Correlation between ambulatory blood pressure variability and vasodilator function in middle-aged normotensive...

Area of Science:

• Cardiovascular Physiology
• Vascular Biology
• Hypertension Research

Background:

• Ambulatory blood pressure variability (BPV) is an emerging risk factor for cardiovascular events.
• Endothelial dysfunction is a key early event in atherogenesis.
• Normotensive middle-aged individuals represent a population at risk for subclinical cardiovascular changes.

Purpose of the Study:

• To investigate the association between 24-hour ambulatory blood pressure variability (BPV) and vasodilator function.
• To assess endothelial-dependent vasodilation (EDD) and endothelium-independent vasodilation (EID) in relation to BPV.
• To explore these relationships in a cohort of normotensive middle-aged individuals.

Main Methods:

• Cross-sectional study of 285 normotensive participants aged 40-59 years.
• 24-hour ambulatory blood pressure monitoring to assess systolic and diastolic BPV using coefficient of variation (CV) and average real variability (ARV).
• Brachial artery ultrasound to measure EDD and EID in response to flow and nitroglycerin, respectively; analyzed using linear regression.

Main Results:

• Higher 24-hour systolic and diastolic BPV (CV and ARV) were negatively associated with EDD in univariate analysis.
• Independent associations were found between 24-hour SBP variability (CV and ARV) and % EDD.
• BPV measures were associated with EID, but these relationships were weak and attenuated after adjusting for covariates.

Conclusions:

• Increased 24-hour blood pressure variability is independently associated with impaired endothelial-dependent and endothelial-independent vasodilator functions.
• These findings suggest BPV may contribute to early vascular dysfunction in middle-aged normotensive individuals.
• While BPV is linked to vasodilator function, the strength of these relationships is modest after accounting for other factors.