Cortisol excretion in essential hypertension.

A number of factors suggest that abnormalities of the adrenal cortex are present in essential hypertension. To determine whether altered cortisol excretion exists in essential hypertension, we have measured urinary free cortisol and cortisol to creatinine ratios in early morning urine specimens for 14 consecutive days. We have established a reference range for these parameters in 26 normotensive subjects. We have also compared these values in nine normotensive subjects and nine patients with essential hypertension closely matched for age, sex and body mass index. In the 26 normotensive subjects, urinary free cortisol was 240 +/- 13 nmol/l (mean +/- s.e.m) and cortisol to creatinine ratio was 22 +/- l. In the nine hypertensive subjects, urinary free cortisol was 238 +/- 48 nmol/l and cortisol to creatinine ratio was 20 +/- 3. We have not demonstrated an abnormality of cortisol excretion in essential hypertension.