CORRELATION BETWEEN BLOOD PRESSURE PARAMETERS AND CEREBRAL COMPLIANCE IN HYPERTENSIVE PATIENTS

Objective: To evaluate the correlation between peripheral blood pressure measurements and intracranial pressure, considering the P2/P1 ratio as an indicator of intracranial pressure and Time to Peak (TTP) as the primary marker of cerebral compliance in hypertensive patients.Design and method: A cross-sectional study was conducted with 382 hypertensive patients (mean age 64 ± 12 years; 25.5% male). Systolic (SBP) and diastolic blood pressure (DBP) were measured in the clinic and through home blood pressure monitoring (HBPM), along with the P2/P1 ratio and TTP. Scatter plots and sex-stratified analyses were performed to explore associations. Statistical methods included Pearson correlation and ROC curve analysis, considering the sensitivity and specificity of P2/P1 (>1.56) to detect hypertension based on HBPM (>130/80 mmHg). Results: Clinic SBP showed a positive correlation with P2/P1 (r = 0.116; 95% CI 0.016–0.215), while other variables, such as total, morning, and night HBPM, showed no significant correlation. The scatter plot between the four-day average SBP and the mean P2/P1 revealed a heterogeneous distribution without a consistent pattern. ROC analysis showed an area under the curve (AUC) of 0.493 for P2/P1 (>1.56), indicating low discriminatory capacity. Sensitivity and specificity were insufficient to identify hypertension through HBPM. Agreement between P2/P1 and HBPM was 32.5%, with a Kappa coefficient of -0.12 (95% CI -0.22; -0.02). TTP showed potential as a complementary marker, reflecting the time of curve accommodation and providing additional insights into cerebral compliance. Conclusions: The results demonstrated that the P2/P1 ratio is more related to intracranial pressure than to cerebral compliance, showing low correlation with peripheral blood pressure measurements, such as HBPM. Although clinic SBP exhibited a modest correlation with P2/P1, its clinical applicability is limited due to its low discriminatory capacity and lack of agreement with HBPM parameters. This study reinforces that TTP is a more appropriate marker for assessing cerebral compliance, and it should be integrated into future studies aimed at understanding the interactions between intracranial pressure, cerebral compliance, and arterial hypertension.