Objectives: Patients with inflammatory bowel disease (IBD) present with several extraintestinal manifestations, including systemic inflammation and hypercoagulability. Limited studies have shown that patients with IBD may have a higher risk of developing atherosclerosis. The incidence of coronary artery disease (CAD) and the role of traditional CAD risk factors in IBD patients remain unclear. We sought to compare the rates of CAD events in patients with IBD with matched controls.
Methods: We performed a longitudinal cohort study of patients with IBD compared with matched controls. The primary outcome was the development of CAD events. Traditional and nontraditional CAD risk factors were assessed. Cox proportional hazards model was used to assess the impact of each CAD risk factor on the outcomes.
Results: A total of 356 IBD patients and 712 matched controls were followed for a median of 53 and 51 months, respectively. The unadjusted hazard ratio (HR) for developing CAD in the IBD group was 2.85 (95% confidence interval (CI) 1.82-4.46). IBD patients had significantly lower rates of selected traditional CAD risk factors (hypertension, diabetes, dyslipidemia, and obesity; P<0.01 for all). Adjusting for these factors, the HR for developing CAD between groups was 4.08 (95% CI 2.49-6.70). Among nontraditional risk factors, an elevated white blood cell (WBC) count was a risk factor for CAD development in the IBD group (HR 1.23; 95% CI 1.15-1.33).
Conclusions: An increased incidence of CAD events was noted in IBD patients despite having a lower burden of traditional risk factors. Additionally, these risk factors had a lower impact on CAD development in the IBD group. Further investigation into how nontraditional risk factors, including WBC count, and the effect of attenuating systemic inflammation in IBD patients change CAD risk is warranted.