The Association between the Thyroid Feedback Quantile-based Index and Serum Uric Acid in U.S. Adults

Abstract

Abstract OBJECTIVE Previous studies have shown that there may be a positive correlation between serum uric acid level and hyperthyroidism. However, the relationship between thyroid function and serum uric acid in healthy people is not clear. The purpose of this study was to analyze the relationship between sensitivity to thyroid hormones and serum uric acid levels, and to present them in quantitative form. RESEARCH DESIGN AND METHODS This study is a cross-sectional study of 4,600 adults (male: 2,366; female: 2,234) who participated in the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2010. Parameters representing central sensitivity to thyroid hormones were calculated as: Thyroid Feedback Quantile-based Index (TFQIFT4), TSH index (TSHI), and thyrotropin T4 resistance index (TT4RI); Peripheral sensitivity to thyroid hormone was evaluated by FT3/FT4 ratio. In addition, we have innovated TT3RI and TFQIFT3 indices based on FT3 and TSH. The relationship between thyroid hormone sensitivity and serum uric acid concentration was analyzed by multiple linear regression. RESULTS Higher levels of serum uric acid were associated with decreased sensitivity to thyroid hormones in euthyroid individuals. Further analysis revealed that TFQIFT4, TFQIFT3, TT4RI, TT3RI, TSHI had a significant correlation with serum uric acid levels in women and obese people; in people aged 20-39, except for TFQIFT4, other thyroid sensitivity indexes were positively correlated with serum uric acid levels. CONCLUSIONS Decreased sensitivity to thyroid hormones was associated with high levels of serum uric acid in people with normal thyroid function, and subgroup analyses showed similar results. It is possible to use the findings of this study to gain a better understanding of the effects of decreased thyroid hormone sensitivity on uric acid metabolism, and to provide clinical diagnosis and treatment references.