General characteristic of all subjects with and without thyroid nodules (TNs)
| All | TN(−) | TN(+) | p Value | |
| N (%) | 4024 (100) | 2357 (58.6) | 1667 (41.4) | − |
| Age (years)* | 54.15±13.08 | 51.96±13.13 | 57.26±12.35 | <0.001 |
| Smokers (n(%)) | 2098 (52.1) | 1208 (51.3) | 890 (53.3) | 0.135 |
| Metabolic factors | ||||
| BMI (kg/m2)* | 24.86±3.33 | 24.65±3.40 | 25.17±3.22 | <0.001 |
| Waist-to-hip ratio* | 0.89±0.07 | 0.89±0.07 | 0.90±0.08 | <0.001 |
| HOMA-IR | 1.49±2.80 | 1.46±2.94 | 1.54±2.57 | 0.016 |
| HbA1c (%) | 5.62±1.02 | 5.54±0.94 | 5.73±1.11 | <0.001 |
| LDL (mmol/L)* | 3.08±0.76 | 3.05±0.76 | 3.13±0.75 | 0.003 |
| HDL (mmol/L)* | 1.36±0.32 | 1.37±0.32 | 1.33±0.32 | <0.001 |
| TG (mmol/L) | 1.89±1.91 | 1.88±2.02 | 1.90±1.73 | 0.021 |
| TC (mmol/L)* | 5.14±1.04 | 5.13±1.03 | 5.16±1.05 | 0.321 |
| Systolic pressure (mm Hg)* | 134.58±20.81 | 133.43±20.65 | 136.22±20.92 | <0.001 |
| Thyroid hormones | ||||
| TSH (mIU/L) | 2.46±3.20 | 2.44±2.70 | 2.47±3.78 | 0.570 |
| T3 (nmol/L) | 1.79±0.48 | 1.79±0.51 | 1.79±0.44 | 0.647 |
| T4 (nmol/L)* | 113.88±22.72 | 112.95±22.48 | 115.18±23.00 | 0.002 |
| TPOAb (U/ml) | 69.36±204.21 | 65.46±196.92 | 74.86±214.02 | <0.001 |
| TPOAb (+) (n(%)) | 332 (8.3) | 179 (7.6) | 153 (9.2) | 0.073 |
| TgAb (+) (U/ml) | 27.97±61.62 | 26.24±54.47 | 30.41±70.44 | 0.001 |
| TgAb (+) (n(%)) | 232 (5.8) | 131 (5.6) | 101 (6.1) | 0.506 |
Data were summarised as the mean ±SD for continuous variables or as a number with proportion for categorical variables.
*These data were normal distribution.
BMI, body mass index; HbA1c, glycated haemoglobin; HDL, high-density lipoprotein; HOMA-IR, homeostasis model assessment of insulin resistance; LDL, low-density lipoprotein; T3, triiodothyronine; T4, thyroxine; TC, total cholesterol; TG, triglycerides; TgAb, thyroglobulin antibody; TN(+), participants with thyroid nodule(s); TN(−), participants without thyroid nodule; TPOAb, thyroid peroxidase antibody; TSH, thyroid-stimulating hormone; Smokers: smoking history including current and past.