RESUMEN
BACKGROUND: Atherosclerosis of the thoracic aorta is associated with stroke. The association between hypertension, a major risk factor for stroke, and aortic atherosclerosis has not been determined in the general population. METHODS AND RESULTS: Transesophageal echocardiography was performed in 581 subjects, a random sample of the Olmsted County (Minnesota) population aged >/=45 years participating in the Stroke Prevention: Assessment of Risk in a Community (SPARC) study. Blood pressure was assessed by multiple office measurements and 24-hour ambulatory blood pressure monitoring. The association between blood pressure variables and aortic atherosclerosis was evaluated by multiple logistic regression, adjusting for other associated variables. Among subjects with atherosclerosis, blood pressure variables associated with complex aortic atherosclerosis (protruding plaques >/=4 mm thick, mobile debris, or ulceration) were determined. Age and smoking history were independently associated with aortic atherosclerosis of any degree (P:=0.001) and with complex atherosclerosis (P:=0.002), whereas sex, diabetes mellitus, and body mass index were not. Multiple systolic and pulse pressure variables (office and ambulatory), but none of the diastolic blood pressure variables, were associated with atherosclerosis and complex atherosclerosis, adjusting for age and smoking. Among subjects with atherosclerosis, the odds of complex atherosclerosis increased as ambulatory out-of-bed systolic blood pressure increased (odds ratio 1.43 per 10 mm Hg increase, 95% CI 1. 10 to 1.87) and with hypertension treatment, adjusting for age and smoking history. CONCLUSIONS: High blood pressure is independently associated with aortic atherosclerosis. Among subjects with atherosclerosis, high blood pressure is associated with complex atherosclerosis.
Asunto(s)
Enfermedades de la Aorta/complicaciones , Arteriosclerosis/complicaciones , Hipertensión/complicaciones , Distribución por Edad , Anciano , Anciano de 80 o más Años , Aorta Torácica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
BACKGROUND: The aneroid sphygmomanometer is commonly used for the indirect measurement of blood pressure despite significant concerns about its accuracy. Although the mercury sphygmomanometer is highly accurate, there are concerns about the environmental toxicity of mercury. In response to various external pressures to become essentially mercury free, the Mayo Clinic, Rochester, Minn, has replaced many mercury sphygmomanometers with aneroid devices. Since 1993, a maintenance protocol has been in place to ensure proper function and accuracy of these devices. METHODS: We assessed the accuracy of 283 aneroid devices using as the reference standard a digital pressure and vacuum meter that was calibrated using a mercury sphygmomanometer. RESULTS: The mean +/- SD values from the aneroid device in millimeters of mercury at each reference point (at 20-mm Hg intervals from 60 to 240 mm Hg defined by the reference device) were 59.9 +/- 1.9 at 60; 79.9 +/- 1.9 at 80; 100.0 +/- 1.8 at 100; 120.3 +/- 1.8 at 120; 140.7 +/- 1.4 at 140; 160.7 +/- 1.7 at 160; 180.9 +/- 1.3 at 180; 200.7 +/- 5.0 at 200; 221.0 +/- 1.3 at 220; and 240.8 +/- 1.6 at 240 (r = 0.99; P<.001). The values from the aneroid device underestimated those of the reference device by a mean of 0.5 mm Hg (95% confidence interval, 0.3-0.7). Virtually 100% of the values from the aneroid device were within the 4-mm Hg range recommended by the Association for the Advancement of Medical Instrumentation. CONCLUSION: Aneroid sphygmomanometers provide accurate pressure measurements when a proper maintenance protocol is followed.
