Short-term high sodium intake increases nocturnal blood pressure but not arterial stiffness in Black adults

Abstract Introduction High sodium intake has been associated with greater pressor responses in Black compared with White adults. While the acute effects of sodium on BP have been studied in Black adults, to our knowledge, no studies have explored sodium’s effects on arterial stiffness in this population. Purpose This study investigated the effects of short-term high sodium intake on BP and arterial stiffness in Black men and women. Urinary and blood markers associated with renal sodium handling were also assessed. We hypothesized that high-sodium intake would be associated with increased BP and arterial stiffness. Methods Thirty-four participants (ages 20–60 years) completed a dietary intervention consisting of 3 days of low-sodium intake (≤ 31 mmol/day) followed by 3 days of high-sodium intake (201 mmol/day). Ambulatory BP and 24-h urinary sodium excretion were measured during the final 24 h of each dietary phase and cardio-ankle vascular index (CAVI), urine specific gravity, and hematocrit were measured under fasting conditions the mornings after each 3-day dietary phase. Results Statistical analysis revealed that three days of high-sodium intake was associated with significant increases in body mass, nighttime diastolic and mean BP, and urinary sodium and sodium excretion compared to low-sodium intake ( P < 0.05 for all). Hematocrit was significantly reduced after the high-sodium dietary intervention ( P < 0.001). Arterial stiffness as measured via CAVI was unaltered. Conclusion In summary, short-term high sodium intake resulted in increased nocturnal BP without significant changes in arterial stiffness in Black men and women.