Association of serum uric acid and fasting plasma glucose with cognitive function: a cross-sectional study

Background The combined effect of serum uric acid (SUA) and blood glucose on cognition has not been explored. This study aimed to examine the separate and combined association of SUA and fasting plasma glucose (FPG) or diabetes mellitus (DM) with cognition in a sample of Chinese middle-aged and elderly population. Methods A total of 6,509 participants aged 45 years or older who participated in the China Health and Retirement Longitudinal Study (CHARLS, 2011) were included. The three cognitive domains assessed were episodic memory, mental status, and global cognition (the sum of the first two terms). Higher scores indicated better cognition. SUA and FPG were measured. The participants were grouped based on SUA and FPG quartiles to evaluate their combined associations of cognition with SUA Q1–Q3 only (Low SUA), with FPG Q4 only (High FPG), without low SUA and high FPG levels (Non), and with low SUA and high FPG levels (Both), multivariate linear regression models were used to analyze their association. Results Lower SUA quartiles were associated with poorer performance in global cognition and episodic memory compared with the highest quartile. Although no association was found between FPG or DM and cognition, high FPG or DM combined with low SUA levels in women (β FPG = -0.983, 95% CI: -1.563–-0.402; β DM = -0.800, 95% CI: -1.369–-0.232) had poorer cognition than those with low SUA level only (β FPG = -0.469, 95% CI: -0.926–-0.013; β DM = -0.667, 95% CI: -1.060–-0.275). Conclusion Maintaining an appropriate level of SUA may be important to prevent cognitive impairment in women with high FPG.