Asunto(s)
Determinación de la Presión Sanguínea/instrumentación , Esfigmomanometros , Diseño de Equipo , Hospitales , Humanos , Servicio Ambulatorio en Hospital , Sensibilidad y EspecificidadRESUMEN
We investigated whether blood pressures are higher in normotensive offspring of hypertensive parents than in normotensive offspring of normotensive parents outside the physician's office and, if so, whether these higher blood pressures are dependent on the level of dietary sodium intake. We compared 24-hour ambulatory blood pressure profiles between 11 normotensive sons of two hypertensive parents and 11 normotensive sons of two normotensive parents; profiles were recorded after 1 week of a low sodium diet (10 meq/day) and after 1 week of a high sodium diet (200 meq/day). The sons of hypertensive parents were on average 6 years older than the sons of normotensive parents (47 +/- 5 [SD] versus 41 +/- 4 years, p < 0.05). The shift from low to high sodium diet did not significantly change the magnitude of differences in office or ambulatory blood pressures between the groups (i.e., no group-by-diet interaction); thus, we assessed group effects by contrasting blood pressure means for each group pooled across diets. Age-adjusted office blood pressure was higher in sons of hypertensive parents than in sons of normotensive parents (116 +/- 7/80 +/- 6 versus 111 +/- 7/75 +/- 6 mm Hg; p = 0.020 for systolic and p = 0.003 for diastolic blood pressure).(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Presión Sanguínea , Hipertensión/genética , Anciano , Atención Ambulatoria , Determinación de la Presión Sanguínea/métodos , Ritmo Circadiano , Frecuencia Cardíaca , Humanos , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Consultorios Médicos , Valores de Referencia , Sueño/fisiología , Vigilia/fisiologíaRESUMEN
At the community level, the effect of national programs in increasing hypertension awareness, prevention, treatment, and control is unclear. This study evaluated the degree of detection and control of high blood pressure in a random population-based sample of Olmsted County, Minnesota, residents >/=45 years old, of whom 636 subjects among 1245 eligible residents agreed to participate. Home interview and home and office measurements of blood pressure were used to estimate awareness, treatment, and control rates for hypertension in the community. Mean blood pressures (+/-SD) were 138/80+/-20/12 mm Hg for men and 137/76+/-23/11 mm Hg for women. The overall prevalence of hypertension was 53%. The percentage of subjects with treated and controlled hypertension was 16.6%. Thirty-nine percent of subjects were unaware of their hypertension. Despite clinical trial evidence of reduced morbidity and mortality with antihypertensive therapy, recently reported national data suggest a leveling-off trend for treatment and control of hypertension. This population-based study supports these observations and suggests that at a community level, hypertension awareness and blood pressure control rates are suboptimal, presumably because of decreased attention to the detection and control of hypertension.
Asunto(s)
Servicios de Salud Comunitaria , Hipertensión/prevención & control , Anciano , Concienciación , Monitores de Presión Sanguínea , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To determine whether genetic and non-genetic components of interindividual variation in systolic and diastolic blood pressure are constant throughout the day or are time or activity dependent. METHODS: We obtained 24 h ambulatory blood pressure recordings in 263 members of 68 unrelated nuclear families (i.e. parents and their offspring) representative of the Caucasian population of Rochester, MN, USA. Using the time each patient got into bed as a reference point, we identified 198 records in which this reference point was preceded by eight consecutive active hours (out of bed) and followed by four consecutive inactive hours (in bed) in which four or more blood pressure readings taken each hour were judged to be technically satisfactory. For each hourly mean for systolic and diastolic blood pressure, we estimated total interindividual variance, variance associated with concomitant variables (generation; sex within generation strata; and age, height, weight, body mass index, and abdomen-to-hip ratio within generation and sex strata), and variance associated with additive genetic effects (i.e. the chief cause of resemblance between relatives). To assess trends in each component of interindividual blood pressure variance over the 12 h period, we estimated the slope of the linear regression line fit to the hourly estimates. RESULTS: For systolic blood pressure, total interindividual variance did not change significantly (slope of regression line = -0.23, P = 0.717). In contrast, total interindividual variance for diastolic blood pressure was greater during active hours than inactive hours (slope of regression line = -5.53, P < 0.001). For both systolic and diastolic blood pressure, variance associated with the concomitant variables was greater during active hours than during inactive hours (for systolic blood pressure slope of regression line = -2.98, P = 0.001; for diastolic blood pressure slope of regression line = -6.14, P < 0.001). Likewise, for both systolic and diastolic blood pressure, variance associated with additive genetic effects was also greater during active hours than during inactive hours (for systolic blood pressure slope of regression line = -1.65, P = 0.090; for diastolic blood pressure slope of regression line = -1.47, P = 0.018). CONCLUSIONS: This study demonstrates that components of interindividual variation in blood pressure are not constant, but are time or activity dependent.
