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1.
Kidney Int ; 73(6): 679-83, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18160962

RESUMEN

Aliskiren represents the first member in a new class of antihypertensive drugs. Inhibiting the renin-angiotensin system at its rate-limiting step is an idea that has been pursued for >30 years; however, earlier compounds failed because of problems related to efficacy, bioavailability, and/or side effects. Aliskiren, a 610 Da nonpeptide molecule, has exceptional affinity for the human renin enzymatic site and a half-life of about 40 h, which make its 3% bioavailability clinically unimportant with continued administration. The drug is not metabolized by CYP P450 enzymes and is excreted >90% unchanged by the fecal route. No adjustments are necessary for renal function, liver function, age, ethnicity, or other prescribed drugs. Blood pressure reductions are similar to those provided by other monotherapies. Interestingly, aliskiren combined with angiotensin receptor blocker or angiotensin-converting enzyme inhibitor therapy leads to a further blood pressure reduction as does combination with a diuretic or calcium channel blocker. The fact that plasma renin activity is reduced to low levels with aliskiren could provide a theoretical advantage over other treatments, while increases in total renin (prorenin) after the drug poses additional food for thought. Studies with primary cardiovascular and renal end points to address these possibilities are in progress.


Asunto(s)
Amidas/uso terapéutico , Antihipertensivos/uso terapéutico , Fumaratos/uso terapéutico , Sistema Renina-Angiotensina/efectos de los fármacos , Amidas/química , Amidas/farmacología , Antihipertensivos/química , Antihipertensivos/farmacología , Presión Sanguínea/efectos de los fármacos , Enfermedades Cardiovasculares/tratamiento farmacológico , Fumaratos/química , Fumaratos/farmacología , Humanos , Fallo Renal Crónico/tratamiento farmacológico
2.
J Clin Invest ; 52(9): 2272-7, 1973 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-4353776

RESUMEN

Plasma aldosterone, cortisol, and renin activity were measured in nine recumbent patients with hyperaldosteronism, including seven with adenomas, one with idiopathic hyperplasia, and one with glucocorticoid suppressible hyperplasia. All had peak values of plasma aldosterone concentration from 3 a.m. to noon and lowest values at 6 p.m. or midnight. This rhythm was similar to the circadian pattern of plasma cortisol in the same patients. When these data were normalized to eliminate the wide variation in ranges of plasma aldosterone and cortisol between individuals, there was an excellent correlation (r = + 0.87, P < 0.005) between the two hormones. In contrast, plasma aldosterone concentrations did not correlate with plasma renin activity before or after normalization of data. Short term suppression of ACTH by administration of dexamethasone eliminated the circadian variation of plasma aldosterone in both patients with hyperplasia and in four of five patients with adenomas, while it markedly altered the rhythm in the fifth. Similar doses of dexamethasone were administered to four normal subjects and did not flatten the circadian rhythm of plasma aldosterone. These data suggest that patients with primary aldosteronism have a circadian rhythm of plasma aldosterone mediated by changes in ACTH.


Asunto(s)
Aldosterona/sangre , Ritmo Circadiano , Hiperaldosteronismo/fisiopatología , Adenoma/complicaciones , Neoplasias de las Glándulas Suprarrenales/complicaciones , Hiperfunción de las Glándulas Suprarrenales/complicaciones , Hormona Adrenocorticotrópica/antagonistas & inhibidores , Dexametasona/farmacología , Humanos , Hidrocortisona/sangre , Hiperaldosteronismo/etiología , Potasio/sangre , Renina/sangre
3.
J Clin Invest ; 49(7): 1415-26, 1970 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-4317384

