Assessment of risk of hypertension and methods based thereon

An in vitro method of analyzing whether the blood pressure of a subject is sensitive to sodium intake, the method comprising:

• (a) suspending erythrocytes of the subject in one or more pairs of a first solution of about physiological osmolality and a second solution of about physiological osmolality, each first solution and each second solution comprising at least one of sodium chloride and potassium chloride,
• wherein for each pair of first and second solution the first solution comprises sodium chloride, and the second solution comprises sodium chloride or potassium chloride,
• wherein a second solution comprising sodium chloride has a sodium chloride concentration that is at least about 25 mM higher than the sodium chloride concentration of the first solution, and
• wherein a second solution comprising potassium chloride has a concentration of potassium chloride that is of at least essentially about the same value as the concentration of sodium chloride in the first solution;
• (b) allowing the suspended erythrocytes in the first and in the second solution of at least one pair of first and second solution to settle for a period of time sufficient to allow the formation of a supernatant;
• and
• (c) detecting the difference in height of the supernatant between the first and the second solution of the at least one pair of first and second solution,
• wherein an increased difference in height of the supernatants of the at least one pair of first and second solution, relative to a threshold value, indicates that the blood pressure of the subject is sensitive to sodium intake.