Sodium and Potassium Nutritional Status Provides a New View on the Essential Hypertension

Abstract

Short-term biological indicator of urinary Na and K excretion is generally used to assess Na and K dietary exposure. In this study, we used the long-term biological indicator of hair to assess Na and K nutritional status. Hair Na and K were analyzed in 1073 healthy adult white Caucasians [734 women (♀) and 339 men (♂)] with the ICP MS. The log-transformed data were analyzed with median derivatives bioassay. The median values (μg∙g−1) were ♀Na 254 and ♂Na 371, and ♀K 74.3 and ♂K 143, respectively. The linear (adequate) ranges of the sigmoid saturation curve ranges for sodium were ♀Na 55.6–1307 and ♂Na 84.0–1450, whereas these ranges for potassium were ♀K 18.9–467 and ♂K 25.8–1079. The strict homeostatic control of whole blood K and Na renders them unsuitable for assessing the nutritional status. The potassium to sodium ratio (K/Na) in women appears stable across the sigmoid linear segment range, contrary to the constantly increasing K/Na ratio in Men. The results suggest that hair Na concentration should not be below 55.6 and 84.0 or above 1307 and 1450 μg∙g-1 in women and men, respectively. Similarly, K hair concentrations should not be below 18.0 and 25.8 and higher than 46.7 and 107.9 in women and men, respectively. Hair K/Na ratio should stay about 0.600 in M and 0.400 in W. Current dietary salt exposure of the general US population does not require preventive across the board salt restriction.