Actividad de 11 beta hidroxiesteroide dehidrogenasa tipo 2 en hipertensos chilenos / 11 B-hydroxysteroid dehydrogenase activity in patients with hypertension and low plasma renin activity

Background: Half of hypertensive patients with low plasma renin activity have a primary hyperaldosteronism. Among the remaining half, 11ß-hydroxysteroid dehydrogenase type 2 (11ßHSD2) 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. Aim: To determine biochemical alterations, suggestive of 11ßHSD2 deficiency, in low-renin hypertensive patients. Patients and 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 (11.1ñ3.3 and 9.2ñ2.8 µg/dl, respectively; p <0.05). No differences were observed in serum cortisone (3.4ñ1.3 and 3.7ñ1.2 µg/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 11ßHSD2 deficiency

Alta prevalencia de enfermedad tiroidea subclínica en sujetos que concurren a control de salud / High prevalence of subclinical thyroidal disease among individuals attended in occupational health examinations

Background: There is no information about the prevalence of thyroidal diseases in the general Chilean population. Aim: To assess the prevalence of thyroidal diseases in individuals attended in occupational health examinations. Subjects and methods : Four hundred seventy two individuals were examined between 1998 and 1999. In all, serum levels of thyroid hormones, TSH and anti thyroidal antibodies (anti microsomal, anti thyroid peroxidase and anti thyroglobulin) were measured. Results: Forty four subjects were excluded from the study due to an incomplete medical record and 18 due to a personal history of thyroidal disease. Abnormal serum levels of thyroid hormones or TSH were detected in 28 subjects (6.8 percent). Four (1 percent) had hypothyroidism, 23 a subclinical hypothyroidism (5.6 percent) and one (0.2 percent) had hyperthyroidism. In 87 subjects (21.2 percent) at least one of the antibodies was positive. Positive anti thyroid antibodies were found in 14 of 28 subjects (50 percent) with abnormal thyroid hormone levels, compared with 73 of 382 subjects (19.1 percent) with normal thyroid hormone levels. Thyroid dysfunction was twice as frequent in women than in men. Conclusions: In this sample, a 6.8 percent prevalence of abnormal thyroid function tests was detected

Efecto de dosis bajas de calcitonina sobre la remodelación ósea en mujeres postmenopáusicas con alto recambio / Effects of low calcitonin doses on bone remodeling in postmenopausal women with high bone turnover rate

Background: Calcitonin is specially indicated for the treatment of osteoporosis in women that cannot receive estrogen replacement therapy or that have a high bone turnover rate. Aim: To study the effects of low intranasal calcitonin doses on bone remodeling in postmenopausal women with a high bone turnover. Patients and methods: Forty one healthy women aged 56 ñ 6 years old, with a mean lapse after menopause of 7.6 ñ 6.5 years and with a high bone turnover rate, evidenced by an urinary hydroxyproline (mg/dl)/creatinine (g/dl) ratio of 52.4 ñ 7.2, were studied. They were randomly assigned to receive 100 or 50 U/calcitonin thrice a week during 3 months or to a control group that received placebo. All received 500 mg/day calcium carbonate. Urinary hydroxyproline/creatinine ratio was measured a 0, 15, 30, 60 and 90 days. Plasma bone fraction of alkanine phosphatases was measured at 0, 30 and 90 days. Results: Initial urinary hydroxyproline/creatinine ratio and plasma bone fraction of alkanine phosphatases were similar in all study groups and there was no change in these parameters during the study period. Conclusions: Intranasal calcitonin in doses of 100 U thrice a week or less, does not modify accelerated bone turnover in postmenopausal women

Alta prevalencia de hiperaldosteronismo primario no diagnosticado en hipertensos catalogados como esenciales / High prevalence of undiagnosed primary hyperaldosteronism among patients with essential hypertension

Background: Classically, primary hyperaldosteronism was diagnosed in no more than 1 percent of patients with hypertension, when hypokalemia was used as the screening test. However, numerous patients with primary hyperaldosteronism do not have hypokalemia and the disease remains undiagnosed. Aim: To assess the prevalence of normokalemic primary hyperaldosteronism among patients classified as having essential hypertension. Patients and methods: One hundred hypertensive patients with a blood pressure over 145/95 were studied. Plasma aldosterone and plasma renin activity were measured in all. A primary hyperaldosteronism was diagnosed when high aldosterone levels (over 16 ng/dl) and low plasma renin activity (below 0.5 ng/ml/h) coexisted in two blood tests or the aldosterone/plasma renin activity ratio was over 50. A probable primary hyperaldosteronism was diagnosed when the ratio was between 25 and 50 and these patients were subjected to a Fludrocortisone test to confirm the diagnosis. A dexametasone suppression test was done to discard glucocorticoid remediable aldosteronism. An adrenal TAC scan was done to all patients with primary hyperaldosteronism. Results: A diagnosis of primary hyperaldosteronism was reached in ten patients. Seven had elevated aldosterone and low plasma renin activity. In three the diagnosis was confirmed with the fludrocortisone test. All ten patients had normal serum potassium levels. Dexametasone suppression test was positive in three patients, that normalized their blood pressure levels. Adrenal TAC scans showed an adenoma in one patient and hyperplasia in another. Conclusions: Primary hyperaldosteronism is more frequent than previously thought, it is overlooked when hypokalemia is used as the screening test and it can only be diagnosed measuring plasma aldosterone and renin activity

