Frequency of Nodular Goiter in Patients with Non-Functional Adrenal Incidentaloma

ABSTRACT

Objective: Thyroid nodules and metabolic disorders such as obesity, insulin resistance (IR), and dyslipidemia are frequently reported in patients with non-functional adrenal incidentaloma (NFAI). This study aimed to evaluate the structural and functional properties of the thyroid gland and to elucidate whether there is any relationship between these and metabolic parameters in patients with NFAI. Material and Methods: Fifty-four patients diagnosed with NFAI and 54 age, gender, and body mass index (BMI) matched healthy controls were included in the study. Free thyroxine (fT4), thyroid-stimulating hormone (TSH), anti-thyroperoxidase antibody (anti-TPO), fasting blood glucose (FBG), fasting insulin level, lipid profiles, C-reactive protein (CRP) levels were estimated in the patients and controls. Furthermore, patients and controls were evaluated by ultrasonography to determine thyroid structure, thyroid volume, and thyroid nodules. Results: The mean total thyroid volume of the NFAI group (13.48±6.3 mL) was significantly higher as compared to that of the control group (13.13±10 mL) (p<0.001). Thyroid nodules were detected in 18 (33.3%) of 54 subjects in the NFAI group and 16 (29.6%) of 54 subjects in the control group, resulting in an insignificant difference (p = 0.836). However, the average number of thyroid nodules was significantly higher in the NFAI group (1.72) compared to the control group (1.06) (p<0.001). The thyroid nodule size of the NFAI group (17.83±9.01 mm) was also significantly larger than the control group (11.68±4.68 mm) (p=0.017). Moreover, a significant association between the thyroid nodule and TSH (p=0.026) and between thyroid nodule size and adenoma size (p=0.046) in the NFAI group was pronounced. Conclusion: In our study, we found that certain parameters related to the thyroid gland, such as thyroid volumes, average number of thyroid nodules, and thyroid nodule sizes, were significantly higher in NFAI patients than in healthy controls. There was no significant difference in terms of thyroid functions and thyroid nodule frequency. In this regard, studies with larger sample size, encompassing all factors that may affect thyroid structure and functions, are essential.