Association of decreased plasma cortisol and corticosteroid-binding globulin binding capacity in patients with essential hypertension and their first degree relatives.

Both plasma cortisol and total corticosteroid-binding globulin (CBG) binding capacity were lower in 210 patients with uncomplicated essential hypertension (EH) and their 66 hypertensive first degree relatives, compared with 171 controls. However, both variables were similar in 84 normotensive relatives to those found in control subjects showing extensive variation over the entire control-EH range. The association of reduced plasma cortisol and CBG binding capacity in EH may be closely related to altered steroid metabolism which may be partly explained by an abnormality mimicking a relative deficiency in adrenal 17 alpha- and 11 beta-hydroxylation. One manifestation of this disorder in EH is an increase in the secretion rate and plasma levels of dehydroepiandrosterone sulphate (DHEA-S) which is bound with high-affinity to a low-capacity specific plasma globulin and accounts for most of the digitalis-like activity of human plasma.