Risk of persistent cardiovascular conditions in the Deepwater Horizon Oil Spill Coast Guard Cohort during five years of follow-up

Abstract

Background/Aim: In 2010, nearly 9,000 U.S. Coast Guard (USCG) members led the clean-up response to the Deepwater Horizon (DWH) oil spill. To date, human studies evaluating persistent cardiovascular conditions associated with oil spill-related exposures are sparse. Thus, our aim was to prospectively evaluate risk of incident cardiovascular conditions among active-duty USCG DWH responders.Methods: Crude oil and oil dispersant exposures were ascertained via self-report from responders who completed post-deployment surveys. Cardiovascular outcomes, classified via International Classification of Diseases, 9th Edition (ICD-9), were queried from military health encounter records for responders and non-responders up to 5.5 years post-DWH. We used Cox proportional hazards regression to calculate adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) for cardiovascular conditions diagnosed during 2010-2012 and 2013-2015.Results: This cohort (N=42,721) was predominantly male (~86%), white (~77%), and younger than 35 (~71%). Compared to non-responders, responders had an elevated risk for mitral valve disorders (ICD-9: 424.0) during 2013-2015 (aHR=2.12, 95% CI=1.15-3.90). Compared to non-exposed responders, responders reporting crude oil exposure had a significantly higher risk for essential hypertension (ICD-9: 401) during 2010-2012 (aHR=1.68, 95% CI=1.15-2.44); for those reporting crude oil inhalation exposure, aHR was 1.46 (95% CI=1.02-2.11). Responders with crude oil inhalation exposure also had a significantly elevated risk for palpitations (ICD-9: 785.1) during 2013-2015 (aHR=2.54, 95% CI=1.36-4.74). Risk estimates for hypertension and palpitations were slightly stronger and remained significant for responders reporting exposure to both crude oil and oil dispersant versus those reporting neither (aHRs=1.91 and 2.87, respectively).Conclusions: This study of healthy military members with equal healthcare access indicates that oil spill exposures may be associated with incident cardiovascular conditions.Disclaimer: The contents, views or opinions expressed in this presentation are those of the authors and do not necessarily reflect official policy or position of USU, the Department of Defense, or the USCG.