Objective  To investigate the relationship between uric acid and the incidence of thyroid nodules (TNs) in health examinees in Anhui province for early intervention on TNs incidence.

  Methods  Totally 3 151 adults having regular health examinations at the Health Management Center of the First Affiliated Hospital of Anhui Medical University during January 2017 – September 2021 were recruited for a retrospective follow-up study and the enrollees had no TNs and other thyroid diseases and renal insufficiency but had complete information on laboratory detections at the enrollment. The incidence of TNs among the participants was observed until September 30, 2021. The relationship between uric acid and TNs incidence was analyzed using univariate and multivariate Cox proportional hazards regression models.

  Results  All participants completed the study, with a total follow-up of 7 251.03 person-years and an average follow-up of 2.30 ± 0.84 person-years. During the follow-up period, 605 incidents of TNs were observed and the TNs incidence density was 83.44/1 000 person-years and the cumulative incidence rate of TNs was 19.20%. Among the participants with low, normal, and high uric acid, the observed number of TNs incidence were 184, 277, and 144, with incidence densities (1/1 000 person-years) of 102.57, 75.34, and 80.88, respectively. The results of the univariate Cox proportional hazards regression model analysis showed that the participants with low uric acid were at an increased risk (hazard risk HR = 1.352, 95% confidence interval 95% CI: 1.122 – 1.629) of TNs incidence compared to the participants with normal uric acid. After adjusting for gender, age, serum creatinine, blood urea nitrogen, glomerular filtration rate, serum alanine aminotransferase, serum triiodothyronine, and the presence of hypertension, hyperglycemia, hypertriglyceridemia, and low high-density lipoprotein cholesterol, the risk of TNs increased (HR = 1.278, 95%CI: 1.029 – 1.585) in the participants with high uric acid compared to that in the participants with normal uric acid. Subgroup analysis results revealed that the participants with both higher uric acid and following characteristics had an increased risk of TNs incidence: being female (HR = 1.886, 95%CI: 1.080 – 3.294), aged ≥ 60 years (HR = 1.461, 95%CI: 1.021 – 2.091), suffering from hypertension (HR = 1.604, 95%CI: 1.150 – 2.238), with hypertriglyceridemia (HR = 1.761, 95%CI: 1.010 – 3.072), and having low high-density lipoprotein cholesterol (HR = 1.530, 95%CI: 1.075 – 2.179) in comparison with the participants with those characteristics but normal uric acid.

  Conclusion  High uric acid is associated with the increased risk of TNs among health examinees in Anhui province and the increased risk is much higher in the high uric acid sufferers being female, aged ≥ 60 years, with hypertension, hypertriglyceridemia, or low high-density lipoprotein cholesterol.