Abstract: Objective To explore the association between body mass index(BMI)of the physical examination population and hyperuricemia(HUA). Methods A retrospective selection was made of 1,305 physical examinees who underwent physical examinations at the physical examination center of a tertiary hospital in Gansu Province from January to December 2023 with complete important variables as the research subjects. Their demographic data and related biochemical indicators were collected. They were divided into the normal BMI group(BMI < 24)(n=569)and the high BMI group(BMI≥24)(n=736). The propensity score matching(PSM)method was used to conduct a 1∶1 match between the two groups to balance the potential confounding factors. The association between BMI and HUA was analyzed through univariate and multivariate logistic regression. The dose-response relationship between the two was analyzed using restricted cubic splines(RCS), and further stratified analysis was conducted for each subgroup of BMI. Results After controlling the covariates between groups by PSM, 343 pairs were successfully matched, and the balance of covariates in both groups was good(SMD <0.1). The differences in the prevalence of HUA between the high BMI group and the normal BMI group before and after matching were statistically significant(30.3% vs. 10.7%, χ2=72.245, P<0.001; 20.1% vs. 14.3%, χ2=4.094, P=0.043). Multivariate logistic regression after PSM showed that the risk of HUA in the high BMI group was 1.781 times larger than that of the normal BMI group(95%CI: 1.078-2.736, P=0.023). RCS analysis indicated that BMI was positively correlated with the risk of HUA. The higher the BMI, the higher the risk of HUA. There was no significant nonlinear association between the two indicators(nonlinear P=0.725). The results of stratified analysis showed that BMI≥26 significantly increased the risk of HUA, especially among men, those aged ≤50 years, and those without chronic diseases(P<0.05). Conclusion High BMI is an independent risk factor for HUA, and the association is more significant in specific populations. PSM effectively controls confounding bias. Paying attention to BMI levels in the physical examination population is of great significance for the prevention and control of HUA. It is recommended to reduce the risk of HUA through body mass management, thereby reducing the burden of metabolic diseases and improving the health level of the population.

Key words: Body mass index, Hyperuricemia, Propensity score matching, Restricted cubic spline