The Relationship between Insulin Resistance and Thyroid Volume in Georgia

Patients with insulin resistance (IR) have a higher thyroid volume therefore the aim of our study is to examine the correlation between IR and thyroid volume in the residents of Georgia.

413 patients with a mean age of 37.3 ± and 11.4 years were included in this study. Out of those, 120 were males, and 293 were females who were studied retrospectively. They had hyperinsulinemia and were referred to the clinic from 2017 to 2019. The factors studied were age, sex, body mass index (BMI), clinical signs, thyroid ultrasound, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipids, fasting insulin, fasting glucose, thyroid stimulating hormone (TSH), Free thyroxine (FT4), and Zinc (Zn).

IR was detected in 252 individuals. The frequency of men with insulin resistance was significantly higher than in the control group - 72.50%, and 56.31%, respectively (F = 9.55, p= 0.0021). Mean thyroid volume in the patients with IR was significantly higher compared to the controls 20.52 + 6.39 cm³ and 15.25 + 6.55 cm³, respectively (p < 0.001). Hyperinsulinemia had a significant positive correlation with Goiter r = 0.445, p < 0.0001. The associated factors for hyperinsulinemia are: Goiter (1) - OR = 5.12 (95% CI:3.02-8.69); Cholesterol - OR = OR = 3.31 (95% CI: 1.54-7.14); Triglycerides - OR = 3.23 (95% CI:1.02-10.28); Obesity (1)- OR = 3.94 (95% CI: 2.23-6.98); Thyroid structural changes (1) - OR = 2.01 (95% CI: 1.12-3.60); ALT/AST-OR = 4.53 (95% CI: 2.33-8.80); Zn decreased Odds Ratio hyperinsulinemia - OR = 0.95 (95% CI: 0.94-0.97).

Hyperinsulinemia is the most common cause of diffuse goiter and the heterogeneous structure of the thyroid. The volume of the thyroid gland shows a significant positive association with the characteristics of metabolic syndrome and increased thyroid volume predictors of metabolic syndrome.