RESUMEN

Among 25 patients with benign, essential hypertension, and an equal number with other benign forms of hypertension, without serious cardiac, renal, or cerebrovascular impairment, 41 cases failed to reduce aldosterone excretion rates into the normal range (less than 5 mug/day) on a daily intake of 300 mEq of sodium. The hypertensive patients excreted slightly less than the normal fraction of labeled aldosterone as acid-hydrolyzable conjugate. Secretion rates were significantly higher in the hypertensive patients than in normotensive controls taking the high-sodium intake. On a 10 mEq sodium intake, the increase in excretion and secretion rates of aldosterone in the hypertensive patients could be correlated with plasma renin activity (PRA). The patients with the least increase in PRA had subnormal increase in aldosterone secretion and excretion, while unusually large rises in aldosterone secretion accompanied high PRA, especially in the cases with increased plasma angiotensinogen induced by oral contraceptives. The persistence of inappropriately high aldosterone secretion in most hypertensive patients during sodium loading could be related to a higher PRA than that found in normotensive controls under comparable conditions. In other hypertensives, whose PRA was unresponsive to sodium depletion, there was no significant correlation between PRA and aldosterone output, and no known stimulus to aldosterone production was detected. Five obvious cases of hyperaldosteronism were found among the 16 low-renin patients. The cause of the nonsuppressible aldosterone production in the other low-renin cases remains to be determined.


Asunto(s)
Aldosterona/metabolismo , Hipertensión/metabolismo , Renina/sangre , Sodio/metabolismo , Adolescente , Hiperfunción de las Glándulas Suprarrenales/orina , Adulto , Aldosterona/orina , Angiotensina II/sangre , Anticonceptivos Orales/farmacología , Humanos , Hiperaldosteronismo/orina , Hipertensión/sangre , Hipertensión/orina , Potasio/sangre , Obstrucción de la Arteria Renal/orina
4.
Arch Intern Med ; 145(6): 1102-5, 1985 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2860883

RESUMEN

Elevations in the levels of total serum cholesterol, triglycerides, and low-density lipoproteins increase the risk of coronary artery disease and atherogenesis. High-density lipoproteins (HDLs) are beneficial in removing lipid from tissues. High-risk men adhering to a diet and/or receiving cholestyramine to lower their elevated lipid levels had lowering of cardiac mortality. Hypertension is also a major risk factor for cardiovascular disease and for accelerated atherosclerosis. The benefit of blood pressure reduction may not be consistent in decreasing cardiovascular morbidity and mortality among all mildly hypertensive persons. Many antihypertensive agents may raise undesirable lipid fractions and/or lower HDL levels, enhancing the risk of cardiovascular disease, while others have few negative effects. Thus, the antihypertensive agent chosen may modify lipid levels and cardiovascular risk in hypertensive patients.


Asunto(s)
Antihipertensivos/uso terapéutico , Enfermedad Coronaria/prevención & control , Grasas de la Dieta/metabolismo , Hipertensión/tratamiento farmacológico , Metabolismo de los Lípidos , Antagonistas Adrenérgicos beta/uso terapéutico , Colesterol/sangre , Enfermedad Coronaria/etiología , Diuréticos/uso terapéutico , Humanos , Hipertensión/sangre , Hipertensión/complicaciones , Lipoproteínas/sangre , Estudios Longitudinales , Masculino , Riesgo , Simpaticolíticos/uso terapéutico , Triglicéridos/sangre , Vasodilatadores/uso terapéutico
5.
Arch Intern Med ; 153(18): 2125-9, 1993 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-8379804

