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

Spirometric Pulmonary Restriction in Herbicide-Exposed U.S. Vietnam War Veterans.

Spirometric restriction in herbicide-exposed U.S. Army Chemical Corps Vietnam War veterans was examined because no published research on this topic in Vietnam War veterans exists. Spirometry was conducted on 468 veterans who served in chemical operations in a 2013 study assessing the association between chronic obstructive pulmonary disease (COPD) and herbicide exposure. Exposure was verified based on blood serum values of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Further, the association between herbicide exposure and spirometry restriction (forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ≥ lower limit of normal (LLN) and FVC < LLN) was tested after adjustment for military characteristics, selected anthropometrics, and other predictors using multivariable regression. Spirometric restriction in herbicide sprayers (15.7%, 95% CI: 10.6, 20.9) was almost twice that of nonsprayers (9.91%, 95% CI: 5.9, 13.9) (p = 0.081). While spirometric restriction was not significantly associated with herbicide exposure (adjusted odds ratio (aOR) = 1.64, 95% CI: 0.82, 3.29) despite the greater prevalence of restriction in sprayers versus nonsprayers, spirometric restriction was significantly associated with race/ethnicity (aOR = 3.04, 95% CI: 1.36, 6.79) and waist circumference (aOR = 2.46, 95% CI: 1.25, 4.85). Because restrictive pulmonary disease may result from chemically-induced inflammation or sensitivity, research on chemical exposures and restriction in veterans should continue. Future study should include full pulmonary function testing, targeted research designs, and a wider set of explanatory variables in analysis, such as other determinants of health.

Herbicide Exposure, Vietnam Service, and Hypertension Risk in Army Chemical Corps Veterans.

OBJECTIVE: We examined hypertension risk in Army Chemical Corps (ACC) veterans who sprayed defoliant in Vietnam. METHODS: We analyzed data from the 2013 health survey of 3086 ACC veterans and investigated the association between self-reported physician-diagnosed-hypertension (SRH) and herbicide-spray-history adjusting for Vietnam-service-status, rank, age, tobacco/alcohol use, race, and body mass index (BMI). Spray-history was verified against serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (n = 636). SRH was confirmed by blood pressure (BP) measurement by trained medical technicians and medical record reviews. RESULTS: Herbicide-spray-history (ORadjusted[95%confidence interval {CI}] = 1.74[1.44,2.11]) and Vietnam-service-status (ORadjusted = 1.26[1.05,1.53]) were significantly associated with SRH. The association was highest when comparing Vietnam-service-sprayers to non-Vietnam-service-nonsprayers (ORadjusted = 2.21[1.76,2.77]). Serum TCDD was highest for Vietnam-service-sprayers. Mean systolic BPs were significantly higher among veterans with SRH than those without (P ≤ 0.001). Medical records and SRH overall agreement was 89%. CONCLUSION: Occupational herbicide exposure history and Vietnam-service-status were significantly associated with hypertension risk.