The relationship between circadian rhythm of blood pressure and vascular dysfunction in essential hypertension

Objective This study aimed to explore whether circadian rhythm of blood pressure is associated with brachial-ankle pulse wave velocity (baPWV) and brachial artery flow-mediated dilation (FMD) in patients with essential hypertension. Method This cross-sectional study included 4,217 patients with essential hypertension who completed 24-hour ambulatory blood pressure monitoring, baPWV, and FMD. BaPWV and FMD were measured to evaluate arterial stiffness and endothelial dysfunction. Participants were divided into dipper, non-dipper, and reverse dipping groups according to the nocturnal systolic blood pressure dipping percentage. Results In this study, baPWV was highest in the reverse dipping groups, followed by non-dipper and dipper groups (1667.11 & PLUSMN; 327.90 vs. 1613.88 & PLUSMN; 325.11 vs. 1577.45 & PLUSMN; 306.15 cm/s, P < .001) and FMD gradually increased (4.41 & PLUSMN; 2.87 vs. 4.70 & PLUSMN; 2.84 vs. 4.92 & PLUSMN; 2.79%, P = .001). baPWV and FMD were significantly associated with declining nocturnal systolic blood pressure (SBP). Interestingly, FMD (& beta; = 0.042, P = .014) was only positively associated with a drop in nocturnal SBP decline in patients <65 years of age. Whereas baPWV was consistently negatively associated with nocturnal SBP decline regardless of age (& beta; = -0.065, P < .001, age <65 years; & beta; = -0.149, P = .002, age & GE; 65). Receiver operating characteristics (ROC) curves analysis showed areas under the curve (AUC) of baPWV/FMD for predicting circadian rhythm of blood pressure are 0.562/0.554 with a sensitivity of 51.7%/53.9% and specificity of 56.4%/53.4. Conclusion Impairment of baPWV and FMD were correlated with abnormal circadian rhythm of blood pressure in essential hypertension, suggesting a decrease in nighttime SBP may associate with endothelial function and arterial stiffness.

Automated summary

This study found that the circadian rhythm of blood pressure is associated with arterial stiffness and endothelial dysfunction in patients with essential hypertension. The results showed that baPWV was highest in the reverse dipping group, followed by the non-dipper and dipper groups. Additionally, endothelial function improved with increased nocturnal blood pressure decline. Therefore, a decrease in nighttime systolic blood pressure may be associated with endothelial function and arterial stiffness.