Effect of long-term blood pressure control on salt sensitivity

The objective of this study was to reevaluate salt sensitivity (SENS) after a period of antihypertensive treatment (AT). SENS was measured in ten patients, before and after 18 +/- 6 months on AT. The average for all mean blood pressures (MBP) measured during AT was used as an index of blood pressure (BP) control. After at least eight weeks on placebo only, all patients were submitted to an ad libitum diet (ALD), low salt diet (LSD), and high salt diet (HSD) during one week each. SENS was considered as the percent change of the MBP between the seventh day of LSD and HSD. Weight, BP, and daily urinary Na+ and K+ excretion (mean of seven days) on ALD were the same in the first (F) and second (S) evaluation. SENS did not significantly change from the F and S measurement. An inverse correlation was obtained between individual SENS difference and the average mean blood pressure (AMBP) (r = -0.85, p = 0.0018). In conclusion, patients who showed greater decreases in SENS were the ones with the best BP control.