Gender-Specific Associations Between Metabolic Disorders and Thyroid Nodules: A Cross-Sectional Population-Based Study from China.

Background: Metabolic disorders (MDs) and the metabolic syndrome (MetS) may be associated with thyroid diseases. The aim of this study was to investigate the relationship between MDs and various types of thyroid nodules (TNs), according to gender. Methods: We analyzed cross-sectional data from the Thyroid Disorders, Iodine Status, and Diabetes Epidemiological (TIDE) survey in China. A total of 56,729 subjects ≥18 years of age were included. Thyroid gland morphology was assessed by thyroid standardized ultrasonography. A multivariate logistic regression model was used to explore the odds ratio (OR) and confidence intervals [CIs] for any associations between MDs and TNs. Subgroup analyses were conducted according to gender and TN type (solitary, S-TN; multiple, M-TNs). Results: The prevalence of TNs was increased in several MDs, and was higher in women than men regardless of whether they suffered from MDs (22.0%, CI [21.6-22.5%] vs. 15.7%, CI [15.3-16.7%], p  < 0.001). TNs were associated with the presence of MDs (OR = 1.189, CI [1.107-1.278], p  < 0.001), hypercholesterolemia (OR = 1.235, CI [1.177-1.296], p  < 0.001), high low-density lipoprotein cholesterol (LDL-C; OR = 1.249, CI [1.186-1.316], p  < 0.001), and hyperuricemia (OR = 1.206, CI [1.126-1.293], p  < 0.001). MDs and MetS were, respectively, significantly associated with TNs, S-TNs, and M-TNs in men, while MDs were significantly associated with the three TN profiles in women. With respect to dyslipidemia, hypercholesterolemia and high LDL-C had the strongest association with TNs, whereas hypertriglyceridemia had no effect. Conclusions: TNs (especially M-TNs) may be associated with MDs and their various components, and there appear to be some gender-specific associations.