Relationship between Plasma Total Protein or Albumin Levels and Sodium-chloride Concentration Difference

Abstract

　Background: It has been reported that plasma sodium-chloride concentration difference ([Na⁺]－[Cl^-]) decreases with a decrease in plasma total protein level ([TP]) due to an increase in [Cl^-] as a compensatory response to maintain acid-base equilibrium.

　Objectives: This study aimed to verify this compensatory response.

　Methods: Overall, 156,220 datasets of [Na⁺], [Cl^-], [TP], and albumin levels ([Alb]) were collected from biochemical blood examinations performed at Saitama Municipal Hospital for two years between 2019 and 2020. The 95％ confidence intervals for the mean of [Na⁺]－[Cl^-], [Na⁺] and [Cl^-] at each value of [TP] or [Alb] were calculated. Thereafter, the regression lines of [Na⁺]－[Cl^-], [Na⁺], and [Cl^-] with respect to [TP] or [Alb] were estimated based on these confidence intervals.

　Results: The regression lines of [Na⁺]－[Cl^-] with respect to [TP] and [Alb] showed positive slope lines. Moreover, [Na⁺] and [Cl^-] changed synchronously with changes in [TP] or [Alb].

　Conclusion: [Na⁺]－[Cl^-] decreased with a decrease in [TP] or [Alb]. In addition, not only [Cl^-], but [Na⁺] also affected [Na⁺]－[Cl^-].