Correlation between blood pressure responses to dietary sodium and potassium intervention in a Chinese population

Abstract

Background: Blood pressure (BP) responses to dietary sodium and potassium intake vary among individuals. We examined the correlation between BP responses to dietary low-sodium, high-sodium, and potassium supplementation interventions in a feeding study.

Methods: A total of 1,906 Chinese aged > or = 16 years participated in the dietary intervention that included a 7-day low-salt intervention (51.3 mmol/day), a 7-day high-salt intervention (307.8 mmol/day), and a 7-day high-salt plus potassium supplementation (60 mmol/day) intervention. BP was measured nine times during the 3-day baseline observation and during the last 3 days of each intervention phase using a random-zero sphygmomanometer.

Results: The correlation coefficients (95% confidence intervals (CIs)) of the BP responses to low-sodium and high-sodium interventions were -0.47 (-0.51 to -0.44), -0.47 (-0.50 to -0.43), and -0.45 (-0.49 to -0.42) for systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP), respectively (all P < 0.0001). The correlation coefficients (95% CI) of the BP responses to high-sodium intervention and potassium supplementation were -0.52 (-0.56 to -0.49), -0.48 (-0.52 to 0.45), and -0.52 (-0.55 to -0.48) for SBP, DBP, and MAP, respectively (all P < 0.0001). The kappa coefficients were moderate, varying from 0.28 to 0.34, between BP responses to low-sodium and high-sodium interventions (all P < 0.0001).

Conclusions: These results indicate there is a moderate correlation between BP responses to low-sodium and to high-sodium interventions, and BP responses to high-sodium intervention and potassium supplementation. Furthermore, our study suggests that individuals who were more sensitive to high-sodium diet might benefit more from a low-sodium and/or high-potassium intervention aimed at lowering BP levels.

Figure1

Scatter plots of blood pressure responses to low sodium and high sodium interventions (upper panel for systolic pressure, middle panel for diastolic pressure, and lower panel for mean arterial pressure).

Figure2

Scatter plots of blood pressure responses to high sodium intervention and potassium supplementation (upper panel for systolic pressure, middle panel for diastolic pressure, and lower panel for mean arterial pressure).