RESUMEN

BACKGROUND: To develop a simple screening and diagnostic test for primary aldosteronism and to compare it with established techniques. DESIGN: Comparison of several techniques for screening, diagnosis, and differentiation of primary aldosteronism using normotensive and hypertensive subjects. METHODS: Four hundred thirty-four normotensive subjects, 263 essential hypertensive subjects, 48 subjects with primary aldosteronism due to a unilateral adrenal adenoma, and 14 in whom primary aldosteronism was associated with findings of bilateral hyperaldosteronism were studied. Plasma renin activity and plasma aldosterone were measured in venous blood obtained at 8 AM after 2 hours of ambulation and compared with established suppressive (plasma aldosterone) and stimulatory (plasma renin activity) maneuvers used for the diagnosis of primary aldosteronism. RESULTS: The ratio of plasma aldosterone to plasma renin activity provided complete separation of patients with primary aldosteronism from the normal and essential hypertensive groups. Moreover, based on the use of traditional localizing procedures separating unilateral hyperaldosteronism due to a solitary adenoma from bilateral hyperaldosteronism, confirmed by surgical intervention in the former subgroup, the ratio provided differentiation of these two forms of primary aldosteronism. CONCLUSIONS: The use of the plasma aldosterone to plasma renin activity ratio appears to be useful in the screening, diagnosis, and differentiation of unilateral and bilateral forms of primary aldosteronism. These observations may also be applicable to patients receiving some antihypertensive medications.


Asunto(s)
Aldosterona/sangre , Hiperaldosteronismo/diagnóstico , Renina/sangre , Adulto , Diagnóstico Diferencial , Humanos , Hiperaldosteronismo/clasificación , Persona de Mediana Edad , Sensibilidad y Especificidad
6.
Arch Intern Med ; 139(5): 589-90, 1979 May.
Artículo en Inglés | MEDLINE | ID: mdl-443954

RESUMEN

Localization of adrenal lesions in various adrenal disorders can be difficult. An attempt to identify the adrenal tumors in ten patients with pheochromocytoma, Cushing's syndrome, or primary aldosteronism was made using computerized tomographic (CT) scans. The adrenal tumor was visualized in eight patients. The CT scan appears to be a promising noninvasive technique for localization of adrenal tumors.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Hipertensión/etiología , Tomografía Computarizada por Rayos X , Neoplasias de las Glándulas Suprarrenales/complicaciones , Síndrome de Cushing/complicaciones , Síndrome de Cushing/diagnóstico por imagen , Humanos , Hiperaldosteronismo/complicaciones , Hiperaldosteronismo/diagnóstico por imagen , Feocromocitoma/diagnóstico por imagen
7.
Arch Intern Med ; 144(10): 1963-5, 1984 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6385894

RESUMEN

To test the utility of a qualitative chloride titrator strip in facilitating compliance with a reduced sodium intake diet, we enrolled 32 patients into a randomized crossover trial comprising two study periods of four weeks each. The study periods were begun after the patients had undergone extensive instruction in the diet and the use of the strip. A high degree of correlation between the patient's and the laboratory's interpretation of the strip result was identified in 29 of the subjects. Ability to use the strip was not related to level of education. A total of 12 patients achieved compliance with the diet when using the strips. Of these, nine were able to achieve compliance without the strips. Ten patients (30%) had significantly lower sodium intake when using the strips than when they did not use them. We conclude that the use of the chloride titrator strip can be mastered by most patients and, in conjunction with dietary counseling, can facilitate compliance with a reduced sodium intake diet.


Asunto(s)
Cloruros/orina , Dieta Hiposódica , Cooperación del Paciente , Autocuidado , Adulto , Presión Sanguínea , Ensayos Clínicos como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Autocuidado/métodos , Cloruro de Sodio/orina
8.
Arch Intern Med ; 139(5): 529-33, 1979 May.
Artículo en Inglés | MEDLINE | ID: mdl-443947

RESUMEN

Changes in blood pressure, heart rate, electrolyte excretion, and the renin-angiotensin-aldosterone system were monitored before and after minoxidil was added to a regimen of a diuretic and propranolol hydrochloride in 12 severely hypertensive patients. None required more than 40 mg of minoxidil daily for control. On a constant intake, urinary sodium excretion decreased, while urinary potassium excretion remained stable. Heart rate, body weight, and plasma volume increased, while creatinine clearance did not change. Although plasma renin activity increased fourfold, the plasma aldosterone concentration did not increase. Six subjects were restudied after two months of minoxidil treatment. Although blood pressure control continued to be excellent in these subjects, plasma renin values and plasma volume had returned to pretreatment levels. These studies suggest that minoxidil rapidly and effectively lowers blood pressure. Although sodium retention accompanies minoxidil administration acutely, the effect is independent of aldosterone and may be transient.


