By analyzing the prevalence and influencing factors of thyroid nodules (TN) among a population undergoing physical examinations in Nantong region, this study aims to provide theoretical basis for early prevention and intervention of TN.

A cross-sectional study was conducted, including 6 950 participants who underwent physical examinations at the Affiliated Hospital of Nantong University from January 2017 to April 2020. All participants underwent high-resolution ultrasound examination of the thyroid, and measurements of height, body mass index (BMI), blood pressure. Fasting blood glucose (FBG), total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C), uric acid (UA), homocysteine (HCY) and other metabolic indicators were detected. Data analysis was performed using SPSS 26.0 statistical software. The numerical variables with normal distribution were expressed as mean±standard deviation (x¯±s), and the t-test was used for comparison between the two groups. Numerical variables with non-normal distribution were expressed as median (interquartile range), namely M (Q₁, Q₃). The Mann-Whitney U test was used for comparison between two groups, and the Kruskal-Wallis test was used for comparison between multiple groups.

The prevalence of thyroid nodules among the 6 950 participants was 53.97% (3 751/6 950), with a rate of 47.08% (2 218/4 711) in males and 68.47% (1 533/2 239) in females, which was significantly higher in females than in males (χ²=278.575, P<0.001). The prevalence of TN increased with age both overall (χ²=552.145, P<0.001), in males (χ²=304.086, P<0.001), and in females (χ²=202.178, P<0.001). The prevalence of TN was higher in females than in males across different age groups (P<0.05). In the comparison between males in the TN and non-TN groups, significant differences were found in terms of alcohol consumption history, BMI, blood pressure, HCY, and FBG (all P<0.05). In the comparison between females in the TN and non-TN groups, significant differences were found in terms of BMI, blood pressure, HCY, FBG, TC, TG, LDL-C, and UA (all P<0.05). Univariate logistic regression model showed that FBG<6.1 mmol/L (P<0.001) and TC<5.2 mmol/L (P=0.013) were protective factors for TN. Normal UA (P=0.013) was a risk factor for TN. After adjusting for gender, smoking, alcohol consumption, BMI, and blood pressure, multivariate logistic regression analysis revealed that FBG<6.1 mmol/L (OR: 0.713, 95%CI: 0.621-0.817, P<0.001) was a protective factor against TN.

The prevalence of TN is relatively high in the Nantong region. Gender, age, blood pressure, BMI, and FBG are important influencing factors for TN. Health screening and management should be strengthened for the physical examination population with abnormal indicators.

Thyroid nodules; Prevalence; Risk factors; Physical examination