Lack of regional and whole body sympathetic normalization during antihypertensive drug treatment: a potential link for the residual risk

Introduction: It is unknown whether the failure of antihypertensive drug treatment to normalize sympathetic cardiovascular (CV) function reported in previous studies selectively affects regional sympathetic CV outflow or it also involves whole body neuroadrenergic drive. Aim: The present study examines the impact of antihypertensive drug treatment on regional and whole body sympathetic CV influences. Methods: Fifthyfour essential hypertensive patients were included in the study. In each patient measurements consisted of the microneurographic recording of muscle sympathetic nerve traffic (MSNA) and the assay of venous plasma norepinephrine (NE). They were performed before and during an antihypertensive drug treatment (monotherapy or two-drugs combination) prolonged for a 3 months period. Measurements were also carried out in 31 age-matched normotensive controls. Results: In the study population antihypertensive drug treatment lowered clinic blood pressure to values <140/90 mmHg and significantly (P<0.001) reduced both MSNA and NE. However, during treatment the values of these two adrenergic markers remained significantly greater (+70.8 % and +64.4%, respectively) than those detected in the normotensive subjects. Conclusions: These data provide evidence that antihypertensive drug treatment reduces but not normalizes regional and whole body sympathetic CV drive, likely participating at determining the residual CV risk reported in different studies in treated hypertensives.