White-coat effect in normotension and hypertension

Area of Science:

• Cardiology
• Hypertension Research
• Diagnostic Monitoring

Background:

• The white-coat effect is defined as the difference between clinic and daytime ambulatory blood pressure measurements.
• Understanding the white-coat effect's behavior across different blood pressure ranges is crucial for accurate hypertension diagnosis.
• Its association with cardiovascular structural changes like left ventricular mass requires further investigation.

Purpose of the Study:

• To investigate the magnitude of the white-coat effect in relation to varying daytime ambulatory blood pressure levels.
• To examine the association between the white-coat effect and left ventricular mass.
• To identify blood pressure thresholds where the white-coat effect changes significantly.

Main Methods:

• 1581 subjects underwent clinic blood pressure readings, 24-h ambulatory blood pressure monitoring, and echocardiography.
• Daytime systolic and diastolic blood pressure levels ranged from 88.0–208.9 mmHg and 40.3–133.0 mmHg, respectively.
• Statistical analyses were performed to correlate white-coat effect with ambulatory blood pressure and left ventricular mass.

Main Results:

• A significant inverse correlation was observed between the white-coat effect and daytime ambulatory blood pressure (systolic r = -0.22, diastolic r = -0.50).
• Left ventricular mass correlated with ambulatory blood pressure but not with clinic blood pressure or the white-coat effect.
• The white-coat effect reversed at high daytime ambulatory blood pressure levels (systolic > 170 mmHg or diastolic > 100 mmHg).

Conclusions:

• The white-coat effect demonstrates an inverse relationship with daytime ambulatory blood pressure.
• It is most prominent at daytime ambulatory blood pressure levels below 140/80 mmHg.
• The effect is reversed at levels exceeding 170/100 mmHg, indicating a potential shift in measurement dynamics at higher pressures.