Serum uric acid and risk of ischemic stroke: The ARIC Study

Aims: Since serum uric acid (UA) is strongly associated with cardiovascular risk factors, it has been debated whether serum UA is a stroke risk factor or whether UA may be simply "marking" subjects with other, causal risk factors. We therefore investigated the relation between UA and ischemic stroke in the Atherosclerosis Risk in Communities (ARIC) Study. Methods and results: Of 15,792 ARIC participants, 13,413 who were free of recognized stroke or coronary heart disease (CHD) at baseline and had a baseline UA measurement were included in the analysis. We followed the participants for ischemic stroke incidence (N=381) over 12.6 years. Although serum UA was independently and positively related to ischemic stroke incidence when we adjusted for age, sex, race, and education, the positive relation was weakened when additionally adjusted for possible confounding variables. The positive multivariate-adjusted association between serum UA and ischemic stroke was observed among subjects not using diuretics (adjusted relative hazard in the highest quartile versus the lowest: relative hazard (RH) = 1.49; 95% confidence interval (CI): 1.00-2.23) (P for trend: 0.02), but not among diuretic users (P for interaction: 0.08). Conclusion: Our findings suggest that UA is an independent predictor of ischemic stroke among subjects not using diuretics, but that elevated UA itself may not cause ischemic stroke. (c) 2005 Elsevier Ireland Ltd. All rights reserved.