Asunto(s)
Monitoreo Ambulatorio de la Presión Arterial , Presión Sanguínea/genética , Variación Genética/genética , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Minnesota , Linaje , Análisis de Regresión , Estudios RetrospectivosRESUMEN
Pharmacogenetic investigation seeks to identify genetic factors that contribute to interpatient and interdrug variation in responses to antihypertensive drug therapy. Classical studies have characterized single gene polymorphisms of drug metabolizing enzymes that are responsible for large interindividual differences in pharmacokinetic responses to several antihypertensive drugs. Progress is being made using candidate gene and genome scanning approaches to identify and characterize many additional genes influencing pharmacodynamic mechanisms that contribute to interindividual differences in responses to antihypertensive drug therapy. Knowledge of polymorphic variation in these genes will help to predict individual patients' blood pressure responses to antihypertensive drug therapy and may also provide new insights into molecular mechanisms responsible for elevation of blood pressure.
Asunto(s)
Antihipertensivos/farmacología , Hipertensión/tratamiento farmacológico , Farmacogenética/métodos , Biotransformación/genética , Presión Sanguínea/efectos de los fármacos , Proteínas de Unión a Calmodulina/genética , Proteínas de Unión a Calmodulina/metabolismo , Ensayos Clínicos como Asunto , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Genotipo , Humanos , Hipertensión/genética , Hipertensión/metabolismo , Polimorfismo Genético , Sistema Renina-Angiotensina/genéticaRESUMEN
The safety and efficacy of orally administered celiprolol, a new beta 1-selective adrenergic blocking drug with peripheral beta 2-agonist properties, were assessed in 91 patients with mild to moderate systemic hypertension (supine diastolic blood pressure [BP] 95 to 114 mm Hg without medication) using a placebo-controlled, double-blind, randomized, titration-to-effect study design. All patients received placebo for 4 weeks and were then randomized to receive placebo (n = 46) or once-daily celiprolol (n = 45), which was titrated every 2 weeks (200, 400, 600 mg/day) over a 6-week period to achieve a reduction in supine diastolic BP to less than or equal to 90 mm Hg. Plasma lipids and lipoproteins were also assessed at baseline, during placebo and after randomization to active therapy in a subgroup of patients. Compared with placebo, celiprolol reduced supine and standing BP (reduction of supine BP -0.4/-2.1 mm Hg with placebo, -5.7/-6.4 with celiprolol, p less than 0.05; reduction of standing BP -1.7/-1.0 with placebo, -7.2/-4.9 with celiprolol, p less than 0.05). Supine heart rate was reduced by 6.8 beats/min with celiprolol compared with 2.0 beats/min with placebo (p less than 0.05). No differences were seen when the effects of placebo and celiprolol on plasma lipoproteins were compared. Celiprolol is a safe, effective and well tolerated once-daily antihypertensive drug and has no detrimental effects on plasma lipids.
