Abstract
OBJECTIVES: Blood pressure variability (BPV) and heart rate variability (HRV) are well-established indicators of autonomic functioning. However, the regulation of cardiac autonomic homeostasis differs between the sexes remains unknown. In this study, we explored the association between BPV and HRV in patients with isolated primary hypertension, with an emphasis on sex-related differences. We aimed to facilitate clinical practice by informing sex-specific diagnostic and therapeutic approaches for managing primary hypertension through our study. METHODS: A retrospective analysis was conducted on 189 individuals (85 males, 104 females) diagnosed with isolated primary hypertension at the Xuancheng People's Hospital from December 2020 to March 2023. All participants underwent 24-hours ambulatory blood pressure and Holter electrocardiogram monitoring. Correlation analyses, including multiple linear regression and Pearson/Spearman tests, were conducted to assess the relationship between BPV and HRV, with an emphasis on sex-based comparisons. RESULTS: Among males, the 24-hours standard deviation of systolic blood pressure (24hSSD) was significantly associated with age, plasma glucose levels, and HRV metrics, including rMSSD and total power (p < 0.05). Conversely, in females, 24hSSD was positively linked to age and negatively associated with the heart rate and pNN50, which represents the percentage of RR intervals exceeding 50 ms. The data indicated stronger BPV-HRV correlations in males than in females. CONCLUSIONS: Distinct sex-based differences were identified in the relationship between BPV and HRV in primary hypertension. Males demonstrated stronger interconnections between these variables, while the associations in females were comparatively weaker. These findings highlight the importance of developing tailored, sex-specific management strategies to enhance the treatment and outcomes for individuals with primary hypertension.