Gulf War Veterans Evaluated at the War-Related Illness and Injury Study Center (WRIISC)

Associations Among Environmental Exposures and Physical and Psychiatric Symptoms in a Care-Seeking Sample of U.S. Military Veterans

INTRODUCTION

Recent research and policy (e.g., the Sergeant First Class (SFC) Heath Robinson Honoring our Promise to Address Comprehensive Toxics (PACT) Act) have highlighted the potential health consequences of toxic environmental exposures. The purpose of the current study was to assess the self-reported prevalence of such exposures among a sample of U.S. military veterans seeking care at a Veterans Affairs facility and to examine associations between exposures and physical and psychiatric symptoms.

MATERIALS AND METHODS

Participants were 4,647 newly enrolling post-9/11 veterans at the VA San Diego Healthcare System who completed standard clinical screening processes between January 2015 and April 2019. Electronic health screening data, including demographic information, military history, environmental exposures, and physical and psychiatric symptoms, were assessed. t-Tests for continuous variables and chi-square tests for categorical variables were used to compare exposed to unexposed veterans on demographic and military characteristics as well as physical and psychiatric symptoms.

RESULTS

A total of 2,028 veterans (43.6%) reported exposure to environmental toxins during their military service. Analyses revealed a disproportionate burden of exposure on older, male, educated, combat veterans as well as Asian and Native American veterans. Exposure to any type of environmental toxin was associated with more physical symptoms, particularly pain, fatigue, and insomnia, as well as psychiatric symptoms, including moderate depressive symptomology, mild to moderate anxiety, and scores approaching the threshold for likely post-traumatic stress disorder and alcohol misuse.

CONCLUSIONS

The high prevalence and detrimental health correlates of environmental exposures underscore the importance of implementing screening for exposures and providing healthcare services that address the multisystemic nature of exposure-related illness.

The Military Health History: An Educational Initiative to Improve Veteran Healthcare

INTRODUCTION

As a result of the nature of military service, veterans are a unique patient population with many special health considerations. For various reasons, measures are often not taken by clinicians to address such special considerations. This results in a healthcare disparity for veterans first described by Dr. Jeffrey Brown in 2012. To address this disparity, we introduced "the military health history" to third-year medical students at a large medical school in the southeastern United States. Our objective was to assess the effectiveness of this educational intervention and determine its potential role in creating a future in which veteran healthcare is of the highest quality.

MATERIALS AND METHODS

This study was approved as a quality assurance/quality improvement project by both Louisiana State University Health Science Center and Southeast Louisiana Veteran Healthcare System IRB offices. A short lecture outlining the components of the military health history was presented to 186 third-year medical students. The students were given the opportunity to answer five survey questions before and after the lecture. These questions assessed the students' current confidence performing a military health history, perceived importance of doing so, and likelihood of future implementation. To determine useful retention of the lecture material, the post-lecture survey was readministered to the same population sample 6 months after the lecture. A series of repeated measures analyses of variance were conducted to examine changes in mean levels of confidence, importance, and likelihood of ascertaining military history during a patient encounter at pre- and post-presentation as well as at the 6 month follow-up.

RESULTS

Results revealed a significant effect of time on importance, Wilks' Lambda = 0.74, F (2, 87) = 15.41, P < 0.001; confidence, Wilks' Lambda = 0.61, F (2, 87) = 27.58, P < 0.001; and likelihood of ascertaining a military history during a future patient encounter, Wilks' Lambda = 0.46, F (2, 88) = 50.58, P < 0.001. Results are demonstrated in detail in Table I of the manuscript.

CONCLUSION

The lecture resulted in a statistically significant increase over 6 months in both the likelihood and confidence parameters. The team believes that this result indicates that the students demonstrated useful retention of the lecture material. Our hope is that these students continue to employ the military health history throughout their years of clinical work. In the future, we plan to survey veterans immediately following Veterans Health Administration clinic visits with members of our study population to assess the patient's perceived benefit of the military health history. The team will continue to investigate ways in which military health curricula can be implemented in undergraduate medical education.

Irritable Bowel Syndrome in Veterans with Gulf War Illness Evaluated at VA's War-Related Illness and Injury Study Center

INTRODUCTION

Excess rates of Gulf War illness (GWI) and irritable bowel syndrome (IBS), two chronic multisymptom illnesses, have long been documented among nearly 700,000 veterans who served in the 1990-1991 Persian Gulf War. We sought to report the prevalence, characteristics, and association of GWI and IBS decades after the war in a clinical cohort of deployed Gulf War veterans (GWVs) who were evaluated at the Department of Veterans Affairs' War Related Illness and Injury Study Center (WRIISC) for unexplained chronic symptoms.

MATERIALS AND METHODS

We analyzed data gathered from clinical intake questionnaires of deployed GWVs who were evaluated at WRIISC clinics between 2008 and 2020. We applied Centers for Disease Control (CDC) criteria to determine the prevalence of severe GWI. IBS was identified using Rome IV diagnostic criteria (current IBS) and veterans' self-reported "history of physician-diagnosed IBS." We examined associations between IBS and GWI using bivariate analyses and multivariable logistic regression.

