Urinary Sodium Excretion and the Risk of Prevalent Anemia: Nationwide Population-Based Cross-Sectional Study

Area of Science:

• Nephrology
• Cardiovascular Medicine
• Hematology

Background:

• Excessive dietary sodium is a known risk factor for cardiovascular and renal diseases.
• The association between sodium intake and anemia is not well understood.

Purpose of the Study:

• To investigate the potential link between elevated urinary sodium excretion and the prevalence of anemia.
• To explore if higher sodium excretion increases anemia risk, similar to observed benefits of certain diabetes medications on anemia.

Main Methods:

• A nationwide cross-sectional study of 54,802 adults from the Korea National Health and Nutrition Examination Survey (2014-2023).
• Participants were categorized into quartiles based on spot urine sodium-to-creatinine ratio (Na+/Cr).
• Anemia was defined using standard hemoglobin thresholds for men and women.

Main Results:

• Anemia prevalence significantly increased with higher quartiles of urinary sodium excretion (6.8% to 13.8%).
• The highest quartile of Na+/Cr showed 43% higher odds of anemia compared to the lowest (aOR 1.429).
• Each log increase in Na+/Cr was associated with a 67% increase in anemia odds (aOR 1.674).

Conclusions:

• Increased urinary sodium excretion is robustly associated with a higher prevalence of anemia in the general population.
• These findings suggest that dietary sodium restriction may have protective effects against anemia, in addition to cardiovascular benefits.