Sodium intake, serum sodium levels and impact on overhydration of patients on hemodialysis.

OBJECTIVE

Evaluate the relationship between dietary intake, dietary and serum sodium, Interdialytic weight gain (IDWG), and overhydration in hemodialysis (HD) patients.

METHODS

This observational, longitudinal study includes 582 patients from 37 Portuguese HD centers. Correlations between sodium intake, serum sodium, hyperhydration, dietary intake, and IDWG were analyzed using Spearman's coefficient. Mann-Whitney U test analyzed associations of dietary and serum sodium and IDWG with relative overhydration (≥15 % or <15 %). Logistic regression assessed the impact of serum sodium and dietary intake on hyperhydration. Cox regression assessed the association of hyperhydration with mortality risk at 24 months. Multiple linear regression explored relationships between GPI, sodium intake, and blood pressure. Significance level adopted: p < 0.05.

RESULTS

Sodium intake correlates with blood pressure. People with hyperhydration have higher IDWG. Some foods showed correlations with dietary and serum sodium, IDWG and relative overhydration. Consumption of bacon, savory snacks, carrots, bell peppers, cherries, and soup predicted greater hyperhydration, while rice, cookies, and grapes show the opposite effect, regardless of age, sex, diabetes, and HD duration.

CONCLUSION

IDWG is associated with hyperhydration, and sodium intake correlates positively with blood pressure. Certain foods influence serum sodium, IDWG, and the risk of hyperhydration, highlighting the need for personalized dietary strategies to optimize hydration management in HD patients.