Intralymphocytic sodium concentration: a sensitive index to identify young subjects at risk of hypertension

In subjects with borderline (BL) hypertension and in normal subjects with familial hypertension (FH), the increase in diastolic blood pressure (DBP) induced by mental arithmetic, handgrip and bicycle exercise strongly correlates with intralymphocytic sodium concentration (ILSC). In BL subjects with high or normal ILSC basal BP values are identical, but the increase in DBP during stress is significantly greater in BL subjects with high ILSC. The same phenomenon can be found in normal subjects with FH. Four hours after acute salt loading urinary Na+ is significantly higher in BL subjects with high ILSC. ILSC is a test by which one can identify BL and normal subjects with abnormal responsiveness to stimuli and who probably are fated to develop sustained hypertension.