Effect of changes in serum uric acid on the risk of stroke and its subtypes.

ABSTRACT

BACKGROUND AND AIMS: The role of serum uric acid (SUA) in stroke remains controversial and analyses of changes in SUA and stroke are limited. The objective of the study was to investigate the associations of changes in SUA with stroke and its subtypes (ischemic and hemorrhagic stroke). METHODS AND RESULTS: A total of 51 441 participants (mean age 52.69 ± 11.71 years) without history of myocardial infarction or stroke were enrolled. Participants were divided into four groups based on SUA level changes during 2006 and 2010 stable low, increasing, decreasing, and stable high. SUA score was quantified on a 3-point scale with 1 point awarded for hyperuricemia at either year 2006, 2008 or 2010. Multivariate Cox proportion models were used to calculated hazard ratios (HRs) and their 95% confidence intervals (CIs). During 7.03-year follow up, 1611 stroke (1410 ischemic stroke, 199 hemorrhagic stroke, and 47 subarachnoid hemorrhage) were identified. Participants with stable high SUA had higher risk of hemorrhagic stroke, the HR was 1.93 (95% CI 1.06-3.51), compared to those with stable low SUA. Furthermore, cumulative high SUA exposure also increased the risk of hemorrhagic stroke, the HR (95%CI) was 2.99 (1.55-5.74), compared with cumulative low SUA exposure. However, no significant evidence indicated changes in SUA was associated with the risk of total and ischemic stroke, the HRs (95% CIs) were 0.98 (0.74-1.29) and 0.88 (0.65-1.19), respectively. CONCLUSIONS: Stable high SUA was positively associated with the risk of hemorrhagic stroke, but not with total and ischemic stroke risk.