We evaluated the relationship of daily
coffee intake with endothelial function assessed by flow-mediated vasodilation and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation in patients with
hypertension. A total of 462 patients with
hypertension were enrolled in this cross-sectional study. First, we divided the subjects into two groups based on information on daily
coffee intake: no
coffee group and
coffee group. The median
coffee intake was two cups per day in the
coffee group. There were significant differences in both flow-mediated vasodilation (2.6 ± 2.8% in the no
coffee group vs. 3.3 ± 2.9% in the
coffee group, p = 0.04) and nitroglycerine-induced vasodilation (9.6 ± 5.5% in the no
coffee group vs. 11.3 ± 5.4% in the
coffee group, p = 0.02) between the two groups. After adjustment for confounding factors, the odds ratio for endothelial dysfunction (OR: 0.55, 95% CI: 0.32-0.95) and the odds ratio for vascular smooth muscle dysfunction (OR: 0.50, 95% CI: 0.28-0.89) were significantly lower in the
coffee group than in the no
coffee group. Next, we assessed the relationship of the amount of daily
coffee intake with vascular function. Cubic spline curves revealed that patients with
hypertension who drank half a cup to 2.5 cups of
coffee per day had lower odds ratios for endothelial dysfunction assessed by flow-mediated vasodilation and vascular smooth muscle dysfunction assessed by nitroglycerine-induced vasodilation. Appropriate daily
coffee intake might have beneficial effects on endothelial function and vascular smooth muscle function in patients with
hypertension.