Effect of two dosages of sodium chloride intake on the blood pressure response to caffeinated coffee in humans in vivo.

High sodium intake increases cardiovascular risk by increasing blood pressure. The intake of coffee elevates blood pressure acutely. Preclinical evidence shows that this action of caffeine is enhanced by high salt intake. We hypothesised that high sodium intake augments the acute blood pressure response to coffee in humans. A randomised cross-over study (n = 15) was performed comparing the effect of lower (6 g/d; LS) with higher (12 g/d; HS) sodium chloride diet on blood pressure before and 2 h after regular coffee intake. Baseline blood pressure was 115 ± 4/84 ± 2/68 ± 1 during LS and 121 ± 4/89 ± 2/69 ± 1 mmHg during HS (SBP/Mean Arterial Pressure (MAP)/DBP; mean ± SE, p < 0.05 for SBP). During LS, blood pressure increased to 121 ± 4/91 ± 2/73 ± 1 (p < 0.05 for SBP, MAP, DBP versus baseline). HS did not significantly affect the impact of coffee on blood pressure (p > 0.3 for SBP, DBP; p > 0.05 for MAP). Sodium intake does not relevantly modulate the impact of regular coffee consumption on blood pressure.