Association Between Uric Acid and Hemorrhagic Transformation: A Systematic Review and Meta-Analysis

BackgroundThe relationship between uric acid (UA) and hemorrhagic transformation (HT) remained controversial. The purpose of this study was to investigate the relationship between UA degrees and the risk of HT after acute ischemic stroke (AIS). Methods and methodsElectronic databases were sought for studies on UA and HT from inception to October 31, 2023. Two researchers independently reviewed the studies for inclusion. STATA Software 16.0 was used to compute the standardized mean difference (SMD) and 95% confidence interval (CI) of the pooled and post-outlier outcomes. The heterogeneity was evaluated using the I2 statistic and the Galbraith plot, and sensitivity analysis was also performed. Beggs funnel plot and Eggers test were used to assess publication bias. Results12 trials were included in the meta-analysis, with a total of 4,708 individuals. Low UA degrees were linked to higher HT post-AIS patients following the pooled SMDs forest plot (SMD = -0.34, 95% CI = -0.60-0.08, P = 0.010). The high heterogeneity (I2 = 89.0%, P<0.001) was found in the studies. Six papers were outside the Galbraith plot regression line and there was no heterogeneity when they were excluded (I2 = 45.8%, P = 0.100). Meanwhile, the repeated SMDs (SMD = -0.487, 95% CI = -0.632-0.342, P = 0.000) still meant that the HT group had lower UA degrees. There was no publication bias in our meta-analysis following Beggs funnel plot or Eggers test. ConclusionsThe meta-analysis illustrated a substantial positive connection between UA degrees and HT, with lower UA separately linked with higher HT post-AIS. It provided a certain theoretical basis for the later related research.