Background <p>In patients undergoing dialysis, increased salt intake is associated with an increased risk of cardiovascular disease (CVD) events, including a higher incidence of congestive heart failure. We calculated the estimated salt intake (eSALT) using a salt intake estimation formula based on the amount of sodium removed by dialysis and investigated its relationship with patients’ prognosis.</p> Methods <p>We included 6,180 patients undergoing dialysis who attended the Zenjinkai Outpatient Clinic. We used Watson’s body water and Ramdeen’s salt estimation equations, utilizing pre- and post-dialysis blood samples collected once a month at the beginning of the week, with a 2-day interval. The eSALT was measured repeatedly in all patients, 36 times in 3 years, starting on April 1, 2016. The observational outcomes included all-cause mortality and CVD events. Statistical analyses were performed using Cox proportional hazard analysis, cubic spline curves, and Generalized Estimating Equations (GEE). Baseline and previous time-dependent repeated-measured eSALT were used in the GEE for exposure factor. The outcomes included normalized protein catabolic rate (nPCR), Geriatric Nutritional Risk Index (GNRI), and body mass index (BMI), as well as percentage change in creatinine clearance rate, blood pressure, creatinine, albumin, and uric acid.</p> Results <p>Salt intake was 8.15 g/day over 3 years. The eSALT did not predict CVD events in adjusted Cox proportional hazard analysis. Spline curves showed an increased hazard ratio for heart failure with eSALT ≥ 6 g, but not for all-cause mortality. The GEE model indicated that eSALT was associated with nutritional indices, including the GNRI, %CGR, nPCR, and BMI, from longitudinal data.</p> Conclusion <p>eSALT can be used to estimate patients’ prognosis and nutritional status. Although eSALT &gt; 6 g/day increases the risk of congestive heart failure, it improves nutritional status. This requires an increase in the uptake of other nutrients with low salt intake.</p>