(LB03-08-26) Relationship Between Dietary Sodium, Potassium, and the Systemic Immune-Inflammation Index in Healthy Adults: An Observational Study

Objectives: The Systemic Immune-Inflammation Index (SII), calculated from platelet, neutrophil, and lymphocyte counts, is a validated marker of systemic inflammation linked to cardiovascular and all-cause mortality. Electrolytes, particularly sodium and potassium, play a role in immune regulation, with high sodium intake proposed to promote pro-inflammatory pathways and contribute to atherosclerosis development. However, human studies on sodium intake and inflammation show mixed findings. Studies in young healthy adults are needed to minimize confounding from comorbidities. To address this gap, our preliminary study tested whether dietary potassium is inversely associated with SII, and whether dietary sodium and Na:K ratio are positively associated with SII in young healthy adults.

Methods: Eleven young healthy adults (age 22.8±3.5) were included in this cross-sectional study. Sodium, potassium, and Na:K ratio were assessed using 3-day diet records, and SII was calculated from fasting blood samples using automated hematology. Normality was confirmed via Shapiro-Wilk test (all p >0.05). Pearson bivariate correlations, partial correlations controlling for sex, and hierarchical regression analysis were conducted using SPSS. Significance was set at p< 0.05.

Results: Pearson correlations showed significant negative correlations between SII and sodium intake (r = -0.64, p = 0.04) and SII and Na:K ratio (r= -0.065, p= 0.03). Potassium intake was not correlated with SII (r= -0.245, p = 0.47). Partial correlations controlling for sex produced similar outcomes (Na, r = -0.654, p = 0.04; Na:K ratio, r = -0.64, p = 0.045). Hierarchical regression showed sodium explained 42.6% of additional SII variance beyond sex (ΔR²=0.426, p=0.04, β=−0.692), and Na:K ratio explained 41.3% (ΔR²=0.413, p=0.045, β=−0.646). Potassium did not significantly predict SII (ΔR²=.056, p=0.51).

Conclusions: Contrary to predictions, sodium and Na:K ratio were inversely correlated with SII in healthy young adults. This may be due to effective sodium regulation in healthy individuals, whereas sodium promotes inflammation in clinical populations. Potassium was not related to SII, which suggests that its effect may depend upon sodium-potassium balance. These results warrant future investigation.

Funding Sources: None