PSYCHOPHYSIOLOGICAL REACTIVITY OF SALT-SENSITIVE NORMOTENSIVE SUBJECTS

Objective To evaluate the psychophysiological response to mental stres s of young healthy salt-sensitive normotensive subjects. Methods Thirt y-two healthy volunteers who had previously been phenotyped for salt s ensitivity were selected for the study, The 16 salt-sensitive and 16 s alt-resistant subjects, who were matched for age, body mass index and family history of hypertension, underwent a mental stress test consist ing of an information-processing task performed under time pressure (t he Manometer test), During the experimental session the blood pressure , heart rate and pulse-wave velocity were registered continuously, Bef ore and after the mental task subjects were instructed to complete sev eral standardized psychological state and trait questionnaires. Result s Mental stress resulted in a greater rise in blood pressure (P < 0.05 ) and in pulse-wave velocity (P < 0.01) in salt-sensitive than in salt -resistant individuals. Salt-sensitive subjects also displayed signifi cantly higher levels of anxiety (P < 0.01) and a lower level of contro l of anger (P < 0.01) than did salt-resistant subjects. Furthermore, t he level of irritation of the salt-sensitive subjects was higher both before (P < 0.01) and after (P < 0.05) the stress test. Conclusions An increased responsiveness of the blood pressure to mental stress and a n increased level of irritation are associated with salt sensitivity i n normotensive subjects, These findings are in line with the hypothesi s that psychophysiological traits play a role in the development of sa lt-sensitive hypertension.