Prevalence Of Thyroid Nodules In Healthy Population

[Objective] To evaluate the prevalence and characteristics of thyroid nodules as well as the relationship between nodules and serum thyroid-stimulating hormone (TSH) in healthy population.[Methods] A total of4687adults without a history of thyroid disease were included in the retrospective study. And the population data was from the health-care center of Shandong Provincial hospital between2004and2008. The incidence of thyroid nodules as well as its relationship with age, gender and serum TSH were estimated.[Results](1) A total of4687subjects were involved in the study, including2759men and1928women. Thyroid nodules were found in1412subjects. That was, the prevalence of thyroid nodules was30.12%in the studied population. Thyroid nodules were more prevalent in female than in male (34.12%VS27.13%), and the difference was statistically significant (x2=27.35, P<0.01)(2) Subjects were grouped according to their age and gender, and then incidence of thyroid nodules was evaluated in each subgroup. The incidence of thyroid nodules increased with age increasing both in males and females, and Cochran-Armitage trend test showed a liner trend between age and incidence of nodules in the whole population (P<0.01).Thyroid nodules were more popular in females. The prevalence of thyroid nodules in females aged40～and60～was significantly higher than that in males of the same age group (P<0.05).(3) In subjects with thyroid nodules, solitary nodule accounted for65.44%(924/1412). And the ratio between solitary nodule and multiple ones in different age groups showed a significant difference. Multiple nodules seemed to be more common in the elderly. While no obvious difference was observed in the number of thyroid nodules between men and women (χ2=0.93,P=0.34).(4) The relationship between nodules and serum TSH were conducted in526subjects whose serum TSH was measured. Thyroid nodules were detectable in399subjects and most of them (197out of232men and131out of167women) were euthyroidism (328/399,82.2%). The remained71subjects with nodules,52subjects whose serum TSH were above4.5mU/L while19ones with serum TSH below0.45mU/L.(5) Serum TSH in females with multiple thyroid nodules was significantly lower than those without nodules. No significant difference in serum TSH between groups with and without thyroid nodules both in men and women were found. No evidence showed that the nodule prevalence was relevant with TSH levels.[Conclusions](1) The prevalence of thyroid nodules is high even in healthy population, and it is more popular in the elderly and women.(2) The incidence of thyroid nodules increased with age increasing both in males and females, and a liner trend between age and incidence was found in the whole population (P<0.01).(3) Most nodules were solitary. Multiple nodules were more common in the elderly, but no obvious difference was observed in the number of thyroid nodules between men and women.(4) No significant difference in serum TSH between groups with and without thyroid nodules both in men and women were found. No evidence showed that the nodule prevalence was relevant with TSH levels.