Abstract
In a cross-sectional analysis of 14,973 adults from North China, thyroid nodules (TNs) were detected via high-resolution ultrasonography in 8,104 participants (54.1%), with a higher prevalence among women. The mean age of those with TNs was significantly higher (51.39 ± 15.41 vs 41.83 ± 12.43 years, p < 0.001). Univariate analyses indicated that female sex (OR ≈ 2.0), older age (OR ≈ 1.03 per year), elevated low-density lipoprotein cholesterol, low high-density lipoprotein cholesterol, and higher BMI were significantly linked to TNs. In contrast, total cholesterol and uric acid did not reach significance in the final model. A nomogram incorporating these risk factors demonstrated moderate predictive performance (AUC = 0.84 in the training set; 0.78 in the validation set). While the study's large sample size is a strength, its cross-sectional design limits conclusions about causality, and potential overfitting cannot be excluded. Future research should include thyroid hormone measurements, external validation of the nomogram, and longitudinal follow-up to clarify the role of metabolic factors. These findings highlight the importance of age, sex, and metabolic profiles - particularly dyslipidemia and obesity - in screening for TNs during routine health examinations.