Agent orange exposure and prostate cancer risk in the million veteran program.

BACKGROUND: The US government considers veterans to have been exposed to Agent Orange if they served in Vietnam while the carcinogen was in use, and these veterans are often deemed at high risk of prostate cancer (PCa). Here, we assess whether presumed Agent Orange exposure is independently associated with increased risk of any metastatic or fatal PCa in a diverse Veteran cohort still alive in the modern era (at least 2011), when accounting for race/ethnicity, family history, and genetic risk. PATIENTS AND METHODS: Participants in the Million Veteran Program (MVP; enrollment began in 2011) who were on active duty during the Vietnam War era (August 1964-April 1975) were included (n = 301,470). Agent Orange exposure was determined using the US government definition. Genetic risk was assessed via a validated polygenic hazard score. Associations with age at diagnosis of any PCa, metastatic PCa, and death from PCa were assessed via Cox proportional hazards models. RESULTS AND INTERPRETATION: On univariable analysis, exposure to Agent Orange was not associated with increased PCa (hazard ratio [HR]: 1.02, 95% confidence interval [CI]: 1.00-1.04, p = 0.06), metastatic PCa (HR: 0.98, 95% CI: 0.91-1.05, p = 0.55), or fatal PCa (HR: 0.94, 95% CI: 0.79-1.09, p = 0.41). When accounting for race/ethnicity and family history, Agent Orange exposure was independently associated with slightly increased risk of PCa (HR: 1.06, 95% CI: 1.04-1.09, <10-6) but not with metastatic PCa (HR: 1.07, 95% CI: 0.98-1.15, p = 0.10) or PCa death (HR: 1.02, 95% CI: 0.83-1.23, p = 0.09). Similar results were found when accounting for genetic risk. Agent Orange exposure history may not improve modern PCa risk stratification.

Mortality of Women Vietnam War-Era Veterans.

PURPOSE: Our objectives were to 1) understand the scope of the current mortality literature on U.S. women Vietnam War-era veterans and 2) identify major themes and knowledge gaps that might guide future research. METHODS: A systematic scoping review was conducted. Electronic bibliographic databases were searched for studies published on women Vietnam War-era veterans' mortality between 1973 and 2020. Inclusion and exclusion criteria were applied, study information was charted using pre-established design parameters, and studies deemed eligible were retained for a more in-depth review. FINDINGS: One hundred nineteen studies were initially identified. Of these, six were ultimately retained for critical review. External cause, all-cause, cancer, and cardiovascular mortality were prominent outcomes across studies. Although both methodology and outcomes varied by study, unifying themes emerged. Prominent themes included a) historic barriers to accurately identifying and classifying this veteran cohort, b) historic barriers to comprehensive assessment of their health and mortality risk, and c) the healthy soldier effect and its limitations. Research gaps identified in this review reflect a need to pay more attention to sex differences in mortality risk and military occupational and sex-specific health risk confounders in mortality models. CONCLUSIONS: The research literature examining mortality among women Vietnam War-era veterans is circumscribed in size and scope. Questions about the roles of salient military occupational exposures and health risk factors on mortality risks and trends in this cohort remain unaddressed. These questions should be areas of focus in next steps research.

Investigation of C-reactive protein and AIM2 methylation as a marker for PTSD in Australian Vietnam veterans.

