Risk Factors for the Occurrence and Severity of Vertebral Fractures in Inflammatory Bowel Disease Patients: A Nationwide Population-Based Cohort Study

Background: The risk of vertebral fractures is increased in inflammatory bowel disease (IBD) patients. However, whether the severity of vertebral fractures differs between IBD patients and the general population, or between patients with Crohn's disease (CD) and ulcerative colitis (UC), is unknown. Methods: We investigated risk factors associated with the occurrence and severity of vertebral fractures in IBD patients using The National Healthcare Insurance Service (NHIS) database. We defined the patients who underwent vertebroplasty or kyphoplasty after being diagnosed with a vertebral fracture as having a severe vertebral fracture than those with only diagnosis codes. Results: From 2008 to 2018, there were 33,778 patients with IBD (24,370 UC patients and 9,408 CD patients) and 101,265 patients in the reference population. The incidence rate ratio of vertebral fractures in the IBD patients was 1.27 per 1,000 person-years (95% confidence interval [CI], 1.26-1.27). The risk of vertebral fracture was higher in CD and UC patients than in the matched reference group (hazard ratio [HR], 1.59; 95% CI, 1.31-1.92; P < 0.001 and HR, 1.26; 95% CI, 1.14-1.41; P < 0.001, respectively). In a multivariate analysis, the occurrence of vertebral fracture was associated with CD (HR, 1.31; 95% CI, 1.08-1.59; P = 0.006), older age (CD: HR, 1.09; 95% CI, 1.08-1.09; P < 0.001 and UC: HR, 1.09; 95% CI, 1.08-1.09; P < 0.001), female sex (CD: HR, 1.81; 95% CI, 1.63-2.01; P < 0.001 and UC: HR, 2.02; 95% CI, 1.83-2.22; P < 0.001), high Charlson Comorbidity Index (CCI) score (CD: HR, 1.42; 95% CI, 1.23-1.63; P < 0.001 and UC: HR, 1.46; 95% CI, 1.29-1.65, P < 0.001), and long-term steroid use (CD: HR, 3.71; 95% CI, 2.84-3.37; P < 0.001 and UC: HR, 3.88; 95% CI, 3.07-4.91; P < 0.001). The severity of vertebral fractures was associated with IBD (CD: HR, 1.82; 95% CI, 1.17-2.83; P = 0.008 and UC: HR, 1.49; 95% CI, 1.17-1.89; P < 0.001) and older age (HR, 1.06; 95% CI, 1.05-1.07; P < 0.001). Conclusion: Vertebral fractures occur frequently and more severely in IBD patients, particularly those with CD. Therefore, we suggest monitoring of bone density, regular vitamin D supply, and reducing the use of corticosteroids to prevent vertebral fractures in IBD patients who are older, female, or have comorbidities.