AUTHOR=Zhou Zhike , Zhong Shanshan , Liang Yifan , Zhang Xiaoqian , Zhang Rongwei , Kang Kexin , Qu Huiling , Xu Ying , Zhao Chuansheng , Zhao Mei 

TITLE=Serum Uric Acid and the Risk of Dementia: A Systematic Review and Meta-Analysis

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=Volume 13 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2021.625690

DOI=10.3389/fnagi.2021.625690

ISSN=1663-4365

ABSTRACT=Background: This meta-analysis aimed to evaluate the relationship of serum uric acid (UA) with risk of dementia and its subtypes.
Methods: Embase, Pubmed and Web of Science were searched from inception to July 2020. Random-effects models were employed to analyze the standard mean difference (SMD) with corresponding 95% confidence intervals (CI).
Results: Twenty-three eligible studies involving 5,575 participants were identified. The overall results showed lower UA levels in dementia relative to non-dementia controls (SMD=-0.32 [-0.64;-0.01] P=0.04). Subgroup analysis of dementia type demonstrated a significant association of UA with Alzheimer’s disease (AD) (SMD=-0.58 [-1.02;-0.15] P=0.009) and Parkinson's disease with dementia (PDD) (SMD=-0.33 [-0.52;-0.14] P=0.001), but not with vascular dementia (VaD). Stratification analysis of UA concentration revealed that the UA quartile 1~2 was negatively correlated with dementia and neurodegenerative subtypes (P<0.05); whereas a positive correlation of UA quartile 4 with dementia was noted (P=0.028). Additionally, meta-regression analysis on confounders showed that not age, body mass index, diabetes mellitus, hypertension and smoking, but only education (P=0.003) exerted an influence of UA in the risk estimate of dementia.
Conclusions: Low concentration of UA (< 292 μmol/L or 4.91 mg/dL) is a potential risk factor for AD and PDD, but not for VaD. The mechanism of different UA concentration in dementia needs to be confirmed by further investigation.