Relationship between serum sodium level at dialysis initiation and all-cause mortality

Area of Science:

• Nephrology
• Internal Medicine
• Clinical Research

Background:

• Hyponatremia is a frequent complication in chronic kidney disease (CKD) patients.
• This electrolyte imbalance is associated with higher mortality rates, particularly in patients undergoing dialysis.
• Limited research exists on the mortality risk of hyponatremia specifically in patients initiating dialysis.

Purpose of the Study:

• To investigate the association between serum sodium levels at dialysis initiation and all-cause mortality.
• To identify the prognostic significance of hyponatremia in incident dialysis patients.

Main Methods:

• A prospective cohort study included 1520 patients initiating dialysis.
• Patients were categorized into five serum sodium groups: <130, 130-134, 135-139, 140-144, and ≥145 mEq/L.
• Multivariate Cox proportional hazards models were used to analyze factors associated with all-cause mortality.

Main Results:

• A total of 392 deaths occurred during the follow-up period.
• Patients with the lowest (<130 mEq/L) and highest (≥145 mEq/L) serum sodium levels showed higher ultrafiltration volumes.
• All-cause mortality risk was significantly elevated in patients with serum sodium <130 mEq/L compared to those with 135-139 mEq/L (HR: 1.61, 95% CI: 1.04-2.49).

Conclusions:

• Hyponatremia (<130 mEq/L) at the start of dialysis is a significant predictor of all-cause mortality.
• Underlying conditions like cardiovascular disease and medication use may contribute to this association.
• These findings highlight the importance of monitoring and managing serum sodium levels in patients initiating dialysis.