Increased Prevalence of Thyroid Nodules Across Nearly 10 Years in Shanghai, China.

Objective: This study aimed to determine whether the prevalence of thyroid nodules (TNs) increased due to modern lifestyles or other factors, despite the advances in screening and diagnostic tools.

Methods: This study included 3474 pairs of participants, who were matched by gender and age (±3 years) from two cross-sectional sampling surveys: (1) the program on the iodine nutritional status and related health status of residents in Shanghai in 2009; (2) the thyroid disease screening program for adults in Shanghai between 2017 and 2018. The prevalence of TNs and thyroid diseases in 2009 and 2017-2018 were compared, and the potential risk factors of TNs were detected.

Results: The prevalence of TNs in 2009 was 28.9%: 22.5% in males and 34.5% in females. In 2017, this increased to 43.8%: 37.9% in males and 49.1% in females. The prevalence of TNs significantly increased from 2009 to 2017 (odds ratio, 1.486; 95% confidence interval, 1.238-1.786). In addition, female gender, thyroid disease history, and age were the main risk factors for TNs after adjusting for confounders in the logistic regression across the time period.

Conclusion: The prevalence of TNs significantly increased across nearly 10 years in Shanghai.