Inflammatory Risk Status Shapes the Association Between Uric Acid and Cognitive Function in Non-Hyperuricemia Middle Aged and Elderly

BACKGROUND: The association between uric acid (UA) and cognitive function still remains controversial. Moreover, the role of inflammation in the above association is also unclear. OBJECTIVE: We aimed to determine the association between UA and cognitive function among non-hyperuricemia adults, and in particular, whether the association was shaped by different inflammation levels. METHODS: From the China Health and Retirement Longitudinal Study (CHARLS), 7,272 participants aged 45 and above were enrolled in 2011. Cognitive function measurement included orientation and attention, episodic memory, and visuospatial ability. Fasting blood samples were collected to measure levels of UA and high-sensitivity C-reactive protein (hs-CRP). Generalized estimating equation models were used to evaluate the effect of UA on cognitive function in all participants and those at different levels of hs-CRP (hs-CRP <3 mg/L or ≥3 mg/L). RESULTS: Among non-hyperuricemia adults (mean age: 58.08, 49.59% males) for a median of 7 years follow-up, participants with higher levels of UA had better cognitive function score compared to those with lower UA levels (β: 0.09, 95% confidence interval [CI]: 0.01-0.17, p = 0.023). And this association was significant under low-grade inflammation levels condition (β:0.10, 95% CI: 0.10-0.19, p = 0.024), but not in high-grade inflammation levels condition. Further, the cognitive function benefit of elevated UA existed only in people with persistent low-grade inflammation levels at a longitudinal perspective (β: 0.14, 95% CI: 0.01-0.27, p = 0.039). CONCLUSIONS: Elevated UA levels were associated with better cognitive function in non-hyperuricemia population, especially for those at low inflammation levels.