The Association Between Thyroid Volume and Insulin Resistance in Patients with Non-Functional Adrenal Incidentaloma

ABSTRACT

Objective: This study aimed to investigate the association between insulin resistance (IR) and thyroid volume (TV) along with thyroid nodule in patients with nonfunctional adrenal incidentaloma (NFAI). Material and Methods: Fortyfive NFAI patients with a mean age of 59.00±7.00 and 43 healthy controls of comparable age and body mass index (BMI) were included. Sociodemographic data, fasting plasma glucose (FPG), alanine aminotransferase (ALT), insulin, lipid, and hormonal parameters, TV, nodule frequency, and adrenal mass dimensions were retrospectively recorded in all the patients. Resuls: Triglyceride (TG), insulin, HOMA-IR, basal cortisol, and cortisol levels after dexamethasone suppression test (DST) were significantly higher in the patient group (p<0.05). Although the frequency of thyroid nodules was higher in the patient group than in the control group, this finding was statistically insignificant (64.4% and 53.5%, respectively, p=0.296). TV was significantly higher in the NFAI group (13.30±5.95 and 5.99±3.04, respectively p<0.001). After grouping the participants according to insulin resistance; BMI, FPG, triglyceride, and fasting insulin levels were significantly higher in the IR group (p<0.05). Though the frequency of thyroid nodules was higher in those with IR, it was not statistically significant (62.2% and 56.9%, p=0.617).TV was significantly higher in participants with IR (11.23±7.15cm) compared to those without IR (8.64±4.77) (p=0.045). Conclusion: Increased insulin resistance was observed in patients with NFAI. It may play a role in increasing the TV and nodule formation, besides subclinical cortisol secretion.