Chronic inflammation is a key factor in symptomology and comorbidities of post-traumatic stress disorder (PTSD). Levels of a proinflammatory marker, C-reactive protein (CRP) are increased in individuals with PTSD but it is not clear if this is due to trauma exposure or PTSD. Our study aimed to assess the relationship between serum CRP levels, CRP SNPs, methylation, mRNA expression and PTSD in a homogenous trauma exposed Australian Vietnam veteran cohort. We hypothesized that decreased DNA methylation would be associated with increased gene expression and increased peripheral CRP levels in PTSD patients and that this would be independent of trauma. Participants were 299 Vietnam veterans who had all been exposed to trauma and approximately half were diagnosed with PTSD. We observed higher levels of serum CRP in the PTSD group compared to the non-PTSD group but after controlling for BMI and triglycerides the association did not remain significant. No association was found between CRP SNPs and PTSD or CRP levels. Absent in Melanoma 2 (AIM2) which is a mediator of inflammatory response and a determinant of CRP levels was analysed for DNA methylation and mRNA expression. We observed a trend level association between PTSD and AIM2 methylation after controlling for age, smoking, triglycerides, BMI and cell types. There was no significant interaction between PTSD and CRP levels on AIM2 methylation after controlling for covariates. We observed that as AIM2 methylation levels decreased, AIM2 mRNA expression increased. Elevated CRP levels were associated with AIM2 mRNA in the trauma exposed cohort but there was no significant interaction effect with PTSD. Our results could not confirm that CRP is a marker of PTSD independent of trauma in this group of older veterans. CRP may be a broad marker of disease risk, or a marker of PTSD in younger cohorts than those in this study.

Agent Orange Exposure and Dementia Diagnosis in US Veterans of the Vietnam Era.

Importance: Agent Orange is a powerful herbicide that contains dioxin and was used during the Vietnam War. Although prior studies have found that Agent Orange exposure is associated with increased risk of a wide range of conditions, including neurologic disorders (eg, Parkinson disease), metabolic disorders (eg, type 2 diabetes), and systemic amyloidosis, the association between Agent Orange and dementia remains unclear. Objective: To examine the association between Agent Orange exposure and incident dementia diagnosis in US veterans of the Vietnam era. Design, Setting, and Participants: This cohort study included Veterans Health Administration data from October 1, 2001, and September 30, 2015, with up to 14 years of follow-up. Analyses were performed from July 2018 to October 2020. A 2% random sample of US veterans of the Vietnam era who received inpatient or outpatient Veterans Health Administration care, excluding those with dementia at baseline, those without follow-up visits, and those with unclear Agent Orange exposure status. Exposures: Presumed Agent Orange exposure documented in electronic health record. Main Outcomes and Measures: Fine-Gray competing risk models were used to compare the time to dementia diagnosis (with age as the time scale) for veterans with vs without presumed Agent Orange exposure (as per medical records), adjusting for demographic variables and medical and psychiatric comorbidities. Results: The total sample was 511 189 individuals; after exclusions, 316 351 were included in analyses. Veterans were mostly male (n = 309 889 [98.0%]) and had a mean (SD) age of 62 (6.6) years; 38 121 (12.1%) had presumed Agent Orange exposure. Prevalence of most conditions, including Parkinson disease, diabetes, and amyloidosis, was similar at baseline among veterans with and without Agent Orange exposure. After adjusting for demographic variables and comorbidities, veterans exposed to Agent Orange were nearly twice as likely as those not exposed to receive a dementia diagnosis over a mean (SD) of 5.5 (3.8) years of follow-up (1918 of 38 121 [5.0%] vs 6886 of 278 230 [2.5%]; adjusted hazard ratio: 1.68 [95% CI, 1.59-1.77]). Veterans with Agent Orange exposure developed dementia at a mean of 1.25 years earlier (at a mean [SD] age of 67.5 [7.0] vs 68.8 [8.0] years). Conclusions and Relevance: Veterans with Agent Orange exposure were nearly twice as likely to be diagnosed with dementia, even after adjusting for the competing risk of death, demographic variables, and medical and psychiatric comorbidities. Additional studies are needed to examine potential mechanisms underlying the association between Agent Orange exposure and dementia.

Serum dioxin levels and sperm DNA methylation age: Findings in Vietnam war veterans exposed to Agent Orange.

