APPARENT MINERALOCORTICOID EXCESS TYPE-II

The syndrome of apparent mineralocorticoid excess (AME) is currently u nderstood to reflect impaired peripheral metabolism of cortisol, which is then able to activate the non-selective mineralocorticoid (MC) rec eptor. The failure of glucocorticoid inactivation at the MC target tis sue level in AME involves abnormal activity of 11 beta-hydroxysteroid dehydrogenase, with impaired conversion of cortisol to cortisone, and also of 5 beta-reductase. We have discovered a new form of AME (Type I I) in four patients with the same clinical picture of hypertension, hy pokalemia, and suppressed renin-angiotensin-aldosterone system, but in whom this conversion seems either to be normal (since cortisol to cor tisone metabolite ratio is normal) or to be impaired in both direction s, leaving the ratio unchanged. Both types are characterized by a prof ound decrease in cortisol turnover quotient and Ring A reduction const ant. Short-term dexamethasone treatment is effective in correcting the MC-derived abnormalities, while in the long term the addition of othe r antihypertensive drugs may be required to control the severity of hy pertension.