Asunto(s)
Aldosterona/sangre , Presión Sanguínea/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Minoxidil/farmacología , Pirimidinas/farmacología , Renina/sangre , Sodio/orina , Adulto , Volumen Sanguíneo/efectos de los fármacos , Creatinina/sangre , Diuréticos/uso terapéutico , Frecuencia Cardíaca , Humanos , Hipertensión/metabolismo , Persona de Mediana Edad , Minoxidil/administración & dosificación , Potasio/orina , Propranolol/uso terapéutico , Factores de Tiempo
9.
Arch Intern Med ; 142(7): 1326-30, 1982 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7046672

RESUMEN

The pathogenesis of edema and hyponatremia in chronic obstructive lung disease (COLD), is poorly understood. Previously, in nonedematous patients with hypercapnia, small increases in plasma renin activity occurred, which prompted this study. In 25 hypercapnic, edematous, often hyponatremic patients with COLD, we measured renal hemodynamics, H2O, and sodium (Na+) excretion, plasma levels of renin activity (PRA), plasma levels of aldosterone (PA), and the plasma arginine vasopressin (AVP)-osmolality relationship. A high prevalence of elevated PRA, PA, and AVP levels excessively high for plasma osmolality was observed. Elevated PRA and Pa correlated with the inability to excrete Na+; an elevated AVP level correlated with the inability to excrete H2). These data suggest that, in conjunction with the hypercapnia-hypoxia-mediated disturbance in renal function, stimulation of the renin-aldosterone level and of the AVP systems contributes, respectively, to edema formation and to hyponatremia in advanced COLD.


Asunto(s)
Edema/metabolismo , Hiponatremia/metabolismo , Enfermedades Pulmonares Obstructivas/metabolismo , Aldosterona/metabolismo , Arginina Vasopresina/metabolismo , Edema/complicaciones , Humanos , Hipercapnia/metabolismo , Hiponatremia/complicaciones , Riñón/metabolismo , Enfermedades Pulmonares Obstructivas/complicaciones , Persona de Mediana Edad , Concentración Osmolar , Renina/metabolismo , Sodio/metabolismo , Agua/metabolismo
10.
Arch Intern Med ; 157(21): 2489-94, 1997 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-9385301

RESUMEN

BACKGROUND: This report is part of a larger, multicenter, placebo-controlled study designed to test the effects of low and high salt intake on the antihypertensive action of enalapril maleate or isradipine in salt-sensitive, hypertensive patients. OBJECTIVE: To present our findings with respect to the effects of race, age, sex, and weight on the blood pressure response to low and high salt intake in salt-sensitive hypertensive patients before randomization into the larger study. PATIENTS AND METHODS: After 3 week (weeks -9 to -6) of ad lib salt intake (100-200 mmol/d of sodium), 1916 patients whose sitting diastolic blood pressure was between 95 and 115 mm Hg entered a 3-week period (week -6 to -3) of low salt intake (50-80 mmol/d of sodium) and then a 3-week period (week -3 to 0) of high salt intake (200-250 mmol/d of sodium). Of the 1916 patients, 624 were identified as being sensitive to salt by demonstrating an increase in sitting diastolic blood pressure of equal to or more than 5 mm Hg from the low to high salt intake. Of these patients, 367 were white, 156 were black, 92 were Hispanic, 8 were Asian, and 1 was American Indian. Also, 315 were men and 309, women; 351 were 55 years or younger and 273 were older than 55 years; and 195 had a body mass index of 27 or less and 429 had a body mass index higher than 27. RESULTS: The sitting blood pressure decreased with salt restriction and increased with salt load in all groups of patients (P < .001). There were no statistically significant differences in the blood pressure changes to salt changes by race, age, sex, and weight. CONCLUSIONS: This large, multicenter study did not demonstrate any statistically significant effect of race, age, sex, and weight on blood pressure response to salt changes in salt-sensitive hypertensive patients.


