Cortisol metabolism in hypertensive patients who do and do not develop hypokalemia from diuretics

Deficiency of 11 beta-hydroxysteroid dehydrogenase causes hypertension and hypokalemia. To test whether hypertensive patients who develop hypokalemia when treated with diuretics have low levels of activity of this enzyme as a metabolic predisposition to the development of hypokalemia, we measured urinary cortisone, cortisol, tetrahydrocortisol, tetrahydrocortisone, and creatinine in 42 hypertensive patients who either did or did not become hypokalemic on hydrochlorothiazide. The mean ratios of cortisone to cortisol, tetrahydrocortisone to tetrahydrocortisol, tetrahydrocortisol to cortisol, and cortisol to creatinine did not differ between the two groups. We conclude that hypertensives who develop hypokalemia on diuretics do not have low activity of this enzyme. They also do not appear to have low ring A reduction or higher cortisol secretion rates compared with hypertensives who do not develop hypokalemia. We failed to find a metabolic predisposition to the development of hypokalemia by diuretic treatment.