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Relationship of arterial compliance to baroreflex function in hypertensive patients
S G Lage1, J F Polak, D H O'Leary
1Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.
Insights
Hypertension is linked to reduced carotid arterial compliance and impaired arterial baroreflex function in patients. These findings highlight the connection between vascular stiffness and the body's blood pressure regulation system.
Area of Science:
- Cardiovascular Physiology
- Hypertension Research
Background:
- Hypertension is a major risk factor for cardiovascular disease.
- Arterial stiffness and baroreflex dysfunction are implicated in hypertension pathogenesis.
Purpose of the Study:
- To investigate reduced carotid arterial compliance in hypertensive patients.
- To assess the relationship between arterial compliance and baroreflex function in hypertension.
Main Methods:
- Carotid arterial compliance measured using high-resolution B-mode ultrasonography.
- Arterial baroreflex function assessed via nitroprusside and phenylephrine infusions.
- Concurrent measurements of blood pressure and carotid arterial diameter.
Main Results:
- Hypertensive patients exhibited significantly lower carotid arterial compliance compared to normotensive subjects (P < 0.001).
- Hypertensive individuals showed a reduced baroreflex slope, indicating impaired baroreflex sensitivity (P < 0.05).
- A significant correlation was found between baroreflex slope and arterial compliance across all subjects (r = 0.53, P < 0.05).
Conclusions:
- Reduced carotid arterial compliance is a characteristic of hypertension.
- Impaired arterial baroreflex function is associated with reduced arterial compliance in hypertensive individuals.
- Age correlates negatively with arterial compliance, but not baroreflex function.
Abstract:
The objectives of this study were to determine whether carotid arterial compliance is reduced in patients with hypertension and to assess whether reduced arterial compliance is related to abnormal arterial baroreflex function. Accordingly, concurrent measurements of carotid arterial diameter (via computerized high resolution B-mode ultrasonography) and blood pressure were made to determine carotid arterial compliance in 23 normotensive and 16 age-matched hypertensive patients. In addition, arterial baroreflex function was assessed in 12 of the normal subjects and nine of the hypertensive patients by measuring the infusions of nitroprusside and phenylephrine. Compared with the normotensive subjects, the patients with hypertension had reduced compliance (5.9 +/- 0.7 vs. 16.6 +/- 1.8 10(-7) m2/kPa, mean +/- SE, P < 0.001). The baroreflex slope relating the change in R-R interval to the change in systolic blood pressure during the drug infusions was less in the hypertensive than normotensive subjects (12.3 +/- 2 vs. 18.9 +/- 2 ms/mmHg, P < 0.05). Consequently, when both normotensive and hypertensive subjects were considered, there was a significant correlation between the baroreflex slope and compliance (r = 0.53, P < 0.05). However, there was no correlation between the baroreflex slope and compliance within either the normotensive group (r = 0.04, P = NS) or the hypertensive group (r = 0.43, P = NS) when analyzed separately. There was a significant correlation between age and compliance (r = -0.48, P < 0.01) but not between age and baroreflex function.(ABSTRACT TRUNCATED AT 250 WORDS)