Introduction: Previous studies suggest an increased risk of adverse cardiovascular (CV) outcomes among individuals with inflammatory bowel disease (IBD). This increased risk is observed in the absence of traditional CV risk factors such that younger (< 40-50 years) and female individuals with IBD are observed to be at higher risk of coronary heart disease and stroke than their non-IBD counterparts. The risk of adverse CV outcomes specifically among older postmenopausal women with IBD is unclear.
Methods: We performed a survival analysis of participants enrolled in the Women’s Health Initiative (WHI, 1993-2010). Participants in both the WHI clinical trials (hormone therapy, diet modification, calcium/vitamin D) and observational study were included. We excluded participants with missing data on self-reported IBD diagnosis at enrollment, missing model covariate data, no follow-up data, or a previous history of one of the CV outcomes of interest: coronary heart disease (CHD), ischemic stroke, venous thromboembolism (VTE), or peripheral arterial disease (PAD). We assessed the risk of each outcome between women with and without IBD using Cox proportional hazard models, stratified by WHI trial group and WHI follow-up period. Models were adjusted for age, socio-demographics and comorbidities (e.g. treated hypertension, diabetes, or hypercholesterolemia), as well as family history and lifestyle factors (e.g. smoking, alcohol, physical activity).
Results: Of the 134,022 women included in the study, IBD was reported at baseline in 1,367 (1.02%). The mean baseline age for women with and without IBD was 63 years. After adjusting for age and other potential confounders, no significant difference was observed in women with versus without IBD for the risk of CHD (HR 0.98, 95%CI 0.75-1.27), VTE (HR 1.13, 95%CI 0.82-1.55) or PAD (HR 0.65, 95%CI 0.29-1.47). After adjusting for age, the risk of ischemic stroke was significantly higher (HR 1.41, 95%CI 1.06-1.88) in women with compared to those without IBD. On further adjustment for socio-demographics, comorbidities, family history, and lifestyle factors, the increased risk of ischemic stroke among women with IBD remained statistically significant although attenuated (HR 1.34, 95%CI 1.00-1.80).
Discussion: Among post-menopausal women, risk of ischemic stroke may be increased in those with compared to those without IBD. Accounting for traditional CV risk factors, such as metabolic comorbidities and lifestyle may attenuate the risk.
