The blood pressure lowering effect of lactotripeptides and salt intake in 24-h ambulatory blood pressure measurements.

It is well known that the sour milk containing lactotripeptides has a blood pressure lowering effect. The aim of this study was to evaluate the blood pressure (BP) lowering effect of lactotripeptides by monitoring home blood pressure, 24-h ambulatory measurements (ABPM), and daily urinary salt excretion. A total of 30 volunteers were given 200 ml of sour milk twice a day for 8 weeks after a 1-week run-in period. This preparation contained the lactotripeptides valine-proline-proline 2.66 mg and isoleucine-proline-proline 1.38 mg. The study participants had daily measurements of urinary salt excretion determined by an electric salt sensor and home blood pressure for each week during the run-in period, before the 4-and 8-week time points. 24-h ABPM was measured at the end of each week. Mean systolic blood pressure (SBP) during night sleep including base BP at 4 and 8 weeks were significantly lower than baseline values. Mean SBP and diastolic blood pressure (DBP) during night sleep of the 22 participants who belonged to the criteria of hypertension by 24-h ABPM was significantly decreased at 4 and 8 weeks. The change in 24-h mean SBP significantly correlated with mean urinary salt excretion over the three measurement periods. The 22 hypertensive subjects without taking lactotripeptides did not show significant change of blood pressure during 24 hours at 4 and 8 weeks. Our study confirmed the BP lowering effect of lactotripeptides during night-time sleep and showed that a lower intake of salt may increase the BP lowering effect of lactotripeptides through 24 hours in hypertensive subjects.