PLASMA BRAIN NATRIURETIC PEPTIDE AND C-TYPE NATRIURETIC PEPTIDE IN ESSENTIAL-HYPERTENSION

Objectives: To study the relationship between hypertension and the pla sma levels of brain natriuretic peptide (BNP) and C-type natriuretic p eptide (CNP), and to determine whether the plasma levels of BNP and CN P are correlated. Design: A cross-sectional study of the plasma levels of BNP and CNP in hypertensive patients and normotensive controls mat ched for age and sex was performed. Setting: The hypertension research clinic in a teaching hospital and well-person risk factor screening c linics in general practice health centres. Participants: Fifty-four su bjects (29 hypertensive, 25 normotensive controls) took part in the st udy after giving their informed consent. Hypertensive patients (n = 19 ) were paired with normotensive controls (n = 19) matched for age and sex to form a subgroup before analysis of the plasma. Methods: The pla sma levels of BNP and CNP were determined by specific radioimmunoassay s. Results: The mean plasma concentration of BNP was significantly hig her in the hypertensive group than in the paired controls. in contrast , the mean plasma concentration of CNP was not significantly different in the hypertensive group than in the paired controls. Multiple regre ssion analysis of all 54 subjects showed that the plasma level of BNP correlated significantly with age and systolic blood pressure, whereas the plasma level of CNP correlated significantly with sex, heart rate and alcohol intake. The CNP levels did not correlate significantly wi th either systolic or diastolic blood pressure, or with plasma brain n atriuretic levels. Conclusions: Hypertension is associated with raised BNP but not CNP plasma levels.