Asunto(s)
Envejecimiento/metabolismo , Presión Sanguínea/efectos de los fármacos , Peso Corporal , Hipertensión/etiología , Factores Sexuales , Sodio en la Dieta/efectos adversos , Índice de Masa Corporal , Femenino , Humanos , Hipertensión/fisiopatología , Modelos Lineales , Masculino , Persona de Mediana Edad , Grupos Raciales , Sodio en la Dieta/administración & dosificación
11.
Endocrinology ; 101(1): 279-83, 1977 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16742

RESUMEN

To examine the direct effects of dopamine on renin release, the in vitro rat kidney slice system, devoid of hemodynamic and humoral effects, was chosen. In the presence of an antioxidant, ascorbic acid (6 X 10(-4)M), a significant dose-related stimulation of renin release was observed with addition of 10(-5)M and higher concentrations of dopamine. When the monoamine oxidase inhibitor, pheniprazine (1 X 10(-5)M) was added, significant, dose-related stimulation of renin release was observed with 10(-8)M and higher concentrations of dopamine. Dopamine-induced renin release was not inhibited by the presence of the alpha-adrenergic antagonist, phentolamine (9 X 10(-4)M), the dopaminergic antagonist, haloperidol (5 X 10(-5)M) or the neural uptake inhibitor, cocaine (1 X 10(-5)M). However, the presence of the beta-adrenergic antagonist, propranolol (2 X 10(-4)M) completely inhibited dopamine-induced renin release. These studies indicate that dopamine can directly stimulate renin release in the absence of effects of hemodynamic factors, alterations in sodium metabolism or release of endogenous adrenergic agents. Further, this direct effect of dopamine on renin release appears to be mediated by an agonistic effect on the juxtaglomerular beta receptor rather than by the presence of a specific dopaminergic receptor for renin release.


Asunto(s)
Dopamina/farmacología , Riñón/metabolismo , Renina/metabolismo , Animales , Ácido Ascórbico/farmacología , Cocaína/farmacología , Relación Dosis-Respuesta a Droga , Haloperidol/farmacología , Hidrazinas/farmacología , Técnicas In Vitro , Aparato Yuxtaglomerular/metabolismo , Riñón/efectos de los fármacos , Masculino , Fentolamina/farmacología , Propranolol/farmacología , Ratas
12.
Endocrinology ; 116(5): 1712-6, 1985 May.
Artículo en Inglés | MEDLINE | ID: mdl-3886365

RESUMEN

The effect in the rat of alloxan diabetes (with and without insulin treatment) on renin and aldosterone secretion was examined. Rats with diabetes for 7 weeks were found to have lower PRA than nondiabetic controls. The decrease in PRA appeared to result from insulin deficiency since PRA was normal in diabetic rats given insulin. In a second set of animals, which were killed after 3 weeks, in vitro measurements of aldosterone production by perifused adrenal capsular tissue were carried out. Production of aldosterone was greatest by adrenal capsular tissue from insulin-treated diabetic rats where both basal and potassium-stimulated aldosterone production were higher than diabetic rats not given insulin. Although the reduced aldosterone production associated with untreated diabetes may have been a result of reduced in vivo exposure of adrenal tissue to angiotensin II, a chronic adrenotrophic influence of insulin could not be ruled out. In summary, insulin appears to be necessary for normal renin and aldosterone secretion in the diabetic rat.