Asunto(s)
Antihipertensivos/uso terapéutico , Hipertensión/tratamiento farmacológico , Propanolaminas/uso terapéutico , Antihipertensivos/efectos adversos , Presión Sanguínea/efectos de los fármacos , Celiprolol , Ensayos Clínicos como Asunto , Método Doble Ciego , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hipertensión/sangre , Hipertensión/fisiopatología , Lípidos/sangre , Masculino , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Propanolaminas/administración & dosificación , Propanolaminas/efectos adversos , Distribución AleatoriaRESUMEN
The objectives of this study were to establish reference values and define the determinants of left atrial appendage (LAA) flow velocities in the general population. LAA flow velocities (contraction and filling velocities) were assessed by transesophageal echocardiography in 310 subjects aged > or = 45 years, sampled from the population-based Stroke Prevention: Assessment of Risk in a Community study. All subjects were in sinus rhythm, with preserved left ventricular systolic function (ejection fraction > or = 50%), and without valvular disease. Values of LAA contraction and filling velocities were established for various age groups in the population. Age was negatively associated with LAA contraction and filling velocities, which decreased by 4.1 cm/s (p < 0.001) and 2.0 cm/s (p < 0.01) for every 10 years of age, respectively. Contraction velocities were 5 cm/s higher in men than in women (p < 0.05). After adjusting for age and sex, heart rate was independently associated with LAA contraction velocities (p < 0.001; nonlinear association). Body surface area, left atrial size, left ventricular mass index, and a history of previous cardiac disease or hypertension showed no significant association with LAA flow velocities (p > 0.05). Furthermore, detailed analysis of 24-hour ambulatory blood pressure data (available in 253 subjects) showed no association between various blood pressure parameters (systolic and diastolic blood pressure, out-of-bed and in-bed measurements) and LAA flow velocities (all p > 0.05). In summary, the present study establishes the reference values for LAA flow velocities in a large sample of the general population. LAA flow velocities progressively decline with age in subjects with preserved left ventricular systolic function.
Asunto(s)
Función Ventricular Izquierda/fisiología , Factores de Edad , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Ecocardiografía , Ecocardiografía Transesofágica , Frecuencia Cardíaca/fisiología , Humanos , Persona de Mediana Edad , Contracción Miocárdica/fisiología , Valores de Referencia , Factores SexualesRESUMEN
Of the approximately 58 million Americans with hypertension, the majority have only mild increases in blood pressure and individually are at low risk. Large group studies, however, have demonstrated the efficacy of treating mild hypertension. Public health efforts during the past 16 years have increased the number of hypertensive patients made aware of their condition and brought into treatment. A major problem, however, is consistently maintaining patients on long-term therapy. A large number of nonpharmacologic and pharmacologic treatments have become available for the management of hypertension. These treatments must be applied individually to enhance benefit, minimize potential harm, and increase the likelihood of long-term compliance for what is often a lifelong disorder. For accomplishing this goal, a thorough understanding of important characteristics of both the individual patient and the available therapeutic modalities is needed.
Asunto(s)
Hipertensión/terapia , Antagonistas Adrenérgicos beta/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Interacciones Farmacológicas , Quimioterapia Combinada , Femenino , Humanos , Hipertensión/etiología , Cuidados a Largo Plazo/organización & administración , Masculino , Cooperación del Paciente , Factores de RiesgoRESUMEN
For diabetic patients, a goal blood pressure lower than 130/80-85 mm Hg is strongly supported by clinical trial results. We review the agents, sequence, and dosing used in clinical trials and propose a treatment algorithm. Multiagent antihypertensive therapy is required to attain goal blood pressure in most patients. Step sequences to obtain this goal are suggested. In general, we favor initial therapy with an angiotensin-converting enzyme inhibitor, followed by the addition of a diuretic. The presence of comorbid conditions may dictate variation from this scheme. The effect of antihypertensive agents on established cardiovascular diseases, proteinuria, renal function, and metabolic factors is discussed. Tailored recommendations for specific clinical scenarios are described.