Exposure to dioxin, a known endocrine disruptor and carcinogen, is associated with poor reproductive outcomes. Yet, few studies have explored the role of DNA methylation in these relationships. Utilizing a publicly available dataset from 37 male Air Force Health Study participants exposed to dioxin-contaminated Agent Orange during the Vietnam war, we cross-sectionally examined the relationship of serum dioxin levels with a novel DNA methylation-based measure of sperm age (DNAm-agesperm). DNAm-agesperm was calculated using CpG sites on the Illumina HumanMethylation450 BeadChip. We estimated associations of dioxin levels with DNAm-agesperm using linear regression models adjusted for chronological age, body mass index, and smoking status. Chronological age was highly correlated with DNAmagesperm (r = 0.80). In fully-adjusted linear models, a one percent increase in serum dioxin levels was significantly associated with a 0.0126-year (i.e. 4.6-day) increase in DNAm-agesperm (95%CI: 0.003, 0.022, p = 0.01). Further analyses demonstrated significant negative associations of dioxin levels (ß = -0.0005, 95%CI: -0.0010, 0.00004, P = 0.03) and DNAm-agesperm (ß = -0.02, 95%CI: -0.04, -0.001, P = 0.03) with methylation levels of FOXK2 - a gene previously reported to be hypomethylated in infertile men. In sum, we demonstrate associations of dioxin with increased methylation aging of sperm. DNAm-agesperm may provide utility for understanding how dioxin levels impact sperm health and potentially male reproductive capacity in human population studies. Moreover, our pilot study contributes further evidence that some environmental toxicants are associated with methylation aging. Additional studies are necessary to confirm these findings, and better characterize dioxin and sperm methylation relationships with male reproductive health.

Increased risk of head and neck cancer in Agent Orange exposed Vietnam Era veterans.

IMPORTANCE: United States military personnel during the Vietnam Era were potentially exposed to Agent Orange, a known carcinogen. The link between Agent Orange and head and neck cancers is largely unknown; laryngeal cancer is currently the only subsite with sufficient evidence of an Agent Orange association. OBJECTIVE: We aim to determine the relationship between Agent Orange exposure and the incidence of head and neck cancers in Vietnam Era veterans as well as any relationship with head and neck cancer survival. MATERIALS AND METHODS: The present study utilizes the Veterans Affairs Corporate Data Warehouse (VA CDW) to identify Vietnam Era veterans, their Agent Orange exposure status, limited demographic data, presence of head and neck cancer, and survival data. RESULTS: Of 8,877,971 Vietnam Era veterans, 22% self-reported exposure to Agent Orange, and 54,717 had a diagnosis of head and neck cancer. Agent Orange exposure significantly predicted upper aerodigestive tract carcinoma, with a relative risk (RR) of 1.10. On subsite analysis, Agent Orange exposure (as well as race, gender, and substance use) was significantly associated with oropharyngeal (RR 1.16), nasopharyngeal (RR 1.22), laryngeal (1.11), and thyroid (1.24) cancers. Agent Orange exposure was associated with improved 10-year overall survival in upper aerodigestive tract cancer patients. CONCLUSIONS AND RELEVANCE: Self-reported Agent Orange exposure correlated with increased risks of oropharyngeal, nasopharyngeal, laryngeal, and thyroid cancers, and predicted improved survival in upper aerodigestive tract cancer patients. These findings broaden our understanding of the risks of Agent Orange exposure.

Self-reported physician-diagnosed chronic obstructive pulmonary disease and spirometry patterns in Vietnam Era US Army Chemical Corps veterans: A retrospective cohort study.

BACKGROUND: Research on chronic obstructive pulmonary disease (COPD) and herbicide exposure in Vietnam War veterans is limited. METHODS: Survey data were collected from 3193 US Army Chemical Corps veterans on herbicide exposure and self-reported physician-diagnosed COPD. Three spirometric patterns were used to define airflow obstruction (AFO): (i) FEV1 /FVC < 70% ("fixed ratio"); (ii) FEV1 /FVC < lower limit of normal ("LLN"); and (iii) (FEV1 /FVC < LLN and FVC ≥ LLN and FEV1

Cancer patterns in Hmong in Minnesota, 2000 to 2012.