Asunto(s)
Aldosterona/metabolismo , Diabetes Mellitus Experimental/metabolismo , Insulina/deficiencia , Renina/metabolismo , Animales , Insulina/farmacología , Masculino , Potasio/sangre , Ratas , Ratas Endogámicas
13.
Hypertension ; 11(3 Pt 2): II16-20, 1988 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3280487

RESUMEN

Diuretics have traditionally been the keystone of antihypertensive therapy. A variety of clinical trials, designed to examine the benefit of blood pressure reduction in decreasing morbidity and mortality from hypertension-related cardiovascular disease, have surprisingly failed to show a decrease in coronary artery disease death rate, although other forms of vascular disease were impressively reduced. These trials have consistently used diuretics as the initial therapeutic choice. Such observations have stimulated a reevaluation of the "stepped-care" approach and a critical appraisal of diuretic effects. This review examines the efficacy of diuretics in reducing blood pressure and attempts to identify individuals most likely to respond to these agents. The side effects of diuretic therapy are reviewed in hemodynamic, cardiac, metabolic, and symptomatic terms, but because some of these aspects of diuretic or antihypertensive therapy are detailed elsewhere in this monograph, the present discussion focuses on cardiac, metabolic, hemodynamic, and symptomatic effects. Finally, alternative therapeutic options and guidelines for therapy are outlined.


Asunto(s)
Diuréticos/efectos adversos , Hipertensión/tratamiento farmacológico , Arritmias Cardíacas/inducido químicamente , Diuréticos/uso terapéutico , Humanos , Hipopotasemia/inducido químicamente , Enfermedades Metabólicas/inducido químicamente
14.
Hypertension ; 18(3 Suppl): I82-6, 1991 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1889861

RESUMEN

Hypertension may result from a variety of abnormalities. The rise in blood pressure may trigger other secondary events that further influence cardiovascular homeostasis. The ability to measure some markers associated with hypertension or the responsiveness of blood pressure to nutritional interventions or to specific therapeutic agents may also have pathogenetic implications. The ultimate goal of further knowledge in this area should be to understand the fundamental abnormalities responsible for hypertension. Such insight would permit more effective treatment and, perhaps, primary prevention of this ubiquitous and multifaceted disorder.


Asunto(s)
Hipertensión/fisiopatología , Antihipertensivos/farmacología , Presión Sanguínea/efectos de los fármacos , Dieta , Humanos , Hipertensión/etiología , Resistencia a la Insulina , Potasio/farmacología , Renina/sangre
15.
Hypertension ; 27(3 Pt 2): 481-90, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8613190

RESUMEN

A variety of different techniques have been used for the assessment of the blood pressure response to changes in salt and water balance in humans. These have generally been found to be reproducible and to yield congruent results. This review surveys the characteristics of subjects identified as salt sensitive and salt resistant by different investigators from demographic and physiological perspectives.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Hipertensión/fisiopatología , Sodio en la Dieta/administración & dosificación , Humanos , Hipertensión/etiología
16.
Hypertension ; 5(5 Pt 2): III132-8, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6313523

RESUMEN

Diuretic therapy is frequently accompanied by undesirable biochemical changes and side-effects. Two multicenter trials compared the effects of captopril combined with a diuretic to the administration of either agent alone in mild-to-moderate hypertensives. In addition to blood pressure, effects on serum potassium, uric acid, glucose, and cholesterol were examined. The first study (Study A) was conducted on 210 such patients randomly assigned to receive: 1) hydrochlorothiazide (H) 15 mg three times daily (t.i.d.); 2) captopril (C) 25 mg t.i.d.; or 3) C + H for 6 weeks. The second study (Study B) involved 415 patients randomly assigned to receive: 1) C 25 mg twice daily (b.i.d.) + H 25 mg b.i.d.; 2) C 50 mg b.i.d. + H 25 mg b.i.d.; 3) C 50 mg b.i.d. + placebo b.i.d.; 4) placebo b.i.d. + H 25 mg b.i.d.; or 5) placebo b.i.d. + placebo b.i.d. for 6 weeks. In both Studies A and B, all patients except those receiving placebo only (Study B-5) had significant (p less than 0.05) blood pressure reductions. In Study A, the combination of C + H (A-3) produced a significantly greater (p less than 0.001) reduction in blood pressure than either agent alone. In Study B, both C + H groups (B-1, B-2) had a significantly greater (p less than 0.01) blood pressure reduction than that seen with C alone (B-3). In Study A, those treated with H alone (A-1) had a significant (p less than 0.05) reduction in serum potassium and increases in uric acid, glucose, and cholesterol when compared to C alone (A-2) where no changes in these parameters were observed.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina , Captopril/uso terapéutico , Hidroclorotiazida/uso terapéutico , Hipertensión/tratamiento farmacológico , Prolina/análogos & derivados , Glucemia/análisis , Presión Sanguínea/efectos de los fármacos , Colesterol/sangre , Ensayos Clínicos como Asunto , Mareo/inducido químicamente , Quimioterapia Combinada , Femenino , Cefalea/inducido químicamente , Humanos , Hidroclorotiazida/efectos adversos , Hipertensión/metabolismo , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Potasio/sangre , Ácido Úrico/sangre
17.
Hypertension ; 11(2 Pt 2): I229-32, 1988 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2894358

