BACKGROUND: The association between sodium intake and mortality risk in the general population remains controversial. We aimed to explore the association between sodium intake and all-cause mortality in a Chinese community-based population. METHODS: A total of 6510 individuals from a Chinese community-based cohort were enrolled. 24-hour urinary sodium excretion was estimated using the Kawasaki formula. Cox proportional hazards models were used to determine the association of estimated urinary sodium excretion and spot urinary sodium with all-cause mortality. RESULTS: With a mean follow-up of 3.13 years, 65 participants (1.0%) experienced all-cause mortality. The association between estimated urinary sodium excretion and all-cause mortality appeared to be J-shaped (P for non-linearity = 0.009). Individuals were grouped in quartiles according to estimated urinary sodium excretion and spot urinary sodium. After adjusting for risk factors, the fourth quartile of estimated urinary sodium excretion (>
5.75 g/day) was associated with an increased risk of mortality compared to the second quartile (3.90 to 4.76 g/day) (hazard ratio 2.94
95% confidence interval, 1.27-6.83). Subgroup analyses revealed that current drinking status (P for interaction = 0.005) may serve as a potential modifying factor influencing the association between estimated urinary sodium excretion and all-cause mortality. There was no association between spot urinary sodium and all-cause mortality. CONCLUSIONS: Higher estimated urinary sodium excretion significantly increased all-cause mortality risk compared to moderate levels. Extremely low estimated urinary sodium excretion showed a similar trend. It is important for individuals with high sodium intake to reduce consumption to lower mortality risk. CLINICAL TRIAL NUMBER: Not applicable.