The variable hyponatremic response to hyperglycemia.

Hyperglycemia may lower the plasma sodium concentration. Theoretical analyses have suggested that elevations in glucose concentration produce an invariant hyponatremic response. We propose, however, that change in plasma sodium concentration in response to hyperglycemia is variable and depends on (1) the distribution of total body water and solute, (2) the relationship between the gain of extracellular glucose and the loss of intracellular solute and (3) the intake and loss of solute and water. These factors are incorporated into a formulation of the relationship between the plasma sodium and glucose concentrations.