The Association Between Inflammatory Bowel Disease (IBD) and Thyroid Disorders: Systematic Review

Abdullah Saleh Mohammed Alyami; Yasir Ali S  Al Murdhimah; Ahemd Hussain A  Al Abyah; Mohammed Hadi S  Al Baahharith; Ahmed Mohseen Y  Al Rashah; Ali Mohammed A  Al Murthimah; Shatha Abdulrahman m Almutairi; Faisal Hunaysh Abdullah  AlYami; Mohammed Ibrahim A  Al Makrami; Bader Mohamed A  Al-Obayiah; Nemer Nasser H  Al Mardef; Abdulrahman Mohammed M  Al Yassain

doi:10.54293/smhj.v6i1.174

Authors

Abdullah Saleh Mohammed Alyami Consultant-internal medicine, King Khalid Hospital, Najran, KSA.
Yasir Ali S Al Murdhimah Internal medicine resident, King Khalid Hospital, Najran, KSA.
Ahemd Hussain A Al Abyah Medical Intern Najran University Najran, KSA. https://orcid.org/0009-0001-8353-1274
Mohammed Hadi S Al Baahharith Medical Intern Najran University Najran, KSA. https://orcid.org/0009-0004-2811-6467
Ahmed Mohseen Y Al Rashah Medical intern Najran University Najran, KSA. https://orcid.org/0009-0007-0705-959X
Ali Mohammed A Al Murthimah Medical intern Najran University Najran, KSA. https://orcid.org/0009-0007-2530-9281
Shatha Abdulrahman m Almutairi 6th Year Medical Student, University of Jeddah, Jeddah, KSA.
Faisal Hunaysh Abdullah AlYami Medical Intern Najran University Najran, KSA. https://orcid.org/0009-0009-6489-8757
Mohammed Ibrahim A Al Makrami Medical Intern, Najran University, Najran, KSA. https://orcid.org/0009-0008-6544-8881
Bader Mohamed A Al-Obayiah ‏Medical intern,Najran University, ‏Najran , KSA.
Nemer Nasser H Al Mardef Medical intern Najran university Najran, KSA. https://orcid.org/0009-0005-7337-0461
Abdulrahman Mohammed M Al Yassain Medical intern, Najran University, Najran, KSA. https://orcid.org/0009-0004-0289-5458

DOI:

https://doi.org/10.54293/smhj.v6i1.174

Keywords:

Inflammatory bowel disease (IBD), Crohn’s disease, ulcerative colitis, thyroid disorders, hypothyroidism, thyroid cancer, autoimmunity, systematic review.

Abstract

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), is associated with various extraintestinal manifestations, including thyroid disorders. The relationship between IBD and thyroid dysfunction—such as hypothyroidism, hyperthyroidism, and thyroid cancer—remains unclear, with conflicting evidence on prevalence, risk factors, and underlying mechanisms. This systematic review followed PRISMA guidelines, analyzing studies from PubMed, Web of Science, Scopus, and Embase. Eligible studies included observational and genetic investigations on IBD and thyroid disorders. Data extraction and quality assessment were performed using the Newcastle-Ottawa Scale (NOS) and Cochrane Risk of Bias tools. Thirteen studies were included, revealing significant associations between IBD and thyroid disorders. Increased thyroid cancer risk in UC (SIR=10.34) and CD (SIR=10.45) patients. Reduced hypothyroidism prevalence in UC (OR=0.33) in some cohorts. Shared genetic pathways (e.g., IP-10 cytokine mediation) between IBD and autoimmune thyroid disease. Geographic and demographic variations, with higher malignancy risks in Asian IBD populations. IBD is associated with an elevated risk of thyroid disorders, particularly thyroid cancer, though hypothyroidism risk may vary by IBD subtype and population. Immune-mediated mechanisms, including cytokine dysregulation, likely contribute to these associations. Clinicians should consider thyroid screening in high-risk IBD patients, especially those with long-standing disease or specific demographic risk factors. Further research is needed to clarify causal pathways and the impact of IBD treatments on thyroid function.