Changes Of Serum Uric Acid Level During The Acute Gout Flare And Related Factors

Objective: By studying the changes of serum uric acid(SUA)in acute stage and remission stage of gouty arthritis,we aimed to explore the relationship between the changes of SUA level and free glucocorticoids and inflammatory factors.Methods: This study is a prospective,single center,longitudinal study.In this study.50 patients with acute gout were selected from the gout clinic of the Affiliated Hospital of Qingdao University from October 2020 to September 2021.All selected subjects asked about their past history and recent medication history in detail.According to the inclusion and exclusion criteria,39 patients were finally included in the study.Blood samples,morning urine samples and 24-hour urine samples were collected at the first visit during the acute phase.Then patients with acute gouty arthritis were mainly treated with colchicine and nonsteroidal anti-inflammatory drugs(NSAIDs)for 1 week.Then stop taking the above drugs after 1 week later.Blood samples,morning urine samples and 24-hour urine samples were collected again 2 weeks after the first visit.The parameter of blood samples during acute and intermission period of gout arthritis were compared,including serum uric acid(SUA),alanine aminotransferase(ALT),aspartate aminotransferase(AST),fasting blood glucose(GLU),triglyceride(TG),total cholesterol(TC),urea nitrogen(BUN),serum creatinine(SCr),C-reactive protein(CRP),interleukin-1β(IL-1 β),Interleukin-6(IL-6),tumor necrosis factor α(TNF-α),serum cortisol(CORT),morning urinary p H,and 24-hour urinary indicators,including 24-hour fractional excretion of uric acid(24h FEur),24-hour urinary uric acid excretion(24h Uur),excretion of uric acid per volume of glomerular filtration(Eur GF),24-hour urinary free cortisol(24h UFC)concentration.The paired t test was used to compare the changes of parameters at two consecutive time points.Pearson’s correlation was applied to assess the relationship.Result: A total of 32 patients completed the 2-week follow up trial.(1)The level of SUA during the acute attack was significantly downregulated than that after attack(464.14 ± 90.97 vs.527.36 ± 86.90 μmol/L,p<0.001).The 24-hour fractional excretion of uric acid(5.54 ±2.82% vs.4.68 ±2.83%,p<0.001)and 24-hour urinary uric acid excretion increased(663.08 ±249.48 μmol/L vs.540.87 ±263.18 μmol/L,p=0.001)in patients during the acute phase signally.(2)The 24-hour urinary free cortisol concentration in the acute phase was significantly higher than that in the intermission period(13.41 ± 14.22 ng/ml vs.8.46 ± 6.07 ng/ml),and there was significant statistical difference(p= 0.039).There was also a slight increase in serum cortisol(394.15 ± 172.49 vs.382.22 ± 147.69)but without statistical difference(p= 0.676).(3)Compared with intermission period,the levels of C-reactive protein(38.12 ± 48.46 vs.7.55 ± 9.82,p= 0.014),interleukin-1β(55.92 ± 45.54 vs.41.86 ± 32.42,p= 0.028)and interleukin 6(45.89 ± 96.51 vs.8.75 ± 6.43,p= 0.031)increased significantly when patients suffered from the acute gout attack,and there was significant statistical difference between the groups.(4)Percent change in SUA was correlated with percent change in 24 h FEur and percent change in C-reactive protein.Meanwhile,the percent change in 24 h Uur was correlated with percent change in 24-hour urinary free cortisol(24h UFC),percent change in interleukin 1β(IL-1β)and percent change in interleukin 6(IL-6).24 h UFC,IL-1β and IL-6 was also elevated during the gout attack.Conclusion: The serum uric acid in gout patients during the acute phase decreased by 63.22 μmol / L,about 12% lower than the after treatment,accompanied by the increase of 24-hour uric acid excretion fraction and 24-hour urinary acid excretion.The decreased SUA level during the acute gouty attack was associated with the increased excretion of urinary uric acid.The 24-hour urinary free cortisol concentration,C-reactive protein,interleukin-1β and interleukin-6 increased significantly in the acute phase.Besides,the changes of 24-hour urinary acid excretion were correlated with 24-hour urinary free cortisol concentration,C-reactive protein,interleukin-1β and interleukin-6.The inflammation indicators and bioactive free glucocorticoids may play an important role.