[11 beta-hydroxysteroid dehydrogenase type 2 activity in Chilean patients with hypertension].
BACKGROUND
Half of hypertensive patients with low plasma renin activity have a primary hyperaldosteronism. Among the remaining half, 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta HSD2) deficiency plays an important role. This enzyme catalyzes the conversion of cortisol to cortisone, avoiding the interaction of cortisol with the mineralocorticoid receptor. If the enzyme fails, cortisol will stimulate sodium and water reabsorption and increase blood pressure.


OBJECTIVE
To determine biochemical alterations, suggestive of 11 beta HSD2 deficiency, in low-renin hypertensive patients.


METHODS
Twenty eight hypertensive patients with a plasma renin activity of less than 0.5 ng/ml/h and with a plasma aldosterone of less than 5 ng/dl were studied. Twenty eight normotensive patients were studied as controls. Serum cortisol (RIA), cortisone (ELISA) and the serum cortisol/cortisone ratio were determined in all of them, between 9 and 10 AM. Measurements were confirmed by high pressure liquid chromatography. The serum cortisol/cortisone ratio was considered abnormal when its Ln (cortisol/cortisone) value was over 2 standard deviations of the mean.


RESULTS
Serum cortisol was higher in hypertensive subjects than in controls (11.1 +/- 3.3 and 9.2 +/- 2.8 micrograms/dl, respectively; p < 0.05). No differences were observed in serum cortisone (3.4 +/- 1.3 and 3.7 +/- 1.2 micrograms/dl, respectively). Four hypertensive subjects had an abnormally high Ln (cortisol/cortisone) value (1.86; 1.73; 2.07 and 2.01, considering a normal value of less than 1.61).


CONCLUSIONS
Four of 28 hypertensive subjects with low plasma renin activity and aldosterone had biochemical alterations suggestive of 11 beta HSD2 deficiency.
Mosso
Lorena
L
Departamentos de Endocrinología y Medicina Interna, Centro de Investigaciones Médicas, Escuela de Medicina, Pontificia Universidad Católica de Chile.
Carvajal
Cristian
C
Campino
Carmen
C
Rojas
Auristela
A
González
Alexis
A
Barraza
Adolfo
A
Montero
Joaquín
J
Fardella
Carlos
C
D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; D000450:Aldosterone / Q000097:blood*; D016022:Case-Control Studies; D002677:Chile; D002851:Chromatography, High Pressure Liquid; D003348:Cortisone / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006913:Hydroxysteroid Dehydrogenases / Q000172:deficiency*; D006973:Hypertension / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012083:Renin / Q000097:blood*
D000450:Aldosterone; D006913:Hydroxysteroid Dehydrogenases; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; C468387:HSD11B2 protein, human; D012083:Renin; D003348:Cortisone; D006854:Hydrocortisone