Increased Prevalence of Insulin Resistance in Patients With Differentiated Thyroid Carcinoma

Background: Patients with insulin resistance (IR) have a higher prevalence of thyroid nodules. In the present study, we present original data showing that patients with differentiated thyroid carcinoma (DTC) also have a higher frequency of IR. Methods: Twenty women with DTC ( group 1, G1) and 20 euthyroid individuals ( control group, CG) were investigated for IR. G1 and CG subjects were matched in pairs by age, gender, and body mass index (BMI). The diagnosis of IR was made when the homeostasis model assesment of insulin resistance (HOMA-IR) index was higher than 2.5. According to the BMI, 20 women ( 10 with DTC and 10 of the CG) had a BMI < 25, whereas the other 20 had higher BMI values ( overweight and obese patients). Results: IR was present in the 50% of G1, but only in the 10% of the CG ( P < 0.001). In the groups with lower BMI (< 25), we found IR in 30% of G1 and no cases in the CG, whereas in those with BMI > 25 the IR was present in 70% of G1 and 20% of CG. There were no differences between the two subgroups regarding the time in which the IR tests were performed. IR was present in 56.3% of patient with papillary anol 25% of follicular thyroid carcinomas, respectively. Conclusions: We conclude that such a high prevalence of IR would be an important risk factor for developing DTC, as it is well known with some other nonthyroid carcinomas.