Asunto(s)
Algoritmos , Antihipertensivos/uso terapéutico , Árboles de Decisión , Complicaciones de la Diabetes , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Antagonistas Adrenérgicos beta/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Protocolos Clínicos , Comorbilidad , Diuréticos/uso terapéutico , Esquema de Medicación , Quimioterapia Combinada , Medicina Basada en la Evidencia , Humanos , Hipertensión/diagnóstico , Selección de Paciente , Guías de Práctica Clínica como Asunto , Factores de Riesgo , Resultado del TratamientoRESUMEN
OBJECTIVE: To determine whether the calculated ratio of plasma aldosterone concentration (PAC) to plasma renin activity (PRA), a proposed screening test for primary aldosteronism, provides a renin-independent measure of circulating aldosterone that is suitable to judge whether PAC is inappropriately elevated relative to PRA. SUBJECTS AND METHODS: This study consisting of 221 black and 276 white subjects with previously diagnosed essential hypertension was conducted between 1996 and 2000. Antihypertensive drugs were withdrawn for at least 4 weeks; PAC and PRA were measured while subjects were supine and then seated after 30 minutes of ambulation. The seated measurements were repeated after 4 weeks of oral diuretic therapy with hydrochlorothiazide (25 mg/d). RESULTS: The variation in the aldosterone-renin ratio was strongly and inversely dependent on PRA (R2=0.71; P<.001). When subjects changed position from supine to seated, the increase in mean +/- SD PRA (from 1.18 +/- 1.06 to 1.31 +/- 1.19 ng x mL(-1) x h(-1); P<.001) was associated with an increase in the mean ratio (from 18.6 +/- 52.8 to 25.8 +/- 38.1 h x 10(2); P<.001), whereas the increase in mean +/- SD PRA in response to diuretic therapy (from 1.31 +/- 1.19 to 2.72 +/- 2.67 ng x mL(-1) x h(-1); P=.007) was associated with a decrease in the mean ratio (from 25.8 +/- 38.1 to 16.4 +/- 31.6 h 10(2); P<.001). CONCLUSION: In patients with previously diagnosed essential hypertension, calculation of the aldosterone-renin ratio does not provide a renin-independent measure of circulating aldosterone that is suitable for determining whether PAC is elevated relative to PRA. Because elevation of the aldosterone-renin ratio is predominantly an indicator of low PRA, its perceived value in screening for primary aldosteronism most likely derives from additional diagnostic tests being done in patients with low-renin hypertension.
Asunto(s)
Población Negra/genética , Hiperaldosteronismo/diagnóstico , Hipertensión/diagnóstico , Sistema Renina-Angiotensina/fisiología , Población Blanca/genética , Distribución por Edad , Anciano , Análisis de Varianza , Femenino , Humanos , Hiperaldosteronismo/etnología , Hipertensión/etnología , Modelos Lineales , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Prevalencia , Probabilidad , Radioinmunoensayo , Reproducibilidad de los Resultados , Medición de Riesgo , Sensibilidad y Especificidad , Distribución por SexoRESUMEN
Zomepirac sodium (Zomax) is a nonsteroidal anti-inflammatory agent with analgesic properties which was recently released for clinical use in this country. We report here a case of nonoliguric acute renal failure associated with zomepirac sodium therapy. This acute renal failure improved upon cessation of zomepirac treatment. Renal biopsy disclosed the presence of a tubulointerstitial nephritis, which was thought to have been responsible for the acute renal failure in this patient. Clinicians should be aware of the potential nephrotoxicity of zomepirac sodium and use caution in its administration, especially in patients with compromised intravascular volume status, hypertension, or preexistent chronic renal disease.
Asunto(s)
Lesión Renal Aguda/inducido químicamente , Analgésicos/efectos adversos , Pirroles/efectos adversos , Tolmetina/efectos adversos , Lesión Renal Aguda/patología , Lesión Renal Aguda/orina , Anciano , Creatinina/sangre , Femenino , Humanos , Glomérulos Renales/patología , Tolmetina/análogos & derivadosRESUMEN
OBJECTIVE: To examine the association between atrial fibrillation (AF) and aortic atherosclerosis in the general population. SUBJECTS AND METHODS: Transesophageal echocardiography was performed in 581 subjects, a random sample of the adult Olmsted County, Minnesota, population (45 years of age or older) participating in the Stroke Prevention: Assessment of Risk in a Community (SPARC) study. The frequency of aortic atherosclerosis was determined in 42 subjects with AF and compared with that in 539 subjects without AF (non-AF group). RESULTS: Subjects with AF were significantly older than non-AF subjects (mean +/- SD age, 82+/-10 vs 66+/-13 years, respectively; P<.001) and more commonly had hypertension (28 [66.7%] vs 288 [53.4%], respectively; P=.10). The 2 groups were similar in sex and frequency of diabetes mellitus, hyperlipidemia, or smoking history (P>.10). The odds of aortic atherosclerosis (of any degree) were 2.87 times greater (95% confidence interval [CI], 1.41-5.83; P=.004) and the odds of complex atherosclerosis (protruding atheroma >4 mm thick, mobile debris, or plaque ulceration) were 2.71 times greater (CI, 1.13-6.53; P=.03) in the AF group than in the non-AF group. Age was a significant predictor of aortic atherosclerosis (P<.001). After adjusting for age, the odds of atherosclerosis and complex atherosclerosis were not significantly different between the 2 groups (P=.13 and P=.75, respectively). CONCLUSIONS: In the general population, AF is associated with aortic atherosclerosis, including complex atherosclerosis. This association is related to age since both AF and aortic atherosclerosis are more frequent in the elderly population.
