Browsing by Author "Barraza, A"

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    11 beta-hydroxysteroid dehydrogenase activity in patients with hypertension and low plasma renin activity
    (2002) Mosso, L; Carvajal, C; Campino, C; Rojas, A; Gonzalez, A; Barraza, A; Montero, J; Fardella, C; NCD Risk Factor Collaboration (NCD-RisC)
    Background: Half of hypertensive patients with, low plasma renin activity have a primary hyperaldosteronism. Among the remaining half 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2) deficiency plays all 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. Aim: To determine biochemical alterations, suggestive of 11betaSHSD2 deficiency, in low-renin hypertensive patients. Patients and Methods: Twenty eight hypertensive patients with a plasma renin activity of less than 0.5 ug/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 mug/dl, respectively; p <0.05). No differences were observed in serum cortisone (3.4 +/- 1.3 and 3.7 +/- 1.2 μg/dl, respectively). Four hypertensive subjects bad all 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 11.1βHSD2 deficiency.
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    Primary aldosteronism and hypertensive disease
    (2003) Mosso, L; Carvajal, C; Gonzalez, A; Barraza, A; Avila, F; Montero, J; Huete, A; Gederlini, A; Fardella, CE; NCD Risk Factor Collaboration (NCD-RisC)
    Recent studies in hypertensive populations that have used the serum aldosterone ( SA) to plasma renin activity (PRA) ratio as a screening test have demonstrated a high prevalence of primary aldosteronism (PA). This frequency is higher than that previously described when hypokalemia was used as a screening tool. However, other factors, such as the characteristics of hypertensive disease, could also influence the prevalence of PA. We studied 609 essential hypertensive patients, classified according to the Joint National Committee VI (JNC VI), in 3 different stages depending on the severity of their hypertensive disease. We measured SA and PRA and calculated the SA-PRA ratio for all patients. An SA-PRA ratio > 25 was detected in 63 of 609 patients, and the fludrocortisone test confirmed the PA diagnoses in 37 of 609 ( 6.1%) cases. PA prevalence according to hypertension stage was as follows: stage 1, 6 of 301 cases ( 1.99%); stage 2, 15 of 187 cases (8.02%); and stage 3, 16 of 121 cases (13.2%). PA patients were slightly younger than the other hypertensive patients ( 48.4 +/- 10.5 vs 53.6 +/- 10.2 years; P < 0.05). Serum potassium levels were normal in 36 of 37 PA patients; only 1 patient had minor hypokalemia. Computed tomography scans showed bilateral adrenal enlargement in 7 and an adrenal nodule in 2 cases. In summary, we found a high frequency of PA in essential hypertensives classified in stages 2 and 3 according to the JNC VI. The low frequency of computed tomography scan abnormalities and hypokalemia suggests that the diagnosis for most PA patients corresponds to attenuated forms of the disease.