Greater change of orthostatic blood pressure is related to silent cerebral infarct and cardiac overload in hypertensive subjects.

Abstract

Greater change of postural blood pressure (BP) is often seen in elderly hypertensives and is recognized as a risk factor for cognitive decline and poorer cerebrovascular outcome, but its clinical significance still remains to be clarified. We performed a head-up tilting test, ambulatory BP monitoring, and brain MRI in 59 hypertensives and 27 normotensive subjects. We measured plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels at rest to assess cardiac burden. The 59 hypertensive patients were classified into 3 groups: an orthostatic hypertension (OHT) group with orthostatic increase in systolic BP (SBP) > or = 10 mmHg (n=16); an orthostatic hypotension (OHYPO) group with orthostatic SBP decrease < or = -10 mmHg (n=18); and an orthostatic normotension (ONT) group with neither of these two patterns (n=25). A group of 27 normotensive subjects (NT) was also included as a control. Plasma BNP (72 +/- 92 vs. 29 +/- 24 pg/ml, p < 0.05) and BNP/ANP ratio (4.6 +/- 3.3 vs. 2.4 +/- 1.5, p < 0.05) were significantly higher in the OHYPO than in the NT group. The BNP/ANP ratio was also higher in the OHT than in the NT group (5.1 +/- 3.9 vs. 2.4 +/- 1.5, p < 0.01). The number of silent cerebral infarct (SCI), prevalence of SCI and number of multiple SCIs was the highest in the OHT group, followed in order by the OHYPO, ONT and NT groups. Blood pressure and left ventricular mass index were not significantly different among the 3 hypertensive groups. In conclusion, hypertensive patients with greater change of postural BP (OHT and OHYPO) were shown to have increased risk of advanced silent brain lesions and greater cardiac burden.