Dietary sodium, potassium reduce short-term BP variability

Dietary intake of sodium and potassium can control short-term blood pressure variability (BPV) in addition to BP, reveals a recent study. Combined Dietary Approaches to Stop Hypertension (DASH) diet and low sodium intake may also lower systolic and diastolic average real variability (ARV) through various mechanisms.

In this study, the investigators included 343 participants from the DASH-Sodium trial (mean age 48.4 years, 42.5 percent men) and 323 individuals from the Jackson Heart Study (mean age 56.7 years, 30.7 percent men) with satisfactory ambulatory BP monitoring records and 24-h urine collection. They also calculated ARV as a measure of short-term BPV.

Estimation of dietary intake from urinary excretion showed that higher urinary sodium-to-potassium ratio significantly correlated with higher diastolic ARV in both studies.

In the DASH-Sodium trial, potassium-rich DASH diet alone had no significant impact on both systolic (–0.1±1.7 mm Hg; p=0.343) or diastolic ARV (–0.2±1.5 mm Hg; p=0.164), while combined DASH diet and low sodium intake resulted in a significant reduction in both systolic (8.5±1.6 vs 8.9±1.7 mm Hg; p=0.032) and diastolic ARV (7.5±1.5 vs 7.8±1.6 mm Hg; p=0.025) when compared to control diet and high sodium intake.

Decrease in systolic ARV was primarily derived from the change of mean SBP. Thus, urinary sodium-to-potassium ratio significantly determined diastolic ARV (β coefficient ± standard error, 0.012±0.004; p=0.006) after adjusting for age, sex, smoking, mean diastolic BP, body mass index, and race.

“DASH-Sodium trial showed that dietary sodium and potassium affect BP,” the investigators noted.