Role of Obesity and Diabetes in the formation of Thyroid Nodules - Analysis of Data from Bulgarian Population Screening in 2024

Thyroid nodules (TN), obesity and diabetes affect millions of people individually and in combination, which suggests the existence of pathogenetic link between them. <i>Aim:</i> To establish the current prevalence of TN in the country and its connection with some of the risk factors causing the disease - gender, age, obesity and diabetes. <i>Material and methods</i>: 936 subjects were divided into three age groups: 20-44 years - 342 (36.5%), 45-59 years - 301 (32.2%) and 60-79 years - 293 (31.3%); Body Mass Index (BMI) was calculated and normal, overweight, and obese groups were formed; TSH (ECLIA-sandwich method), FT4 (competitive ECLIA method) were tested; oGTT was performed to determine plasma glucose at 0 and 120 minutes; Ultrasound examination was applied.<i> Results</i>: Thyroid nodules were detected in 40.85% (382/935) of the subjects, with higher prevalence in women compared to men - 46.4% (222/478) vs. 35.0% (160/457), p < 0.05. The prevalence of TN increased with age: 60-79 years vs. 20-44 years - more significantly in the overall group (54.3%, 159/293 vs. 29.2%, 100/342, p < 0.001) and in women (59.9%, 103/172 vs. 30.2%, 48/259, p < 0.001), but less in men (46.3%, 56/121 vs. 28.4%, 52/183, NS). Out of the 382 individuals with TN, only 27.5% (105/382) had normal weight (BMI < 25 kg/m²), while 72.5% (277/382) were overweight or obese (BMI ≥ 25 kg/m²), p < 0.001. Among diabetics (n=155), 46.5% (72/155) had both type 2 diabetes (T2D) and TN. It was established that 38.1% (59/155) of them had BMI ≥ 25 kg / m², whereas only 8.4% (13/155) were with normal weight (BMI < 25 kg/m²), p < 0.02. In the group of patients with TN (n-382), 18.8% (72/382) had a combination of TN and T2D, with 15.4% (59/382) having a BMI ≥ 25 kg/m<i>2</i> and only 3.4% (13/382) having normal weight (BMI < 25 kg/m<i>2</i>), NS. Among the individuals with BMI ≥ 25 kg/m² (n=637), TN was present in 43.5% (277/637), of whom 21.3% (59/277) had T2D as well. Thus, approximately one in five individuals with BMI ≥ 25 kg/m² and TN, also had T2D. <i>Conclusion:</i> The current data clearly demonstrate very strong connection between obesity, T2D and TN. When any of these conditions are present, we should be look for the other two in order to ensure early diagnosis and appropriate therapeutic intervention.