Role of combat deployment-induced stress and newly-reported hypertension in the Millennium Cohort Study

Introduction: Hypertension affects nearly one-third of the US adult population and may lead to other serious conditions such as cardiovascular disease, stroke or renal failure. Combat deployments present unique stressors to military members. Although stress is postulated to increase blood pressure, little is known regarding a potential role in the development of acute or chronic hypertension. The current study examined the relationship between combat deployment-induced stress and newly-reported hypertension.

Methods: A representative sample of US military service members was invited to participate in a 21-year longitudinal study, the Millennium Cohort Study. A total of 77,047 participants completed the baseline questionnaire (July 2001 to June 2003), while 55,021 completed the first follow-up questionnaire (June 2004 to February 2006). Multivariable logistic regression was used to estimate the 3-year risk of new-onset hypertension, adjusting for general health, demographics, and occupational and behavioral characteristics.

Results: Newly-reported hypertension was identified in 6.9% of the cohort and 6.0% of deployers with combat exposures within the 3-year period. After adjusting for potential confounding, deployers reporting combat exposures were 1.28 times (95% confidence interval, 1.04-1.57) more likely to report incident hypertension compared with deployers not reporting combat exposures.

Conclusion: Deployment with reported stressful combat exposures appears to be a unique risk factor for new-onset self-reported hypertension even after adjusting for potential confounding factors. Future follow-up of this cohort may help to clarify the chronic nature of this condition. Additionally, studies to evaluate military deployment and hypertension diagnosis through blood pressure measurements are recommended.