Asunto(s)
Enfermedades de la Aorta/complicaciones , Arteriosclerosis/complicaciones , Fibrilación Atrial/complicaciones , Adulto , Distribución por Edad , Anciano , Enfermedades de la Aorta/diagnóstico por imagen , Arteriosclerosis/diagnóstico por imagen , Arterias Carótidas/diagnóstico por imagen , Ecocardiografía , Ecocardiografía Transesofágica , Femenino , Humanos , Hipertensión/complicaciones , Masculino , Persona de Mediana Edad , Distribución Aleatoria , Factores de Riesgo , Distribución por SexoRESUMEN
The objectives of this study were to determine whether total interindividual variation in blood pressure (BP) differs between inactive and active hours of the day, to identify predictors of interindividual variation in BP, and to assess whether variation associated with any of these identified predictors is greater (or less) during inactive hours than during active hours of the day. We obtained ambulatory BP recordings over 20 consecutive hours (12 active, out of bed [daytime]; and 8 inactive, in bed [nighttime]) in a sample of 240 unrelated, non-Hispanic white adults (138 men; 102 women). We estimated total interindividual variation in BP, and the percentage of interindividual variation associated with measures of age and body size, metabolic traits, catecholamines, erythrocyte cation transport, and renal function. We used linear regression to assess changes in the hourly estimates of total interindividual variation and in variation attributable to each set of predictor traits over the 20 h. In both men and women, total interindividual variation in systolic BP was significantly greater (not less) during inactive hours than during active hours. In addition, in women, total interindividual variation in diastolic BP was as great during inactive hours as during active hours. Each set of traits considered predicted a statistically significant percentage of interindividual variation in BP. None of the sets of traits predicted a greater percentage of interindividual variation during the inactive hours than during the active hours. Measures of age and body size, catecholamines, cation transport and renal function traits predicted significantly less interindividual variation during inactive hours than during active hours of the day. That total interindividual variation in BP is as great or greater during inactive hours than during active hours of the day emphasizes the potential for differences in nighttime BP to contribute to the development of cardiovascular disease. In as much as the predictors of interindividual variation in BP differ between the daytime and nighttime, the causes of variation during these two times may also differ.
Asunto(s)
Monitoreo Ambulatorio de la Presión Arterial , Presión Sanguínea/fisiología , Actividad Motora/fisiología , Adulto , Envejecimiento/fisiología , Peso Corporal/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Caracteres Sexuales , Factores de Tiempo , Población BlancaRESUMEN
Total and ionized calcium, parathyroid hormone, calcitonin, and renin activity were measured in 27 untreated patients with essential hypertension. There was no relationship between any of these parameters and diastolic blood pressure. However, a significant inverse relationship was found between diastolic blood pressure and the ratio of either total or ionized calcium to parathyroid hormone (r = -0.40, P less than 0.05; and r = -0.38, P less than 0.05, respectively). The ratios did not correlate with patient age or plasma renin level. This preliminary finding suggests that the role of plasma calcium in hypertension may need to be analyzed in the context of overall calcium metabolism, as influenced by the parathyroid hormone. The role of an altered relationship between plasma calcium level and parathyroid hormone in the pathophysiology of essential hypertension remains to be studied.
