To observe the changes of serum uric acid and serum 25(OH)D3 levels in middle school students, and to explore their relationship.

A total of 217 middle school students in Shijingshan District, Beijing were selected to measure their serum uric acid levels by uricase peroxidase method, and their serum 25(OH)D3 levels by electrochemiluminescence method. Meanwhile, blood pressure, height, waist circumference, and weight were measured, and body mass index was calculated. Furthermore, subgroup analysis by gender was carried out. The measurement data between the two groups were compared by two independent samples t test. The relationship of the levels of serum uric acid in boys with serum 25(OH)D3 was analyzed by Pearson correlation. Multivariate binary logistic regression analysis was performed to evaluate the association of serum 25(OH)D3 level, eating habits, exercise, sleep, etc. with the prevalence of hyperuricacidemia in boys. For each unit increase in 25(OH)D3, the odds ratio (OR) of the prevalence of hyperuricemia and its 95% confidence interval (CI) were calculated.

Among the 217 students included, the proportion of students with high uric acid was 37.33% (81/217), and their diastolic blood pressure was significantly higher than that of students with normal uric acid (P＜0.05). The 25(OH)D3 level (19.01±6.48) in boys of the high uric acid group was significantly lower than that in the normal uric acid group (21.81±6.31; P=0.041); the serum uric acid levels of boys were negatively correlated with 25(OH)D3 levels (r=-0.22, P=0.032). After adjusting for beverage, sleep, tea, and other factors, 25(OH)D3 was an independent protective factor for high uric acid (OR=0.933, P=0.045).

This cross-sectional study confirmed that blood 25(OH)D3 is inversely correlated with hyperuricemia, and such correlation only exists in boys.