Association Between Serum Uric Acid And The Risk Of First Stroke

Objective:Whether serum uric acid is a risk factor for stroke is uncertain.Present study was conducted with the aim of exploring the association between serum uric acid and first stroke and its subtypes in hypertensive patients.Methods:This study is a nested case-control study designed on the study of“H-type hypertension and stroke prevention and control project”（HSPCP）.HSPCP was a non-intervention,prospective,community-based observational study.From January2017 to December 2017,300000 cases of participants were screened in Rongcheng of Shandong Province and Lianyungang of Jiangsu Province altogether.In the end of December 31,2018,the new stroke cases were matched with the new Diseases Diseases Controls（CDC）based on the identity card number and was established as stroke group.Then,participants in control group were matched equivalently according to gender,age（±1 years old）and area in those without stroke.Finally,3479pairs of patient were included in the analysis.Conditional logistic regression and smooth fitting curve were used to evaluate the relationship between serum uric acid and first stroke and its subtypes.Results:A total of 6958 subjects（3122 males and 3836 females）were included in this study.The level of serum uric acid was not significant in males between the case group and the control group（P>0.05）,but was statistically significant in women between the case group and the control group（P<0.05）.For men,when serum uric acid was used as a continuous variable,conditional logistic regression analysis showed that there was no significant association between serum uric acid and first total stroke（OR:1.01,95%CI:0.96-1.06,P=0.755）,first ischemic stroke（OR:0.99,95%CI:0.94-1.05,P=0.794）and first hemorrhagic stroke（OR:1.11,95%CI:0.91-1.34,P=0.300）.According to the level of uric acid,it was further divided into four groups.Compared with uric acid group Q1（<5.1 mg/dl）,Q2（5.2-6.1 mg/D）,Q3（6.1-7.1 mg/dl）and Q4（≥7.1 mg/dl）did not significantly increase the incidence of first stroke,first ischemic stroke and first hemorrhage stroke.For women,when serum uric acid was used as a continuous variable,the risk of total stroke,ischemic stroke and hemorrhagic stroke increased by 7%（OR:1.07,95%CI:1.02-1.13,P=0.01）,7%（OR:1.07,95%CI:1.01-1.13,P=0.02）and 10%（OR:1.10,95%CI:0.94-1.29,P=0.227）respectively for each unit of serum uric acid increase.Uric acid level was also further divided into quartiles.Compared with uric acid Q1group（<4.3 mg/dl）,the risk of first total stroke in Q2（4.3-5.1 mg/D）,Q3（5.1-6.0mg/dl）and Q4（≥6.0 mg/dl）groups was increased by 16%（OR:1.16,95%CI:0.96-1.41,P=0.125）,12%（OR:1.12,95%CI:0.92-1.36,P=0.263）and 44%(OR:1.44,95%CI:1.18-1.76,P<0.001;P _trend=0.001)respectively,The risk of ischemic stroke increased by 20%（OR:1.20,95%CI:0.98-1.47,P=0.077）,12%（OR:1.12,95%CI:0.91-1.37,P=0.298）and 48%（OR:1.48,95%CI:1.19-1.83,P<0.001;P trend=0.002）.Although the risk of hemorrhagic stroke increased,it was no significant difference.Conclusion:Our data suggested that elevated uric acid was an independent risk factor for total stroke and ischemic stroke in women,but not in men,among Chinese hypertensive patients.