Association of serum uric acid levels with cognitive function in the hypertensive population: a cross-sectional study

BACKGROUND: The association between serum uric acid (SUA) and cognitive function is controversial in previous studies. Hypertension group are prone to cognitive decline. We aimed to investigate the correlation between serum uric acid levels and cognitive function among Chinese hypertensive patients using the Chinese adapted version of Mini-Mental State Examination (CAMSE). METHODS: We included 9,471 subjects from the China Hypertension Registry study. Serum uric acid was measured using biochemical analysis instruments. The CAMSE assessment was performed to evaluate the cognitive function. Participants with different educational backgrounds used different CAMSE score cutoffs to define cognitive impairment (CI): < 24 for participants with junior high school education or above (≥ 7 years of schooling), < 20 for those with primary school education (1-6 years), and < 17 for illiterate participants. RESULTS: We enrolled 9,471 hypertensive participants (mean age 63.6 ± 9.8 years; 47.9% males, n = 4540), with mean CAMSE score22.1 ± 6.4 and SUA 428.6 ± 121.1 µmol/L. Baseline characteristics differed across SUA quartiles (all P < 0.05). Multivariable and RCS analyses showed SUA was associated with CAMSE score and CI. Fully adjusted, each one-unit lnSUA increase correlated with 0.47 higher CAMSE score (95% CI: 0.02, 0.92) and 28% lower CI (OR: 0.72; 95% CI: 0.58, 0.90). Q1 vs. Q2: 0.35 lower CAMSE score (95% CI: -0.65, -0.05) and 24% higher CI (OR: 1.24; 95% CI: 1.08, 1.43); Q3/Q4 vs. Q2 had no differences. A SUA threshold of 445.9 µmol/L was identified: below it, each lgSUA increase reduced CI by 57% (OR: 0.43; 95% CI: 0.27, 0.69). Subgroup analyses showed no interactions (all P> corrected α). CONCLUSION: There is a threshold effect of SUA level on CAMSE score and cognitive impairment in Chinese hypertensive patients. In participants with SUA < 445.9 µmol /L, decreased serum uric acid level was independently associated with cognitive decline.