Study of synchronic heart rate variability and blood pressure variability and carotid-femoral pulse wave velocity in hypertensive patients with varying salt sensitivy

AIM To investigate the association between cardiac autonomic function and arterial stiffness in patients with hypertension with different salt sensitivity. METHODS From 2011 to 2014, 315 patients with EH whose blood pressure had been controlled to a nomal level and admitted to a cardiovascular ward were enrolled in the study. Synchronic 24 hour ambulatory blood pressure monitoring (ABPM) and dynamic electrocardiogram (Holter), carotid-femoral pulse wave velocity (PWV), were performed for all participants. The 315 patients were divided into 3 groups according to the 24 hour heart rate and blood pressure circadian rhythm as low, medium, and high risk group of salt sensitivity. RESULTS There were increased 24-hour systolic blood pressure standard deviation (24hSSD) (P<0.05) and decreased standard deviation of the average of all normal-to-normal intervals in all 5-minute intervals (SDANN) (P<0.05) in the risker group of salt sensitivity. The HRV analysis revealed that SDANN significantly decreased and LF, LF/HF increased in risker group of salt sensitivity (P<0.05). Analyzing the data of ABPM showed that 24hSSD, dSSD, nSSD are significantly higher than in the low risk group (P<0.05). Night/day heart rate ratio were significantly higher in risker group of salt sensitivity (P<0.05). Spearman analysis revealed that salt sensitivity is correlated with PWV, 24hSSD, LF, LF/HF and Night/day heart rate ratio. Multiple regression analysis showed that the risk of salt sensitivity is independently correlated withPWV, 24hSSD, LF, LF/HF and Night/day heart rate ratio. CONCLUSION The salt sensitivity is an independent factors of Sympathetic nervous system activity (LF), autonomic nervous system dysfunction (LF/HF) and arterial stiffness in patients with EH.