RESULTS

Among the N = 578 GWVs evaluated by the WRIISC, severe GWI (71.8%), history of physician-diagnosed IBS (50.3%) and current IBS (42.2%) were all highly prevalent. Nearly half of GWVs with severe GWI met Rome criteria for IBS (45.8%), and over half reported a history of physician-diagnosed IBS (56.1%). In multivariable models, severe GWI was significantly associated both with current IBS (adjusted odds ratio (aOR): 1.68, 95% CI: 1.11, 2.54) and with veteran-reported history of physician-diagnosed IBS (aOR: 2.15, 95% CI: 1.43, 2.23). IBS with diarrhea (IBS-D) was the most common subtype among GWVs with current IBS (61.1%). However, IBS-mixed affected a significantly greater proportion of veterans with severe GWI, compared to veterans who did not have severe GWI (P = .03).

CONCLUSIONS

More than 20 years after the Persian Gulf War, our findings indicate a high degree of comorbidity between severe GWI and IBS among deployed GWVs seeking care for unexplained illnesses. Our results suggest GWVs with GWI should be screened for IBS for which evidence-based treatments are available and could potentially reduce symptom burden. Conversely, symptoms of IBS should trigger additional evaluation for non-gastrointestinal symptoms in deployed Gulf War veterans to identify possible GWI and ensure a comprehensive approach to care.

Association of Atherosclerotic Cardiovascular Disease, Hypertension, Diabetes, and Hyperlipidemia With Gulf War Illness Among Gulf War Veterans

BACKGROUND

Approximately 30% of the 700 000 Gulf War veterans report a chronic symptom-based illness of varying severity referred to as Gulf War illness (GWI). Toxic deployment-related exposures have been implicated in the cause of GWI, some of which contribute to metabolic dysregulation and lipid abnormalities. As this cohort ages, the relationship between GWI and atherosclerotic cardiovascular disease (ASCVD) is a growing concern. We evaluated associations between GWI and ASCVD, diabetes, hyperlipidemia, and hypertension in veterans of the Gulf War (1990-1991).

METHODS AND RESULTS

Analysis of survey data collected in 2014 to 2016 from a national sample of deployed Gulf War veterans (n=942) and Veterans Health Administration electronic health record data (n=669). Multivariable logistic regression models tested for associations of GWI with self-reported ASCVD, diabetes, hyperlipidemia, and hypertension, controlling for confounding factors. Separate models tested for GWI associations with ASCVD and risk factors documented in the electronic health record. GWI was associated with self-reported hypertension (adjusted odds ratio [aOR], 1.67 [95% CI, 1.18-2.36]), hyperlipidemia (aOR, 1.46 [95% CI, 1.03-2.05]), and ASCVD (aOR, 2.65 [95% CI, 1.56-4.51]). In the subset of veterans with electronic health record data, GWI was associated with documented diabetes (aOR, 2.34 [95% CI, 1.43-3.82]) and hypertension (aOR, 2.84 [95% CI, 1.92-4.20]). Hyperlipidemia and hypertension served as partial mediators of the association between GWI and self-reported ASCVD.

CONCLUSIONS

Gulf War veterans with GWI had higher odds of hyperlipidemia, hypertension, diabetes, and ASCVD compared with Gulf War veterans without GWI. Further examination of the mechanisms underlying this association, including a possible shared exposure-related mechanism, is necessary.

Pyridostigmine Bromide Pills and Pesticides Exposure as Risk Factors for Eye Disease in Gulf War Veterans

To examine associations between the pyridostigmine bromide (PB) pill and/or pesticide exposure during the 1990-1991 Gulf War (GW) and eye findings years after deployment. A cross-sectional study of South Florida veterans who were deployed on active duty during the GW Era (GWE). Information on GW exposures and ocular surface symptoms were collected via standardized questionnaires and an ocular surface examination was performed. Participants underwent spectral domain-ocular coherence tomography (SD-OCT) imaging that included retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and macular maps. We examined for differences in eye findings between individuals exposed versus not exposed to PB pills or pesticides during service. A total of 40.7% (n = 44) of individuals reported exposure to PB pills and 41.7% (n = 45) to pesticides; additionally, 24 reported exposure to both in the GW arena. Demographics were comparable across groups. Individuals exposed to PB pills reported higher dry eye (DE) symptoms scores (the 5-Item Dry Eye Questionnaire, DEQ-5: 9.3 ± 5.3 vs. 7.3 ± 4.7, p = 0.04) and more intense ocular pain (average over the last week: 2.4 ± 2.6 vs. 1.5 ± 1.8, p = 0.03; Neuropathic Pain Symptom Inventory modified for the Eye (NPSI-E): 18.2 ± 20.0 vs. 10.8 ± 13.8, p = 0.03) compared to their non-exposed counterparts. DE signs were comparable between the groups. Individuals exposed to PB pills also had thicker OCT measurements, with the largest difference in the outer temporal segment of the macula (268.5 ± 22.2 μm vs. 260.6 ± 14.5 μm, p = 0.03) compared to non-exposed individuals. These differences remained significant when examined in multivariable models that included demographics and deployment history. Individuals exposed to pesticides had higher neuropathic ocular pain scores (NPSI-E: 17.1 ± 21.1 vs. 11.6 ± 12.9, p = 0.049), but this difference did not remain significant in a multivariable model. Individuals exposed to PB pills during the GWE reported more severe ocular surface symptoms and had thicker OCT measures years after deployment compared to their non-exposed counterparts.

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.