OPG is associated with thyroid nodule development in type 2 diabetes

Background Thyroid nodule prevalence is increasing lately, especially in diabetes, but the mechanism of which is not clear. In this study, we investigated if osteoprotegerin (OPG) is involved in the pathogenesis of thyroid nodules in diabetes. Methods A total of 7568 individuals with detailed information and ultrasound examination results were studied for the prevalence of thyroid nodules. Among them, 1883 were with type 2 diabetes and 5685 were non-diabetic. Then, 1120 individuals were randomly selected for the measurement of OPG. Diabetic rats were made by feeding a high-fat-high-fructose diet for 28 weeks. Rats fed with a normal diet were as controls. Fresh thyroid tissues were obtained and fixed, dehydrated, and embedded in paraffin for hematoxylin-eosin staining and observing pathological changes. qPCR and western blot were used to detect OPG expression in rat thyroid tissues. Results We found that HbA1c is an independent risk factor for thyroid nodules (Exp [beta] = 1.158, p < 0.001). The prevalence of thyroid nodules in type 2 diabetes was higher than that in non-diabetes (53.9% vs. 46.7%, p < 0.001). Serum OPG levels were significantly elevated in the diabetes group than in the non-diabetes group (3160.17 pg/ml vs. 2819.39 pg/ml, p < 0.01). The expression of OPG increased significantly in the thyroid tissues of diabetic rats. Conclusion Osteoprotegerin may be associated with thyroid nodule development in diabetes.