Thyroid nodules as predictors of adenomatous colonic polyps: A systematic review and meta-analysis

Thyroid nodules (TN) are increasingly diagnosed worldwide; investigating the association between TN and colon polyps could be helpful in early detection and management. To our knowledge no meta-analysis has assessed the relationship between TN and adenomatous colonic polyps.

To assess the association between adenomatous colonic polyps, thyroid-stimulating hormone, and TN.

We searched PubMed, MEDLINE, Cochrane Library, EBSCO, and the first 100 articles in Google for articles published in English from inception until April 2025. We included prospective cohorts, retrospective studies, case-control studies, and cross-sectional studies. The keywords thyroid nodules, adenomatous colon polyps, thyroid volume, metabolic syndrome, insulin resistance, and thyroid malignancy were used.

Out of 237 articles, 25 full texts were reviewed, and 5 full texts were included in the final meta-analysis. No relationship was found between TN, colonic polyps, and thyroid-stimulating hormone levels [odd ratio (OR): 1.78, 95% confidence interval (CI): 0.55-5.74, P = 0.33]. Colonic polyps were more common among patients with TN when addressing heterogeneity (OR: 0.42, 95%CI: 0.30-0.52, P < 0.001 and OR: 0.08, 95%CI: 0.70-0.86, P = 0.85).

TN were similar among patients with and without adenomatous colonic polyps. However, TN was more common among colon polyps when addressing the heterogeneity. Thyroid-stimulating hormone was not different between those with and without TN. Age, sex, adiposity, and smoking effects might explain the higher rate observed by the included studies. Further studies controlling for the same are needed.