Asunto(s)
Calcio/sangre , Hipertensión/sangre , Hormona Paratiroidea/sangre , Presión Sanguínea , Calcitonina/sangre , Humanos , Hipertensión/fisiopatología , Concentración OsmolarRESUMEN
The aim of this study was to determine whether intraindividual blood pressure (BP) variability, measured by noninvasive ambulatory monitoring, differs between the active (daytime) and inactive (nighttime) periods of the day. We obtained ambulatory BP recordings in 143 healthy adults (95 men, 48 women) from Rochester, Minnesota. Readings were obtained every 10 min for a 24-h period. We calculated the standard deviation of each individual's BP readings about the means for the active period and for the inactive period as measures of intraindividual BP variability. In men, mean within-individual standard deviations for both systolic (SBP) and diastolic blood pressure (DBP) were significantly greater during the inactive period than during the active period (for SBP: 10.3 +/- 2.1 v 11.9 +/- 2.7, P < .0001; for DBP: 8.8 +/- 2.0 v 9.7 +/- 2.5, P = .0027). In women, the mean within-individual standard deviation for SBP did not differ significantly between the active and inactive periods (9.7 +/- 2.2 v 10.3 +/- 2.4, P = 0.225) but for DBP was significantly greater during the inactive period than during the active period (8.1 +/- 2.0 v 9.2 +/- 2.3, P = .020). Statistically significant predictors of intraindividual BP variability included measures of age and body size, metabolic traits, neuroendocrine traits, erythrocyte cation traits, and renal function traits. This study demonstrates that intraindividual BP variability, as measured by noninvasive ambulatory monitoring, is as great or greater during the inactive period as during the active period of the day.
Asunto(s)
Monitoreo Ambulatorio de la Presión Arterial , Presión Sanguínea/fisiología , Ritmo Circadiano/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Valores de Referencia , Factores Sexuales , Factores de TiempoRESUMEN
Noninvasive automatic ambulatory blood pressure monitoring during 24 hours in eight patients with moderate hypertension was used to determine the blood pressure response to lisinopril, an angiotensin-converting enzyme inhibitor. Office, 24-hour ambulatory, awake ambulatory, and sleep ambulatory diastolic blood pressures were decreased from 108 +/- 3, 98 +/- 8, 101 +/- 7, and 87 +/- 14 mm Hg, respectively, at baseline to 83 +/- 4 (P less than or equal to 0.0001), 82 +/- 7 (P less than 0.0001), 84 +/- 7 (P less than 0.0001), and 73 +/- 9 mm Hg (P less than 0.005), respectively, after 20 weeks of lisinopril treatment (dose range, 40 to 80 mg once daily). The diastolic blood pressure loads (percentages of ambulatory diastolic blood pressures more than 90 mm Hg) during 24 hours and during awake hours were 74% +/- 19% and 83% +/- 15%, respectively, at baseline and 24% +/- 19% (P less than 0.0001) and 29% +/- 21% (P less than 0.0001), respectively, during treatment. Heart rate was not altered by lisinopril. In conclusion, lisinopril is an effective antihypertensive agent for the treatment of moderate hypertension, and ambulatory blood pressures and diastolic blood pressure loads are useful for evaluating therapy for hypertension.
