Effect of Age, Gender, and Body Mass Index on Thyroid Bethesda Classification: A Retrospective Study

Abstract

Background: Thyroid cancer incidence is increasing nowadays. Bethesda system classifies fine needle aspiration (FNA) cytology into six categories linked to cancer risk. Several papers have studied relationships between thyroid pathology results and age, gender, and body mass index (BMI), but very few have taken into consideration the Bethesda score. The aim of this study was to assess the relationship between the Bethesda system and age, gender, and BMI. Methods: All the patients who underwent an ultrasound-guided FNA of a thyroid nodule between November 2017 and September 2020 were included in this study (668 subjects, 80.7% women, mean age 50.1 ± 13.3 years). Bethesda classification results, age, gender, and BMI were collected from the archives of the institution’s Pathology Department. Results: The observed proportions of the incremental Bethesda classes (1 through 6) were respectively 13.3%, 57.0%, 15.7%, 6.1%, 4.9%, and 2.8%. Bethesda score was negatively correlated with age (Spearman’s rho = -0.106 (95% confidence interval (CI): -0.180; -0.026), P value = 0.006). The ratio men/women increased with increasing Bethesda score (linear trend P value = 0.043). Bethesda score was not correlated with BMI (Spearman’s rho = 0.049 (95% CI: -0.033; 0.120), P value = 0.21), even after adjustment for gender and age. Conclusions: Bethesda scores decreases with age and are not associated with gender; however, men/women ratio increases with increasing scores. BMI does not correlate with higher Bethesda scores. More studies should be performed to identify factors that might influence Bethesda score. J Endocrinol Metab. 2022;12(3):97-101 doi: https://doi.org/10.14740/jem806