Key Points
- To examine whether changes in central blood volume induced by different postures influence brain natriuretic peptide secretion in healthy subjects and patients with essential hypertension.
- Evaluated 11 healthy subjects and 20 patients with essential hypertension after 15 minutes supine, 15 minutes sitting, and 15 minutes with legs elevated at 60°.
- Measured plasma human brain natriuretic peptide-32-like immunoreactivity (hBNP-32-li) via radioimmunoassay alongside atrial natriuretic peptide, plasma renin activity, and aldosterone levels.
- Baseline supine hBNP-32-li levels were significantly higher in hypertensive patients (2.39 ± 0.13 fmol/ml) than in healthy subjects (1.57 ± 0.10 fmol/ml, P < 0.001).
- Sitting significantly decreased hBNP-32-li levels in both normotensive (1.22 ± 0.08 fmol/ml) and hypertensive subjects (1.85 ± 0.15 fmol/ml, P < 0.001), whereas leg elevation increased levels to 2.13 ± 0.12 fmol/ml (P < 0.002) and 2.84 ± 0.16 fmol/ml (P < 0.001), respectively.
- Plasma hBNP-32-li across all postures correlated positively with atrial natriuretic peptide (normotensive: r = 0.55; hypertensive: r = 0.69; both P < 0.001) and negatively with plasma renin activity (r = -0.56 and r = -0.58; both P < 0.001).
Structured PICO
Do posture-induced changes affect plasma levels of brain natriuretic peptide in healthy subjects and patients with essential hypertension?
PPopulation31 subjects, comprising 11 healthy subjects and 20 patients with essential hypertension
IInterventionPostural changes (15 min supine, 15 min sitting, and 15 min with legs raised at 60°)
CComparatorComparison between different postural positions and between healthy subjects versus hypertensive patients
OOutcomePlasma levels of human brain natriuretic peptide-32-like immunoreactivity (hBNP-32-li)surrogate
Postural changes significantly affect plasma BNP levels in both healthy individuals and hypertensive patients, with hypertensive patients maintaining higher baseline and stimulated levels.