Comparación de la acción antioxidante de estriol y estradiol in vitro sobre lipoproteínas de baja densidad en mujeres postmenopáusicas / Comparison of antioxidant actions of estriol and estradiol on low density lipoproteins in post menopausal women

Background: Estradiol (E2) has a potent antioxidant effect on low density lipoproteins (LDL) in vitro and in vivo, which could be important in explaining the cardioprotective effect of hormone replacement therapy (HRT) in post menopausal women. Estriol (E3), on the other hand, is a weak estrogen with low metabolic effects on different tissues, and at present no cardioprotective effect has been attributed to this steroid. Aim: To study the antioxidant effect of E3 on LDL and to compare it with the potent antioxidant action exhibited by E2. Subjects and methods: After LDL was isolated by ultra centrifugation from plasma of 12 healthy untreated post menopausal women, it was divided into aliquots containing 0.5 mg of LDL protein. Estriol and E2 in doses of 0, 1, 5, 15 and 50 µM were incubated with different aliquots of LDL. CuSO4 15 µM was added to each aliquot to induce an oxidative stress. The aliquots were then incubated during 4 hours at 37 ­C. Malonaldehyde (MDA) was measured as a marker of LDL oxidation, and expressed as nM/mg protein. Results (mean ñ SD): Estriol induced a dose-dependent decrease in MDA concentration (baseline 62.8 ñ 21.7; 1 µM: 61.5 ñ 23.0; 5 µM: 52.9 ñ 20,3; 15 µM 43.5 ñ 20.1 and 50 µM: 31.0 ñ 17.6 nM/mg protein; F= 92.4; p< 0.0001), reaching a mean decrease of 50.7 percent at the highest dose tested. Estradiol has a similar dose-dependent decrease in MDA concentration (F= 60.2; p< 0.0001), revealing a more potent effect than E3 (p< 0.05), with a mean decrease of 67.4 percent at the highest dose tested. Conclusions: Our results demonstrate that estriol shows an important antioxidant action of LDL in vitro, although its effect is less potent than estradiol. These results raise the possibility that estriol could have a cardioprotective effect in post menopausal women, possibility that has not been yet demonstrated

Modificación de la reabsorción ósea con terapia hormonal de reemplazo en la postmenopausia / Modification of bone resorption with replacement hormonal therapy in postmenopause

Eighty three postmenopausal women without replacement hormonal therapy, 54 postmenopausal women receiving replacement hormonal therapy and 16 premenopausal women (considered as control group) were studied. Hydroxyproline was measured in an early morning urine sample, after one day of diet without meat or gelatin. Urinary hydroxyproline in premenopausal women was 33.7ñ7.9 mg/g creatinine. The figure for postmenopausal women with hormonal replacement therapy was 33.5ñ7.9 mg/g creatinine. Postmenopausal women without replacement therapy had an urinary hydroxyproline of 47.4ñ8.5 mg/g creatinine, significantly higher than that of premenopausal and supplemented women. In 21 postmenopausal women, hydroxyproline was measured before and after 3 months of replacement therapy; values decreased 35.5ñ11 percent in this period and there was a direct correlation between initial values and the degree of reduction (r=0.69, p<0.001). Postmenopausal women receiving hormone replacement therapy have a urinary hydroxyproline excretion similar to that of premenopausal women

Velocidad de disolución de diferentes preparados de calcio utilizados en clínica / Dissolution velocity of different calcium solutions used in clinics

Hydrochloric acid was added to destilled water in increasing amounts to obtain a final pH of 6.9, 3.0, 2.5, 2.0 and 1.5. Eighteen commercial calcium preparations were incubated in these solutions for 60 min and dissolution velocity was measured as the percentage of elemental calcium found in solution after this incubation period. Calcium carbonate preparations had a pH 1.5. Using the solution with pH 1.5 the dissolution velocity of different preparations varied widely from 56 to 100 percent. Calcium acetate, followed by calcium citrate and dicalcic phosphate were the salts in tablets with better dissolution velocities. Among powders and effervescent preparations, those containing calcium lactogluconate and citrate had the better dissolution velocities (95 to 115 percent), that were independent of the solution's pH. A studied preparation with integral bone had a very low dissolution velocity, not surpassing 33 mg of calcium per tablet. The dissolution velocity of different calcium carbonate preparations varies greatly and in conditions of achlorhydria, it is negligible. Calcium lactogluconate and citrate dissolution velocities are independent of the solution's pH

