Sex Differences in Cardiovascular Disease Outcomes After Traumatic Brain Injury

BACKGROUND: 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. OBJECTIVES: As emerging evidence indicates that men and women have different outcomes after TBI, we sought to describe CVD risk after TBI stratified by sex. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.