Dexamethasone suppression in essential hypertension: effects on cortisol and blood pressure

Hypothalamic-pituitary-adrenal axis (HPA) function was examined in normotensive (n = 20) and hypertensive (n = 16) men, by measurement of basal cortisol levels, diurnal variation and the response to dexamethasone suppression. Comparison between groups did not reveal any differences in basal cortisol concentrations, in their diurnal variation, or in response to dexamethasone suppression. In separate studies, treatment with dexamethasone did not alter blood pressure in normal men (n = 6) but produced a small fall in pressure in hypertensive subjects (n = 8), compatible with the notion that the HPA might contribute to blood pressure elevation in some subjects with essential hypertension.