Importancia del déficit de inhibidores de la cristalización en la etiopatogenia de la urolitiasis / Importance of crystallization inhibitors deficit in the etiopathogenic of urolithiasis

Background: five percent of consultations at the emergency room of Catholic University Hospital are due to nephrolithiasis. The causes of this high frequency remain unknown. Aim: to know the main metabolic and anatomic factors involved in the genesis of nephrolithiasis. Patients and methods: 41 patients (31 male) were studied presenting with a renal colic were studied as soon as the acute episode subsided and without diet modifications. Fasting blood calcium and creatinine and 24 h urine calcium, uric acid, citrate, magnesium and pH were measured and an intravenous pyelogram was performed. 21 subjects without a history of nephrolithiasis were used as controls. Results: Patients with nephrolithiasis did not differ from controls in urinary calcium (159 ñ 67 and 172 ñ 67 mg/24 h respectively), uricosuria (417 ñ 171 and 431 ñ 121 mg/24 h respectively) or urinary magnesium (55 ñ 19 and 62 ñ 21 mg/24 h respectively, whereas urinary citrate was lower (219 ñ 172 vs 319 ñ 179 mg/24 h in controls p <0.05). All patients had a normal renal functions, urinary acidification and intravenous pyelogram. Seven percent of patients with nephrolithiasis had hypercalciuria, 2.4 percent had hyperuricosuria, 68.3 percent had a low urinary citrate and 44.4 percent had low urinary magnesium. Conclusions: in this sample, there is a strong association of nephrolithiasis with low levels of crystallization inhibitors in special with urinary citrate, a crystallization inhibitor

Síndrome de ovario poliquístico como expresión de déficit de la enzima 3ß hidroxiesteroide deshidrogenasa / Polycystic ovary syndrome as expression of 3-beta-hydroxysteroid dehydrogenase deficit

Los defectos enzimáticos de expresión tardía de la esteroidogénesis suprarrenal están entre las causas más comunes de hirsutismo. Esta forma de hiperandrogenismo puede asumir las características clínicas de un síndrome de ovario poliquístico, lo que viene a confirmar la multicausalidad de esta última condición. Se comunica el caso de una mujer de 18 años con amenorrea secundaria e hirsutismo, cuya concentración sérica de testosterona y de DHEA-S eran 175 ng/dl y 7,3 *g/ml respectivamente y la relación LH/FSH de 5,9. La administración de dexametasona produjo una marcada reducción en la concentración de testosterona y DHEA-S, en tanto que el estímulo con ACTH se asoció a un aumento de 17 hidroxipregnenolona y de la relación 17 hidroxipregnenolona/17 hidroxiprogesterona en el rango descrito para el déficit de 3ß hidroxiesteroide deshidrogenasa

Hiperplasia suprarrenal de expresión tardía: optimización de la terapia midiendo la variación circadiana de la 17-OH-progesterona sérica / Late onset adrenal hyperplasia: optimization of treatment by assesment of the circadian variation in serum 17-OH-progesterone

A 19 yr-old female patient with the diagnosis of late onset adrenal hyperplasia was treated since age 15 with different glucocorticoid preparations and dosage schedules plus spsironulactone. In spite of a very tgood response in terms of amelioration of ther hursutism she experienced cushingoid manifestations associated with, adrenal suppression. To overcome these side effects the patient was placed ons hydrocortisone 20 mg at 8 AM plus spironallactone 50 mg q.i.d. Cushingoid features vanished and response to cosyntropin (ACTH 250 ug i.m.) was reestablished. To better ascertain the effects of this administered at 8 AM and compared it with curcadian variations under basal conditions or after late-evening (11 PM) adminsitration of hydrocortisosne, 20 mg. The early morning adminstration of hydro cortisone was unable to prevent the nocturnal elevation of 17-OH-progesterone in spite of normal levels from 9.30 AM to 3 AM. This nocturnal peak was associated with a slightly blunted nocturnal elevation of serum cortisol. In contrast, the late evening adminsitration of hidrocortisone was able to supress 17-OH-progesterone to within normal levels during all day. Serum cortisol during late evening therapy was not different from that observed during early morning adminstration (12.2 ñ 13.1 vs 9.9 ñ 11.3 ug/dl,p = 0.53), yet the corresponding 17-OH-progesterone levels were much lower (0.8 ñ 0.6 vs 5.9 ñ 6.9 ng/ml. We conclude that individualization of therapy is essential in patients with lateosnt adrenal