Thyroid nodular diseases in the population indergoing medical examination and the analysis of its relative factors in Dalian City,Liaoning Province / 中国地方病学杂志

ABSTRACT

Objective To investigate the characteristics about the prevalence of thyroid nodules detected on color Doppler uhrasonography(US) in people residing in Dalian City who undergo regular physical examinations, as well as its relative factors. Methods All thyroid sonographic and questionair procedures were performed in the 6020 people above 18-year-old living in the four districts of Dalian City for at least 5 years, who were examined at the department of health medical center of Dalian Municipal Central Hospital from May 2006 to March 2007. Urinary iodine concentration was measured in 2039 healthy adults selected by age layers in our study population. Moreover, urinary iodine concentrations were determined in 220 children aged 8-10 years old who were randomly chosen from four communities (55 children per elementary school from each community). The analysis of logistic regression was conducted for the risk factors linked to thyroid nodules. Results The prevalence of thyroid nodules in the 6020 adults was 38.5%(2319/6020), in which nodules sized between 0.3 and up to 0.5 cm were found in 17.1% (1030/6020), and those above 0.5 cm in 21.4% (1289/6020). Ultrsonography revealed solitary nodules in 17.2% (1036/6020), multinodular goiter in 21.3% (1283/6020). Fifty-four point nine percent (1272/2319) thyroid nodules showed solid internal echographic structures, 30.2%(701/2319) mixed and 14.9%(346/2319). The thyroid nodule detected rate in female individuals was 46.1% (1102/2393), among whom multinodular goiter [59.1% (651/1102)] was more than solitary nodules[40.9(451/1102)] in female; while only 33.6%(1217/3627) of male were detected to have thyroid nodule, there was a difference between the genders (χ2=95,079,P<0.01). The mediam urinary iodine concentration(MUI) was 184.32 μg/L in children and 216.75 μg/L in the health adults, moreover, it was 216.55 μg/L and 217.00 μg/L in the people with thyroid nodules and those without nodules without a significant difference (P>0.05). The rate of thyroid nodules gradually increased with age(χ2=344.998, P<0.01). The occurance of thyroid nodules was significant associated with gender and age(P<0.01). Conclusions The nutritional iodine intake in the four communities of Dalian City are adequate. The prevalence of thyroid incidentalomas is relatively high in this group of people receiving medical examination.