Autopsy study highlights dramatic decline in atherosclerosis among US soldiers
The prevalence of coronary atherosclerosis among deployed US service members who died during the past decade is 8.5%, which is markedly lower than rates observed in soldiers who served in the Korean and Vietnam wars. Researchers, however, remain uncertain about the drivers behind this decrease.
“This prevalence demonstrates a steep decline from the rates of 77% noted in the Korean War and 45% in the Vietnam War — a decline that can be explained by either real or artifactual phenomena,” researchers wrote in JAMA.
Bryant J. Webber, MD, of the Uniformed Services University of the Health Sciences in Bethesda, Md., and colleagues conducted a study of 3,832 (mean age, 25.9 years; 98.3% men) members of the armed forces with available CV autopsy reports who died from combat-related or unintentional injuries in support of Operation Enduring Freedom and Operation Iraqi Freedom/New Dawn between 2001 and 2011. Coronary atherosclerosis was classified as minimal (fatty streaking only), moderate (10% to 49% luminal narrowing of ≥1 vessel) and severe (≥50% narrowing of ≥1 vessel).
Prevalence of any coronary atherosclerosis was 8.5% (95% CI, 7.6-9.4); severe coronary atherosclerosis, 2.3% (95% CI, 1.8-2.7); moderate, 4.7% (95% CI, 4-5.3); and minimal, 1.5% (95% CI, 1.1-1.9). The researchers found that age was most strongly associated with prevalence of atherosclerosis. Service members with atherosclerosis were older than those without (30.5 years vs. 25.3 years; P<.001). Further, prevalence of atherosclerosis appeared to be approximately seven times higher in those aged at least 40 years vs. those aged 24 years or younger (45.9% vs. 6.6%).
Data also indicated that, compared with service members without CV risk factors (11.1%), prevalence of atherosclerosis was greater among those with a diagnosis of dyslipidemia (50%), hypertension (43.6%) or obesity (22.3%). Lower education level and higher military entrance BMI were linked to higher prevalence as well. Smoking, however, was not significantly associated with increased prevalence.
Although these results are encouraging, the researchers cautioned against comparing this study with previous studies involving those who served in the Korean and Vietnam wars for several reasons. For example, they said different methods for measuring atherosclerosis were used and selection bias may have been caused by voluntary vs. conscripted military service.
In an accompanying editorial, Daniel Levy, MD, of the National Heart, Lung, and Blood Institute, highlighted these issues but also said these autopsy studies show that coronary disease begins at a young age and primary prevention is key.
“Declines in cardiovascular disease risk factors have almost certainly contributed to the observed reductions in prevalence of subclinical atherosclerosis, incidence of clinical atherosclerotic disease, and deaths from heart disease,” he wrote. “Although age-adjusted heart disease death rates have declined by 72% since their peak during the Vietnam War years, cardiovascular disease remains the leading cause of death in the United States. The national battle against heart disease is not over; increasing rates of obesity and diabetes signal a need to engage earlier and with greater intensity in a campaign of pre-emption and prevention.”
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Disclosure: The researchers report no relevant financial disclosures. Levy reports no relevant financial disclosures.