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Gender-specific cardiovascular adaptation due to circadian blood pressure variations in essential hypertension
R E Schmieder1, J K Rockstroh, F Aepfelbacher
1Department of Medicine IV, University of Erlangen-Nuremberg, Nuremberg, Germany.
Insights
Circadian blood pressure patterns impact heart health differently in men and women. Nondipping blood pressure in women, but not men, is linked to increased left ventricular hypertrophy, suggesting sex-specific cardiovascular risks.
Area of Science:
- Cardiology
- Hypertension Research
- Chronobiology
Background:
- Essential hypertension affects millions globally.
- Circadian variations in arterial pressure are linked to target organ damage.
- Understanding sex differences in hypertension's effects is crucial.
Purpose of the Study:
- To investigate the impact of circadian arterial pressure variations on early hypertensive target organ disease.
- To compare effects between genders in patients with untreated essential hypertension.
Main Methods:
- Assessed systemic and renal hemodynamics, left ventricular structure/function, and 24-h ambulatory blood pressure.
- Categorized participants into 'dippers' and 'nondippers' based on nocturnal blood pressure decrease.
- Utilized indocyanine green dye dilution, iodine-131 para-aminohippuric acid clearance, and echocardiography.
Main Results:
- Female nondippers showed significantly higher left ventricular mass, mass index, relative wall thickness, and posterior wall thickness compared to female dippers.
- No significant differences in left ventricular structure were observed between male dippers and nondippers.
- Systemic/renal hemodynamics, neurohormonal factors, and causal blood pressure did not differ between dipper/nondipper groups.
Conclusions:
- Left ventricular hypertrophy correlates with circadian blood pressure variations in women but not men.
- Left ventricular structure may be more susceptible to blood pressure load in women with essential hypertension.
- Highlights potential sex-specific mechanisms in hypertensive heart disease progression.
Abstract:
To determine the effects of circadian variation in arterial pressure on early hypertensive target organ disease, we examined systemic hemodynamics (cardiac output by indocyanine green dye dilution), renal hemodynamics (renal plasma flow by iodine-131 para-aminohippuric acid clearance), left ventricular structure and function (2D-guided M-mode echocardiogram), and 24-h ambulatory blood pressure in 20 women and 46 men with untreated essential hypertension. Both gender groups were subdivided into "dippers" and "nondippers" according to the physiologic nocturnal decrease in mean arterial pressure by 10% of daytime values. Systemic and renal hemodynamics, neurohumoral findings (norepinephrine, epinephrine, dopamine, plasma renin activity), causal blood pressure values, duration of hypertension, and body weight did not differ between the two groups. In contrast, left ventricular mass and mass index was higher in female nondippers than dippers (255 +/- 68 v 184 +/- 81 g, and 137 +/- 30 v 102 +/- 39 g/m2, P < .05, respectively), while in men no significant differences were found (234 +/- 48 v 240 +/- 54 g, and 119 +/- 27 v 121 +/- 13 g/m2, P = NS, respectively). Relative wall thickness (0.45 +/- 0.06 v 0.39 +/- 0.06, P < .05) and posterior wall thickness (1.1 +/- 0.1 v 0.89 +/- 0.2 mm, P < .05) were also found to be greater in female nondippers than in dippers, whereas no significant differences were obtained in men. Thus, the degree of left ventricular hypertrophy correlated with the circadian blood pressure variations in women only, which indicates that left ventricular structure may be more load-dependent in women than in men with essential hypertension.