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

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.

The objective of this study was to investigate the global trend of thyroid cancer and its relationship with the prevalence of type 2 diabetes.

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.

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).

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.