Association Of Serum Uric Acid Level And Cognitive Impairment In Parkinson’s Disease:a Meta-analysis

Objective:To exlore the relationship between serum uric acid level and cognitive function of Parkinson’s disease patients.Methods:We searched papers that focused on the correlations between serum uric acid and the cognition impairment or dementia of PD in PubMed、CNKI and Wanfang database with a time limit from the day database built to the 15th of January 2016.We demanded all the papers involved in this study be case control studies. At the same time,we checked the all the papers’ references about the issue to ensure the recall ratio,and using google scholar database as an alternative to acquire the papers.There are 2 experts responsible for the screening of the paper by reading,analysing and evaluating all the papers carefully according to the including and excluding criterions using Review Manager 5.3 software to conduct Meta analysis on the literatures matched with conditions.Then we judged the results by Forest plot and Begger’s funnel plot.Results:In the study,8 papes were included eventually, and the number of PD patients with cognitive dysfunction was 335 while 327 of PD without cognitive dysfunction 327,and the normal control group involved 637 individuals.To analysis the relationship between serum uric acid level and cognitive impairment or dementia in Parkinson’s disease.Comparing the serum uric acid level of the PD with cognitive dysfunction group and PD without cognitive dysfunction group, at first, we conducted heterogeneity test, the results showed that Chi2=29.10, df=7, P= 0.005,12=65%.p< 0.05,indicating that heterogeneity exist among the data.Then we selected the random effects model to analysis the data, the result is MD=-61.55, and its 95% confidence interval (CI)is [-74.75～-48.35], Z=9.14,p<0.00001, having statistical significance, that is to say, PD with cognitive dysfunction group compared with PD without cognitive impairment group, there is a significant difference on the level of serum uric acid. The serum uric acid level of PD’s cognitive dysfunction group compared with normal control group, coducting heterogeneity test, the results is Chi2=7.72, df=7,p= 0.36, P=9%<50%,p> 0.05, from which we can know that there is no obvious heterogeneity about the studies.Then we choose fixed effect model to analysis our datas. The results showed that MD=-1O5.35 and its 95% CI is[-112.33 98.37], Z=29.57,p<0.00001, having statistical significance, namely Parkinson’s disease cognitive dysfunction group compared with normal control group, there is a significant difference on the level of serum uric acid. We detect publication bias by using Begger’s funnel plots. Publication bias was detected by s’ Begger funnel plot, and the results showed that there was no significant publication bias. By using different statistical models to analyze the same data to detect the data’s sensitivity, the results showed that the sensitivity was low, and the results were robust and credible.Conclusion:1、There is a significant difference between the level of serum uric acid in Parkinson’s disease cognitive dysfunction group and Parkinson’s disease without cognitive impairment group. The serum uric acid level of Parkinson’s disease cognitive dysfunction group can be considered as lower than that of Parkinson’s disease without cognitive impairment group.2、There is a significant difference between the level of serum uric acid in Parkinson’s disease cognitive dysfunction group and normal control group. The serum uric acid level of Parkinson’s disease cognitive dysfunction group can be considered as lower than that of normal control group.