RESUMEN

We evaluated the response to salt restriction in hypertensive patients receiving drugs. By restricting their salt intake to less than 80 mmol of sodium per day for 3 months, 50% of patients reaching goal compliance were able to discontinue diuretics. The literature also reveals responses to a low salt diet. Salt restriction augmented the hypotensive effect of chlorthalidone in two investigations, but not in another, and the hypotensive effect of beta-blockers in three trials. Sodium intake of 10 mmol/day caused a much greater decrease in blood pressure in response to a single dose of captopril than did a sodium diet of 200 mmol/day. In patients receiving various fixed regimens for 2 months, salt restriction decreased blood pressure in all but those receiving calcium blockers. A single dose of nifedipine lowered blood pressure more in patients receiving 350 mmol of sodium per day than in the same patients given 150 or 10 mmol/day. Verapamil for 3 days was more effective in patients receiving 212 mmol of sodium per day than in the same subjects receiving 9 mmol/day. Nitrendipine caused a greater decrease in diastolic blood pressure in patients who did not reduce salt intake compared to those who did. Salt restriction appears useful in salt-sensitive patients who receive beta-blockers, diuretics, converting enzyme inhibitors, or centrally acting drugs. Calcium channel entry blockers may not require salt restriction to maximize their effect.


Asunto(s)
Antihipertensivos/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Dieta Hiposódica , Hipertensión/terapia , Antagonistas Adrenérgicos beta/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Ensayos Clínicos como Asunto , Diuréticos/uso terapéutico , Humanos
18.
Hypertension ; 18(1): 67-71, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1860713

RESUMEN

Salt sensitivity has been implicated in the age-related increase in blood pressure. We studied the reproducibility of a rapid method for assessing sodium sensitivity and resistance of blood pressure as well as the effect of age on this phenomenon. Blood pressure after volume expansion with 2 l intravenous saline (0.9%) over 4 hours was compared with that after 1 day of 10 mmol sodium chloride intake and 3 and 40 mg oral doses of furosemide. Normal and hypertensive subjects (n = 28) were studied twice within a year. Cross-sectional observations of the effect of age were made from studies in 230 hypertensive and 430 normotensive subjects. Longitudinal observations of blood pressure change over time were made 10 or more years after categorization of sodium responsivity in 31 subjects. The blood pressure response was reproducible in 28 subjects studied twice (r = 0.56, p less than 0.002). Four subjects changed salt-responsiveness status and six were indeterminate on restudy. Sodium sensitivity of blood pressure increased significantly with increasing age in the entire population (n = 660, r = -0.38, p less than 0.001). The relation was more striking in hypertensive subjects (n = 230, r = -0.31, p less than 0.001) in whom a progressive increase in salt sensitivity with decades was seen than in the normotensive group (n = 430, r = -0.19, p less than 0.01) in whom salt sensitivity was not observed until the sixth decade. Salt-sensitive subjects had a significantly greater increase in systolic (p less than 0.001) and diastolic (p less than 0.01) pressure over time than those who were salt-resistant. Salt sensitivity is a reproducible phenomenon that is related to the age-associated increase in blood pressure characteristic of industrialized societies. In addition, salt sensitivity can be shown to be a predictor of subsequent, age-related blood pressure increase.


