Retrospective analysis of thyroid functions and sonographic characteristics of the thyroid gland in a health check-up population in China during 2020–2024

Abstract

Objectives This study aimed to investigate the epidemiological characteristics and temporal trends of thyroid structural and functional abnormalities among adults undergoing health examinations in Dalian, a coastal city where iodine intake levels raise concerns. Methods This single-center retrospective cross-sectional study included adults who underwent thyroid ultrasonography and function testing at the Health Management Center of the First Affiliated Hospital of Dalian Medical University from January 2020 to December 2024. Prevalence and temporal trends were analyzed according to sex, age, and year. Results The overall prevalence of thyroid ultrasound abnormalities was 74.85%, including nodules (49.29%), cysts (36.91%), heterogeneous echotexture (22.96%), and suspected parathyroid lesions (2.91%). Thyroid function abnormalities were detected in 7.57% of participants, predominantly driven by TSH alterations (86.32% of functional disorders). Thyroid autoantibody positivity reached 33.02%. From 2020 to 2024, structural abnormalities showed a gradual upward trend, whereas thyroid function and antibody abnormalities declined. Females had slightly higher rates of structural abnormalities and markedly higher rates of thyroid function abnormalities (9.05% vs. 5.62%) and antibody positivity (43.87% vs. 19.06%; both p < 0.001). The detection rates of nodules and cysts increased significantly with age, while antibody positivity decreased with advancing age. Conclusion Thyroid abnormalities are highly prevalent in this health check-up population. Routine ultrasonography combined with a TSH-first screening strategy may facilitate early detection and risk stratification while balancing screening burden and cost-effectiveness. Particular attention should also be given to thyroid autoantibody screening, especially among young and middle-aged women.