Association between 24-hour urinary sodium to potassium ratio and MCI in community-based general population.

OBJECTIVE To explore the relationship between parameters of sodium and potassium excretion using 24-hour urine sample and Mild cognitive impairment (MCI) in general population. DESIGN This is a cross-sectional study. SETTING Community-based general population in Emin China. PARTICIPANTS Totally 1,147 subjects aged ≥18 years were selected to complete the study, with a multistage proportional random sampling method. Cognitive status was assessed with Mini Mental State Examination (MMSE) questionnaire and timed 24-hour urine specimens were collected. Finally, 561 participants aged ≥35 years with complete urine sample and MMSE data were included for the current analysis and divided into groups by tertiles of 24-hour urinary sodium to potassium ratio (24-h UNa/K) as lowest (T1), middle (T2), and highest (T3) groups. RESULTS The MMSE score was significantly lower in T3, compared with the T1 group (26.0 vs 25.0, P=0.002) and the prevalent MCI was significantly higher in T3 than in T1 group (11.7% vs 25.8%, P>0.001). In multiple linear regression, 24-UNa/K [β: -0.184, 95%CI: (-0.319, -0.050), p=0.007] were negatively associated with MMSE score. In multivariable logistic regression, compared with T1 group, 24-h UNa/K in the T2 and T3 group showed 2.01 (95%CI: 1.03-3.93, P=0.041) and 3.38 (95%CI: 1.77-6.44, P<0.001) fold odds for presence of MCI, even after adjustment for confounders. More augmented results were demonstrated in sensitivity analysis by excluding individuals taking anti-hypertensive agents. CONCLUSIONS Higher 24-h UNa/K is in an independent association with prevalent MCI.