Abstract: Objective: Salt-sensitive subjects showed more frequently a non-dipper blood pressure pattern. This study aimed to investigate whether potassium supplement can improve the blunted nocturnal blood pressure fall in salt-sensitive patients exposed to high-salt diet. Methods: A total of 49 normotensive and mildly hypertensive Chinese patients received a study protocol of a 3 d baseline examination, 7 d low salt diet (51.3 mmol/d NaCl), 7 d high salt diet (307.7 mmol/d NaCl) and 7 d high salt diet with a potassium supplement (307.7 mmol/d NaCl and 60 mmol/d KCl). The blood pressure of the subjects was measured at the end of each period, and blood and urine samples were collected. The 24 h ambulatory blood pressure was also obtained. Results: Of all the 49 subjects, the detection rate of salt-sensitive individuals was 28.6%. The night-to-day blood pressure ratio was significantly higher in salt-sensitive subjects than in non-salt-sensitive ones during the high salt loading period (systolic blood pressure 0.96±0.01 vs 0.89±0.01, P<0.01; diastolic blood pressure 0.96±0.01 vs 0.92±0.01, P<0.05). Compared with the high-salt loading period, night-to-day blood pressure ratio was significantly decreased by potassium supplement in salt-sensitive subjects (systolic blood pressure 0.91±0.01 vs 0.96±0.01, P<0.05; diastolic blood pressure 0.91±0.01 vs 0.96±0.01, P<0.05). Conclusions: Potassium supplement can improve the blunted nocturnal blood pressure fall in salt sensitive patients exposed to high-salt diet.

Key words: Salt-sensitive, Ambulatory blood pressure, High salt, Potassium supplement, Night-to-day blood pressure ratio