Asunto(s)
Envejecimiento/fisiología , Presión Sanguínea/efectos de los fármacos , Volumen Sanguíneo/fisiología , Cloruro de Sodio/farmacología , Adulto , Anciano , Estudios Transversales , Diástole , Furosemida/farmacología , Humanos , Hipertensión , Estudios Longitudinales , Persona de Mediana Edad , Sístole
19.
Hypertension ; 4(5 Pt 2): III14-9, 1982.
Artículo en Inglés | MEDLINE | ID: mdl-7049928

RESUMEN

This review briefly considers the hypothesis that a generous dietary sodium intake contributes to the development or maintenance of essential hypertension. Three lines of evidence are presented that are not mutually exclusive. Epidemiological studies examining sodium intake, prevalence of hypertension, and increases of blood pressure with age provide circumstantial support for the concept that hypertension is related to sodium intake. Analyses of cellular electrolyte transport suggest that hypertensives and their relatives are at a disadvantage with respect to extruding sodium from cells. A conceptual framework indicates that blood pressure is determined by a balance between the natriuretic effect of increased blood pressure and the pressor effect of sodium retention. Clinical studies in humans support the sodium hypothesis. The kidney's ability to excrete sodium and its sodium regulatory system are genetically determined. In hypertensive humans, blood pressure is directly correlated with total body and exchangeable sodium, a relationship that increases with age. Groups at risk for hypertension excrete sodium less well then those at less risk. Yet both hypertensives and normotensives exhibit heterogeneous blood pressure responses when sodium-loaded or -depleted. It has not been shown that sodium restriction will prevent the development of hypertension in normal individuals; however, it is clear that sodium restriction is an important aspect of management. In three prospective randomized controlled trials, practical sodium restriction lowered blood pressure by 8 mm Hg. Such a decrease would lower cardiovascular morbidity by 10% to 15%. Were means available to detect "salt-sensitive" hypertensives, sodium restriction could be conducted in a more appropriate fashion.


Asunto(s)
Hipertensión/inducido químicamente , Fenómenos Fisiológicos de la Nutrición , Sodio/administración & dosificación , Adulto , Anciano , Población Negra , Presión Sanguínea/efectos de los fármacos , Dieta Hiposódica , Relación Dosis-Respuesta a Droga , Humanos , Hipertensión/dietoterapia , Hipertensión/prevención & control , Riñón/fisiopatología , Masculino , Persona de Mediana Edad , Natriuresis , Potasio/farmacología , Sodio/efectos adversos , Sodio/metabolismo , Población Blanca
20.
Hypertension ; 10(4): 437-42, 1987 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-3653972

RESUMEN

To investigate the effect on blood pressure of a modest increase in dietary potassium intake, 38 healthy, free-living families were enrolled in a study involving 4 weeks of potassium supplementation. This was preceded by collection of five baseline measurements of blood pressure and urinary electrolyte excretion and followed by a 4-week recovery period. Although there was a significant increase in urinary potassium excretion during supplementation in both adults and children (p less than 0.001), there were no significant changes in systolic, diastolic, or mean arterial blood pressure. Height and weight increased significantly in children (p less than 0.001), and weight increased in adults (p less than 0.01) over the course of the study. Multivariate analysis of variance of blood pressure controlling for these confounding variables failed to reveal any effect of the potassium supplementation on blood pressure. These results suggest that increasing intake of dietary potassium alone in a healthy, free-living normotensive population is unlikely to have a discernible effect on blood pressure.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Dieta , Potasio/administración & dosificación , Adolescente , Adulto , Estatura/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Niño , Familia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Potasio/orina , Sodio/orina
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