Giant cell arteritis and inflammatory bowel disease - Is there a connection? Results from a population-based study

Giant cell arteritis (GCA) is an autoimmune disorder which primarily affects large vessels, whilst inflammatory bowel diseases (IBD) mainly target the gut. Co-existence of the two maladies has been reported sporadically in the literature; therefore the purpose of this study was to assess the authenticity of such an association in a large, cross-sectional study.

Utilizing data derived from the Clalit Health Services' registry, the largest health maintenance organization in Israel, we compared the proportion of CD and UC in GCA patients with age- and gender-matched controls. Univariate analysis was performed using Chi-square and student t-test and a multivariate analysis was performed using a logistic regression model.

The study included 3938 GCA patients and 21,623 age- and gender-matched controls. GCA patients had a significantly increased proportion of both CD and UC in comparison with controls (0.79% vs. 0.12% and 0.84% vs. 0.21%, P-value < .001, respectively). The strength of the association between GCA and IBD was negatively correlated with the patients' age; thus the association was more robust amongst middle-aged patients (ages 50-69, OR = 8.13) than in elderly patients (ages 70-85, OR = 3.81). The association between GCA and IBD remained significant when evaluated independently of confounding factors (OR = 2.63, P-value < .001).

The probability that GCA patients also suffer from IBD is increased in comparison with age- and gender-matched controls. Our findings indicate that this association is more prominent in middle-aged patients (50-69 years of age). Screening for IBD amongst GCA patients in this age group may be warranted.