Objective: Type 1 diabetes mellitus (T1DM) is associated with an increased risk of thyroid disorders. Identifying predictors of thyroid nodules in these patients may enable more appropriate management strategies. To the best of our knowledge, the relationship between thyroid nodules and inflammatory parameters is not fully investigated in patients with T1DM. The present study aimed to investigate the diagnostic value of several hematological inflammatory indices, such as systemic immune inflammation index (SII) in predicting the presence of thyroid nodules in patients with T1DM.

Materials and Methods: A total of 69 T1DM patients with thyroid nodules and 111 T1DM patients without were included. In patients with T1DM, logistic regression models were performed to assess the independent predictors for thyroid nodules. Receiver operating characteristics (ROC) curve analysis was performed to evaluate the diagnostic accuracy of SII in identifying T1DM patients with thyroid nodules.

Results: Patients with thyroid nodules had higher mean SII values than those without (p<0.001). There was no significant association between age, gender, disease duration, thyroid function tests, and thyroid nodules. The mean SII value was an independent predictor of thyroid nodules in univariate and multivariate logistic regression analyses (p<0.001).

Conclussion: Our findings suggest that inflammation may play an important role in the development of thyroid nodules in patients with T1DM and that SII value may be useful in determining the risk of thyroid nodules in these patients.