Association between autonomic dysfunction and arterial stiffness in hypertensive patients

The purpose of this study was to investigate whether heart rate variability (HRV), a predictor of autonomic function, is associated with arterial stiffness in hypertensive patients. A total of 1,132 essential hypertension patients were included in this retrospective study. The standard deviation of normal-to-normal intervals (SDNN), an indicator of HRV, was selected to assess autonomic function. Arterial stiffness was evaluated by measuring the brachial-ankle pulse wave velocity (baPWV). Patients were categorized into tertiles based on their SDNN values. Participants in the lowest tertile of SDNN were older and exhibited higher levels of triglycerides and fasting blood glucose compared to those in the highest tertile of SDNN. Multivariate linear regression analyses indicated that SDNN had an independent negative correlation with baPWV (β=-3.60; 95% confidence interval [CI] =-4.78 ~ -2.41) after adjusting for all covariates. Consistently, multiple logistic regression analyses revealed a negative relationship between SDNN and the elevated baPWV (>75th percentile) (odds ratio [OR]=0.97; 95% CI=0.95 ~ 0.99). Evaluations utilizing restricted cubic splines confirmed that the relationships between SDNN and baPWV displayed an L-shaped curve (non-linear, P<0.001). Subgroup analyses indicated that more pronounced associations between SDNN and baPWV were observed in younger individuals (under 65 years) (P for interaction< 0.05). This study demonstrated that the SDNN is independently and negatively associated with baPWV in hypertensive patients, particularly in those under 65 years of age. These findings suggest a potential relationship between arterial stiffness and autonomic nervous system function.