Asunto(s)
Atención Ambulatoria , Antihipertensivos/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Enalapril/análogos & derivados , Monitoreo Fisiológico , Adulto , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Enalapril/uso terapéutico , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Lisinopril , Masculino , Persona de Mediana EdadRESUMEN
The blood pressure response to a new sustained-release formulation of nifedipine was evaluated in an 8-week, double-blind, placebo-controlled study. Twenty-nine patients with mild essential hypertension were randomized to receive placebo (N = 9), 30 mg nifedipine (N = 10), or 60 mg nifedipine (N = 10). During treatment, 30-mg and 60-mg doses of nifedipine administered once daily decreased office blood pressures from 137/98 +/- 8/2 mm Hg and 141/98 +/- 15/2 mm Hg at baseline, respectively, to 126/89 +/- 9/7 mm Hg and 126/86 +/- 6/7 mm Hg (P less than .005). Noninvasive automatic ambulatory blood pressure monitoring demonstrated a marginally significant (P less than .10) reduction in the mean 24-hour blood pressure of 2/6 +/- 8/8 mm Hg and 5/6 +/- 9/9 mm Hg for patients taking 30 mg and 60 mg nifedipine once daily, respectively. Diastolic blood pressure load (the percentage of ambulatory diastolic blood pressure readings greater than 90 mm Hg) during 24 hours was decreased by 41% and 35%, with 30 mg and 60 mg nifedipine administered once daily, respectively. No significant dose response to nifedipine at these dose levels was observed. Although the once-daily formulation of nifedipine achieved effective control of office blood pressure, similar control was not observed in awake and 24-hour periods in all patients.
Asunto(s)
Presión Sanguínea/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Nifedipino/uso terapéutico , Adulto , Determinación de la Presión Sanguínea , Preparaciones de Acción Retardada , Método Doble Ciego , Femenino , Humanos , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Nifedipino/administración & dosificación , Nifedipino/efectos adversos , Factores de TiempoRESUMEN
This article has reviewed the involvement of the kidney as a target organ of essential hypertension. Since Bright first made the association of renal disease and hypertension in 1836, the nature of this relationship has been debated. Although there is evidence implicating abnormalities of renal function in the pathogenesis of essential hypertension, hypertension frequently precedes histologic evidence of alterations in renal structure. Nephrosclerosis, or hardening of the kidney, is the term used to describe the histologic changes occurring in the kidney as the result of hypertension. It can be though of as an acceleration of the normal aging process of the renal vasculature. Glomerular and tubular changes have been traditionally thought to be ischemic in origin. Experimental evidence supports the notion that, as renal function is lost, intraglomerular hypertension develops and may be responsible for additional nephron loss in hypertension. This idea may have therapeutic implications for hypertensive patients with renal insufficiency in that agents that reduce both systemic and intraglomerular pressure may be preferable. Hemodynamically, early hypertension is often characterized by normal peripheral and renal vascular resistance and an increased cardiac output. In established hypertension, cardiac output is usually normal, and peripheral and renal vascular resistances are increased. Renal blood flow is reduced, glomerular filtration rate is maintained, and the filtration fraction rises. In the absence of an accelerated malignant phase, renal failure is uncommon in essential hypertension. Males and blacks are most sensitive to the vascular damage of essential hypertension. Essential hypertension remains an important cause of end-stage renal disease, especially in blacks. Atherosclerotic obstruction of the renal arteries may be a more common cause of renal failure in patients with essential hypertension than has been previously recognized. There are few sensitive markers of early renal involvement in essential hypertension. Several studies of sensitive markers are promising and may detect patients who are prone to renal injury and deserve more aggressive treatment. Malignant hypertension is characterized pathologically by vascular changes of proliferative endarteritis and fibrinoid necrosis. Fortunately, its frequency is decreasing because of early identification and effective treatment of essential hypertension. Effective treatment of severe and malignant hypertension clearly leads to stabilization (and occasionally improvement) of renal function.(ABSTRACT TRUNCATED AT 400 WORDS)
Asunto(s)
Hemodinámica , Hipertensión Maligna/patología , Hipertensión/complicaciones , Fallo Renal Crónico/etiología , Nefroesclerosis/patología , Humanos , Fallo Renal Crónico/fisiopatología , Nefroesclerosis/metabolismo , Circulación RenalRESUMEN
Orthostatic hypotension has a number of causes, many of which are easily reversible. However, characteristics such as standing hypotension in conjunction with supine hypertension are not always easily detected in the clinic or office setting. Ambulatory blood pressure monitoring may be a valuable technique for diagnosis and for the assessment of therapeutic effects in patients with orthostatic hypotension.