BACKGROUND: Minnesota has the second largest Hmong population in the United States. The objective of the current study was to estimate the cancer incidence among Hmong individuals in Minnesota between 2000 and 2012 to determine targets for screening and interventions. METHODS: Cancer cases in Minnesota between 2000 and 2012 were obtained from the Minnesota Cancer Surveillance System, and proportional incidence ratios (PIRs) were calculated. The 2000 and 2010 US Census reports were used to obtain total population estimates. Age-adjusted cancer incidence rates (AAR) and 95% confidence intervals (95% CIs) were calculated for Hmong individuals, Asian/Pacific Islander individuals, and all Minnesotans using direct method and Poisson regression. RESULTS: Compared with all Minnesotans, the Hmong had elevated PIRs and AARs for malignancies related to infections, including nasopharyngeal, stomach, liver, and cervical cancers. The AAR ratios in Hmong versus all Minnesotans were found to be significantly increased for nasopharyngeal (AAR, 15.90; 95% CI, 9.48-26.68), stomach (AAR, 2.99; 95% CI, 2.06-4.33), liver (AAR, 1.77; 95% CI, 1.04-3.02), and cervical (AAR, 3.88; 95% CI, 2.61-5.77) cancers. The AARs in Hmong versus all Minnesotans were significantly lower for all-cause cancer (AAR, 0.39; 95% CI, 0.35-0.44); cancers of the breast, lung, and colorectum; melanoma; and non-Hodgkin lymphoma. Compared with Asian/Pacific Islander individuals, the rates in Hmong were significantly higher for melanoma and cervical cancer, with AAR ratios of 2.23 (95% CI, 1.09-4.56) and 1.59 (95% CI, 1.01-2.49), respectively. CONCLUSIONS: Compared with all Minnesotans, the Hmong have an increased incidence of cancers related to infectious agents. These findings indicate a need for cancer prevention and screening programs in this population.

Unrealized potential of the US military battlefield trauma system: DOW rate is higher in Iraq and Afghanistan than in Vietnam, but CFR and KIA rate are lower.

LEVEL OF EVIDENCE: Observational/retrospective/historic controls, level IV.

Combat, Posttraumatic Stress Disorder, and Smoking Trajectory in a Cohort of Male Australian Army Vietnam Veterans.

Background: Whether trauma exposure itself or consequent posttraumatic stress disorder (PTSD) is primarily responsible for smoking and failure to quit remains unclear. Methods: A cohort of male Australian Vietnam veterans (N = 388) was interviewed twice, 22 and 36 years after their return to Australia using standardized psychiatric diagnostic and health interviews and assessment of combat exposure. The smoking trajectory over time revealed a spectrum of outcomes (never smoked, early quitters, late quitters, and continuing smokers). Analysis used multivariate statistics to assess the relative contributions of combat trauma exposure and PTSD while controlling for potential confounders. Results: The trajectory of smoking over time revealed that 21.9% of veterans had never smoked, 45.1% had quit smoking by the time of wave 1, 16.2% were current smokers at wave 1 who had quit by the time of wave 2, 2.8% were late adopters who were current smokers, and 13.9% were continuing smokers. Smoking was associated in single-predictor models with demographics, intelligence, combat exposure, PTSD symptom clusters and diagnosis, and alcohol disorders. Multivariate analysis revealed that PTSD, combat, and intelligence were related to the smoking spectrum but, after adding demographics and other Axis I psychiatric diagnoses, only combat remained significant. No PTSD symptom cluster uniquely predicted smoking status. Conclusions: The results suggest that trauma exposure in the form of military combat may be a more robust predictor of smoking status over time than PTSD. It may be stress itself, rather than poststress disorder, that is more germane to smoking and failure to quit. Implications: Exposure to traumatic stress and development of PTSD have been implicated separately in the maintenance of smoking. This longitudinal cohort study of smoking in war veterans up to three decades postwar enabled evaluation of traumatic stress exposure in combat and the course of PTSD in smoking and quitting while controlling for intelligence, background disadvantage, and other psychiatric conditions. Combat rather than PTSD emerged as more significant to smoking status, suggesting that it may be the traumatic stress itself rather than the development of a poststress disorder that is more germane to smoking in war veterans.

Expression of aryl hydrocarbon receptor, inflammatory cytokines, and incidence of rheumatoid arthritis in Vietnamese dioxin-exposed people.

