Effects of moderate salt restriction on intralymphocytic sodium and pressor response to stress in borderline hypertension.

The effects of a moderate dietary salt restriction on intralymphocytic sodium content and pressor response to stress (mental arithmetic, handgrip, and bicycle exercise) were tested in 25 young subjects with borderline hypertension. The study was performed by a randomized, cross-over, within-patient, experimental design. Diet did not significantly reduce blood pressure at rest but did so significantly in both systolic and diastolic blood pressure during stress and exercise. Variations in diastolic blood pressure induced by stimulation correlated significantly with intralymphocytic sodium content both before and during low-salt diet whereas no correlation was found in the case of systolic blood pressure and heart rate variations. These findings suggest that in young subjects with borderline hypertension, sodium homeostasis and blood pressure regulation are somehow interrelated, and that a moderate dietary salt restriction reduces both intralymphocytic sodium content and pressor response to adrenergic stimulation. This could be useful in preventing the development of sustained hypertension.