Sex Differences in Cardiovascular Disease Outcomes After Traumatic Brain Injury

TL;DR

This study shows that women who experience traumatic brain injury face a higher risk of cardiovascular disease compared to men, despite having lower overall CVD rates.

Contribution

The study reveals sex-specific differences in cardiovascular disease risk after traumatic brain injury in a large military cohort.

Findings

Women with TBI had higher hazard ratios for CVD compared to men across all TBI severity levels.

CVD was less prevalent in women overall, but TBI significantly increased their CVD risk.

The study highlights the need for sex-specific approaches in long-term care for TBI survivors.

Abstract

We previously demonstrated that traumatic brain injury (TBI) is associated with an increased risk of cardiovascular disease (CVD) in a large cohort of post-9/11 service members and veterans.

As emerging evidence indicates that men and women have different outcomes after TBI, we sought to describe CVD risk after TBI stratified by sex.

Data were obtained from the Long-term Impact of Military-Relevant Brain Injury Consortium-Chronic Effects of Neurotrauma Consortium Phenotype study. The cohort was divided into 2 subgroups: men and women. The primary outcome of interest was CVD defined as a composite of coronary artery disease, stroke, peripheral artery disease, and CVD mortality defined by International Classification of Diseases diagnosis codes. We performed Fine-Gray competing risks analyses to determine the association of TBI severity with subsequent CVD.

The study cohort consisted of N = 1,277,430 men and N = 282,498 women, with TBI prevalence of 20.8% and 12.7%, respectively. Men had a higher prevalence of CVD risk factors, and CVD was more prevalent in men (3.1%) compared to women (1.9%) (P < 0.001). In fully adjusted models, HRs and 95% CIs for CVD risk were higher in women than in men for all levels of TBI: HR for mild TBI in women: 2.09 (2.02-2.16) vs men: 1.62 (1.60-1.64); HR for moderate/severe TBI in women: 3.45 (3.34-3.56) vs men: 2.65 (2.62-2.69); HR for penetrating TBI among women: 5.61 (5.44-5.78) vs men 4.22 (4.17-4.27).

We found that while CVD is less common in women, TBI is associated with a larger risk for subsequent CVD in women. Future work is needed to determine the etiology of this association to improve long-term care given the increase in female service members in combat.

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