Background
Knowledge of hemodynamic factors accounting for the development of hypertension should help to tailor therapeutic approaches and improves blood pressure control. Few data exist regarding sex differences of hemodynamic factors contributing to hypertension progression among untreated non-diabetic prehypertensive (PreHyp), Stage I and II subjects as define by the Joint National Commission-7 guidelines (JNC-7).
Methods
We utilized non-invasive impedance cardiography, applanation tonometry, and plasma measures of angiotensin II, angiotensin-(1-7), serum aldosterone, hs-C reactive protein, and cytokine biomarkers of inflammation to characterize the hemodynamic and hormonal profile of 100 untreated hypertensive subjects (39 females).
Results
Despite there being no differences between females and males in terms of office blood pressure, heart rate, and body mass index, males demonstrated lower values of pulse pressure, systemic vascular resistance, brachial artery pulse wave velocity, and augmentation index. In each of the three hypertension categories, the increased blood pressure in males was associated with significant augmentations in stroke volume and cardiac output when compared to females. Sex related hemodynamic differences were associated in females with higher plasma levels of leptin, hs-C-reactive protein, plasma angiotensin II, and serum aldosterone and no differences in the serum concentrations of cytokinins. In women but not men, hs-C reactive protein correlated with plasma concentrations of TGF-β1 and body weight, in addition, plasma TGF-β1 correlated with levels of serum VCAM-1.
Conclusions
The impact of sex differences in the hemodynamic factors accounting for the elevation in arterial pressure in essential hypertensive subjects has been poorly characterized or this information is not available. We suggest that this gap in knowledge may adversely influence choices of drug-treatment since our study shows for the first time significant differences in the hemodynamic and hormonal mechanisms accounting for the increased blood pressure in women compared to men.