Fasting serum glucose, thyroid‐stimulating hormone, and thyroid hormones and risk of papillary thyroid cancer: A case‐control study

BACKGROUND: This study was to investigate the association of fasting serum glucose (FSG), thyroid-stimulating hormone (TSH), and thyroid hormones with papillary thyroid cancer (PTC). METHODS: A total of 649 participants were included in this case-control study. The associations of FSG, TSH, free triiodothyronine (FT3) and free thyroxine (FT4) with PTC were estimated using an unconditional logistic regression. RESULTS: Compared with the lowest quintile of TSH levels, odds ratios (ORs) and 95% confidence intervals (CIs) for association between PTC risk and highest quintile of TSH levels were 1.67 (95% CI, 0.99-2.83). However, this risk correlation was more significant in PTC cases with ≤1.0 cm tumor size (adjusted OR, 1.95; 95% CI, 1.08-3.54; adjusted P-trend, 0.05). The PTC risk was also inversely associated with the serum FT3 level in all participants (adjusted P-trend, 0.001), but positively associated with the serum FT4 (adjusted P-trend, 0.001) and FSG (adjusted P-trend, 0.01) levels. Among the participants without diabetes, the individuals with high FSG levels and abnormal TSH concentration had an increased PTC risk (adjusted OR, 3.38; 95% CI, 1.78-6.42). CONCLUSION: The current study provides evidence for the association of FSG, TSH, and thyroid hormones (FT3 and FT4) with PTC risk. However, larger relative studies are needed.