Many Vietnamese citizens have been and continue to be inadvertently exposed to dioxins and dioxin-like compounds deposited in the country during the Vietnam War. Dioxins may be involved in the pathogenesis of inflammatory diseases in part via by affecting expression of aryl hydrocarbon receptor (Ahr) and inflammatory cytokines in animal models. As the role of the Ahr in dioxin-exposed people is not well defined, a study was conducted to examine gene expression levels of Ahr, inflammatory cytokines, and the incidence of diseases in dioxin-exposed citizens who had/still resided near a heavily dioxin-contaminated area in Vietnam. Whole blood from citizens at/around Da Nang airbase and control individuals living in unsprayed areas was collected. Serum levels of dioxins were analyzed by using a dioxins-responsive chemical-activated luciferase gene expression bioassay. Gene expression of Ahr, interleukin (IL)-1ß, TNFα, IL-6, and IL-22 in whole blood was examined by quantitative real-time PCR. The results showed levels of dioxins and expression of Ahr, IL-1ß, TNFα, and IL-6 were up-regulated while IL-22 expression was down-regulated in dioxin-exposed people. Various disease incidences in the study subjects was also examined. Interestingly, the incidence of rheumatoid arthritis (RA) in these individuals was increased compared to the estimated prevalence of this disease in the general Vietnamese population. Analyses also showed that expression levels of Ahr correlated to those of IL-6 and IL-22 in the dioxin-exposed people. Taken together, dioxins might be involved in an up-regulated expression of Ahr that might possibly relate to changes in level of inflammatory cytokines and, ultimately, in the incidence of select diseases in residents of Vietnam who had/continue to live near a dioxins-contaminated site.

Exploring exposure to Agent Orange and increased mortality due to bladder cancer.

BACKGROUND: During the Vietnam War, many veterans were exposed to Agent Orange (AO), a chemical defoliant containing varying levels of the carcinogen dioxin. The health effects of AO exposure have been widely studied in the VA population. Here we review and interpret data regarding the association between AO exposure and bladder cancer (BC) mortality. MAIN FINDINGS: Data evaluating the association between AO and BC is limited. Methods characterizing exposure have become more sophisticated over time. Several studies support the link between AO exposure and increased mortality due to BC, including the Korean Veterans Health Study. CONCLUSIONS: Available data suggest an association with exposure to AO and increased mortality due to BC. In patients exposed to AO, increased frequency of cystoscopic surveillance and potentially more aggressive therapy for those with BC may be warranted but utility of these strategies remains to be proven. Additional research is required to better understand the relationship between AO and BC.

Genetic and serum biomarker evidence for a relationship between TNFα and PTSD in Vietnam war combat veterans.

BACKGROUND: Posttraumatic stress disorder (PTSD) is associated with increased inflammation and comorbid medical conditions. However, study findings for individual inflammatory marker levels have been inconsistent. Some research suggests that resilience may play a role in decreased inflammation. A polymorphism in the promoter region of the tumor necrosis factor α gene (TNFα), TNFA -308 (rs1800629) is associated with psychiatric illness but its role in PTSD is yet to be elucidated. OBJECTIVE: This study investigates a key inflammatory marker, TNFα, for its role in PTSD severity. METHOD: In a cohort of trauma-exposed Vietnam War veterans (n=299; 159 cases, 140 controls) TNF α serum levels and TNFα polymorphism rs1800629 were correlated with PTSD severity and resilience scores. RESULTS: The polymorphism was associated with PTSD severity (p=0.045). There were significant group differences between cases and controls with regards to serum TNFα levels (p=0.036). Significant correlations were found between PTSD severity and elevated TNFα levels (r=0.153; p=0.009), and between resilience and decreased TNFα levels at a trend level (p=0.08) across the entire cohort. These relationships were non-significant after controlling for covariates. In the PTSD diagnostic group, a correlation of TNFα and PTSD severity was observed on a trend level (p=0.06), the relationship between TNFα and resilience remained non-significant. CONCLUSIONS: To our knowledge, this is the first time rs1800629 has been investigated in PTSD contributing to a growing body of literature that identifies the GG as a risk genotype for psychiatric disorders in Caucasian cohorts. However, more research is needed to replicate our results in larger, equally well-characterized cohorts. The relationship between serum TNFα levels and PTSD severity and resilience requires further investigation.