Prevalence of thyroid nodules in a healthy population.

Objective To assess the incidence and features of thyroid nodules in physical examinations.Methods A total of 4687 adults without a history of thyroid disease were enrolled in the study.Thyroid ultrasonography was performed in all subjects and serum thyrotropin(TSH) was evaluated in 526 of them who were subdivided into two groups according to the presence or absence of thyroid nodules.Serum TSH was compared between these two groups.Results The prevalence of thyroid nodules was 30.12% in the studied population and increased with age.Thyroid nodules were significantly more common in females than males(34.13% vs 27.33%,P0.01).Spearman rank correlation analysis indicated a positive correlation between age and the occurrence of thyroid nodules(P0.01).Multiple nodules were more prominent in elderly people,but no obvious difference was observed in the number of thyroid nodules between men and women.Most nodules were smaller than 1cm(65.79%)and the echo-structure of nodules was solid in 56.94%,mixed in 27.12% and cystic in 15.93% of the cases.There was also no significant difference in serum TSH between groups with and without thyroid nodules(P0.05).Conclusion The prevalence of thyroid nodules is high in healthy adults and increases with age.Most nodules were small,solitary and solid in the studied population.