Prevalence of and Risk Factors for Autopsy-Determined Atherosclerosis Among US Service Members, 2001-2011

Abstract

Autopsies of US service members killed in the Korean and Vietnam wars demonstrated that atherosclerotic changes in the coronary arteries can appear early in the second and third decades of life, long before ischemic heart disease becomes clinically apparent. To estimate the current prevalence of coronary and aortic atherosclerosis in the US armed forces. Cross-sectional study of all US service members who died of combat or unintentional injuries in support of Operations Enduring Freedom and Iraqi Freedom/New Dawn between October 2001 and August 2011 and whose cardiovascular autopsy reports were available at the time of data collection in January 2012. Prevalence of atherosclerosis was analyzed by various demographic characteristics and medical history. Classifications of coronary atherosclerosis severity were determined prior to data analysis and designed to provide consistency with previous military studies: minimal (fatty streaking only), moderate (10%-49% luminal narrowing of ≥1 vessel), and severe (≥50% narrowing of ≥1 vessel). Prevalence of coronary and aortic atherosclerosis in the US armed forces and by age, sex, self-reported race/ethnicity, education, occupation, service branch and component, military rank, body mass index at military entrance, and International Classification of Diseases, Ninth Revision, Clinical Modification, diagnoses of cardiovascular risk factors. Of the 3832 service members included in the analysis, the mean age was 25.9 years (range, 18-59 years) and 98.3% were male. The prevalence of any coronary atherosclerosis was 8.5% (95% CI, 7.6%-9.4%); severe coronary atherosclerosis was present in 2.3% (95% CI, 1.8%-2.7%), moderate in 4.7% (95% CI, 4.0%-5.3%), and minimal in 1.5% (95% CI, 1.1%-1.9%). Service members with atherosclerosis were significantly older (mean [SD] age, 30.5 [8.1] years) than those without (mean [SD] age, 25.3 [5.6] years; P < .001). Comparing atherosclerosis prevalence among with those with no cardiovascular risk factor diagnoses (11.1% [95% CI, 10.1%-12.1%]), there was a greater prevalence among those with a diagnosis of dyslipidemia (50.0% [95% CI, 30.3%-69.7%]; age-adjusted prevalence ratio [PR], 2.09 [95% CI, 1.43-3.06]), hypertension (43.6% [95% CI, 27.3%-59.9%]; age-adjusted PR, 1.88 [95% CI, 1.34-2.65]), or obesity (22.3% [95% CI, 15.9%-28.7%]; age-adjusted PR, 1.47 [95% CI, 1.10-1.96]), but smoking (14.1% [95% CI, 8.0%-20.2%]) was not significantly associated with a higher prevalence of atherosclerosis (age-adjusted PR, 1.12 [95% CI, 0.73-1.74]). Among deployed US service members who died of combat or unintentional injuries and received autopsies, the prevalence of atherosclerosis varied by age and cardiovascular risk factors.