Time rate of blood pressure variation is superior to central hemodynamics as an associate of carotid intima-media thickness.

OBJECTIVE

The extent of target organ damage has been associated with both central hemodynamics and arterial stiffening, and the time rate of blood pressure (BP) changes in essential hypertension. However, the relative significance of these parameters has not been examined.

METHODS

We recruited 232 consecutive uncomplicated newly diagnosed hypertensive patients and 241 normotensive individuals. Twenty-four-hour ambulatory BP monitoring was performed in all individuals. The time rate of SBP variation was computed as the first derivative of the SBP values against time. Aortic central SBP and central DBP, central pulse pressure, central augmentation index and central augmentation pressure were assessed noninvasively by pulse wave analysis. Common carotid artery intima-media thickness was measured by high-resolution ultrasonography.

RESULTS

Median 24-h time rate of BP changes was 0.571 +/- 0.114 mmHg/min. Traditional risk factors, office SBP, several ambulatory BP monitoring parameters (24-h SBP, 24-h pulse pressure, 24-h heart rate and BP dipping), 24-h time rate of BP changes, time rate of BP changes at different time intervals, and central SBP, central pulse pressure, central augmentation index and central augmentation pressure significantly correlated with intima-media thickness. Age, sex, BMI, 24-h time rate of BP changes, time rate of BP changes measured at 0100-0600 h and 24-h heart rate remained significant associates of intima-media thickness after adjustment for confounding factors. By multivariate stepwise linear regression, 24-h time rate of BP changes and time rate of BP changes at 0100-0600 h had incremental value over traditional risk factors, other ambulatory BP monitoring parameters and central hemodynamics.

CONCLUSION

These findings indicate that time rate of BP variation is superior to central hemodynamics as an associate of carotid intima-media thickness in hypertensive and normotensive individuals.