Does orthostatic hypotension predict the occurrence of nocturnal arterial hypertension in the elderly patient?

OBJECTIVE

To determine whether the presence of orthostatic hypotension--which, in this age-group, could be due to varying degrees of autonomic dysfunction--is an indicator of nocturnal arterial hypertension.

PATIENTS

Between 1999 and 2001 we prospectively and consecutively studied 93 elderly patients with untreated (office) arterial hypertension, 65 (70%) of whom were true hypertensives according to 24 h ambulatory blood pressure monitoring (ABPM).

INTERVENTIONS

The patients were studied by clinical examination including blood pressure (BP) measurement in dorsal decubitus and orthostatic position, 24 h ABPM, evaluation of vascular distensibility by carotid-femoral pulse wave velocity (PWV) and Doppler echocardiography. For this study we analyzed especially the ambulatory behavior of BP, so we could relate the variation of systolic blood pressure (SBP) during orthostatism with non-dipper status for SBP and absolute nocturnal values of SBP.

MEASUREMENTS AND RESULTS

The results indicated that a greater decrease of blood pressure with orthostatism corresponded to a greater probability of nocturnal hypertension (p = 0.005) and of non-dipper status (p = 0.02). These results are in agreement with those subsequently found by other authors (Kario et al., 2002).

CONCLUSIONS

In this way, by means of a simple clinical maneuver that should always be performed in an elderly hypertensive patient, we can suspect the presence of nocturnal hypertension--which is a high-risk cardiovascular situation--and use this information to help select patients to undergo 24 hour-ABPM.