OBJECTIVE: Previous studies have found that the relationship between metabolic indicators and Hashimoto's thyroiditis (HT) in non-diabetic adults remains unclear. This study aims to explore the association between metabolic indicators and HT, providing new theoretical insights for the clinical management of HT. METHODS: Clinical data were collected from 2,015 non-diabetic adults at Guangdong Provincial Hospital of Chinese Medicine. The relationship between metabolic indicators and HT was analyzed using SPSS 26.0, R (version 4.2.1), and Zstats. RESULTS: Among the 2,015 non-diabetic adult participants included in the study, 1,877 were in the non-HT group, while 138 were in the HT group. Significant differences were observed in metabolic indicators, including serum uric acid (SUA), serum creatinine (SCr), albumin (ALB) and high-density lipoprotein cholesterol (HDL-C), between the two groups, with statistical significance. A binary logistic regression model was established, revealing that SCr had a significant impact in both univariate and multivariate analyses. To further investigate the relationship between metabolic indicators and HT, we conducted a restricted cubic spline (RCS) analysis. The results demonstrated a clear non-linear relationship between SUA and HT, both before and after adjustment (All P <
0.01). Therefore, based on the inflection points derived from the RCS analysis, a segmented logistic regression analysis was performed. The findings indicated a significant association between both low and high levels of SUA and HT (Lower OR: 2.043
95% CI: 1.405-3.019
P <
0.001
Higher OR: 2.369
95% CI: 0.998-4.999
P = 0.034). CONCLUSION: This study is the first to reveal a U-shaped association between SUA levels and the risk of HT, suggesting that maintaining SUA levels within the range of 359.0-540.0 μmol/L may help reduce the risk of HT occurrence. This finding provides a new perspective for early intervention and long-term management of HT, particularly in terms of SUA regulation in HT patients, which holds potential clinical value.