Is It Appropriate to Adjust the Uric Acid Reference Interval?

BACKGROUND: This study aims to explore the observable distribution of serum uric acid levels in healthy adults residing in China's coastal areas and to assess the suitability of current reference intervals.

METHODS: The study incorporated 20,786 participants. The overall uric acid level displayed a skewed distribution, leading to the division of subjects into six groups based on gender and age. The analysis was conducted to comprehend the distribution of UA in various groups and seasons, establish and validate the reference intervals for the surface healthy population in this region, and analyze the abnormality rates using different reference intervals.

RESULTS: Statistically significant differences were observed between the uric acid levels of males and females across all age groups (ALL p < 0.05). Furthermore, there were statistical differences in uric acid levels among different age groups for both genders (H = 69.593 and 326.348, all p < 0.001). The overall reference interval was determined as 238 - 488 µmol/L for males and 155 - 364 µmol/L for females, based on the 95% confidence interval (P2.5 - P97.5). The established reference intervals, grounded on gender and age group, were validated, showing statistically significant disparities in UA levels among groups. The abnormality rate in males decreased by 56.90% following the adjustment of the reference interval.

CONCLUSIONS: The study revealed that UA levels at all ages exhibited varying degrees of "right shift". Additionally, the low-value population should not be overlooked in the clinical evaluation of UA test results. Setting a reasonable reference interval and clinical decision level is crucial for clinical diagnosis and treatment.