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Glucocorticoids and hypertension in man
J A Whitworth1, J J Kelly, M A Brown
1Department of Medicine, St. George Hospital, University of New South Wales, Kogarah.
Summary
Cortisol can cause hypertension in men through mechanisms not fully understood. This study suggests increased renal vascular resistance is a key factor, independent of other hormonal changes or sodium retention.
Area of Science:
- Endocrinology
- Cardiovascular Physiology
- Nephrology
Background:
- Cortisol abnormalities are linked to hypertension in conditions like Cushing's syndrome and liquorice abuse.
- The precise mechanisms of cortisol-induced hypertension require further elucidation.
Purpose of the Study:
- To investigate the physiological mechanisms by which cortisol administration acutely raises blood pressure in healthy men.
- To identify the primary drivers of cortisol-induced hypertension.
Main Methods:
- Short-term administration of cortisol to normal male subjects.
- Monitoring of blood pressure, hormonal concentrations (vasopressors, vasodepressors), sympathetic activity, sodium balance, cardiac output, and renal vascular resistance.
Main Results:
- Cortisol administration induced hypertension without significant changes in vasopressor/vasodepressor hormones or sympathetic activity.
- Hypertension was associated with substantial sodium retention, but a sodium-independent component was also observed.
- An increase in cardiac output accompanied hypertension, though it was not essential for the blood pressure rise.
Conclusions:
- Cortisol-induced hypertension in men is not solely explained by altered vasopressor/vasodepressor systems or sympathetic activity.
- Increased renal vascular resistance is hypothesized as the primary mechanism driving cortisol-induced hypertension.
- Both sodium-dependent and sodium-independent factors contribute to cortisol-induced blood pressure elevation.