Investigation of the Global Trend of Thyroid Cancer Incidence and Its Relationship with the Prevalence of Type 2 Diabetes: An Application of Longitudinal Random Effects Regression Model

Background: In recent years, the incidence of thyroid cancer has been increasing. On the other hand, those with insulin resistance often have higher thyroid volume and a risk of developing thyroid nodules. Objectives: The objective of this study was to investigate the global trend of thyroid cancer and its relationship with the prevalence of type 2 diabetes. Methods: The information in the present study is related to the prevalence of type 2 diabetes and the incidence of thyroid cancer in all countries of the world, which was extracted from the Global Burden of Disease site during 1990 - 2019. In order to investigate the relationship between the prevalence of type 2 diabetes and the incidence of thyroid cancer, a longitudinal random effects regression model was used with both random effects of intercept and the slope of the regression line. Results: The results showed that the risk of developing thyroid cancer associated with diabetes was 0.00024 (95% CI 0.00023 - 0.00025), 24 persons per 100000. This significance level was also evaluated separately in men and women, so that the relative risk in men was estimated to be 0.00018 (95% CI 0.00017 - 0.00019) and in women equal to 0.00033 (95% CI 0.00031 - 0.00035). Conclusions: Findings showed that type 2 diabetes can be a risk factor for thyroid cancer. So that this effect can be considered on both men and women and is more intense in women than men.