摘要:

A multicenter, randomized double-blind study of 6 months' duration was performed in 540 patients (average age 54 years, 57% male) with mild-to-moderate essential hypertension to determine the relative effects on quality of life of cilazapril, atenolol, and nifedipine retard. Quality of life was assessed by using both a self-administered and an interviewer-administered questionnaire; the assessment included a complaint score (symptoms checklist), Health Status Index, assessment of work satisfaction, Psychological General Well-being Index, Profile of Mood States subscales, and life satisfaction assessment Psychomotor function was measured by the Reitan Trail Making test B. At the end of the trial, diastolic blood pressure had fallen by an average of 15 mm Hg in all three groups, but significantly (p=0.01) more patients taking cilazapril required the addition of a diuretic (36%) compared with those taking atenolol (25%) or nifedipine retard (24%). No significant differences in quality of life were observed between cilazapril and atenolol during the trial. Symptomatic complaints increased on nifedipine retard (p=0.02) and contributed to a higher discontinuation rate (21% discontinued treatment compared with 13% and 14% taking atenolol and cilazapril, respectively,p=0.04). However, a possible improvement in the fatigue subscale (p=0.04) was also observed on nifedipine retard. The 95% confidence intervals showed that none of the drugs in this trial produced an effect equivalent to that previously reported between captopril and methyldopa in the Psychological General Well Being Index or between captopril and methyldopa or propranolol in Trail Making test B. We conclude that cilazapril and atenolol have equivalent effects on quality of life, but nifedipine retard was associated with more symptomatic complaints and a higher discontinuation rate.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The purpose of the present study was to assess the prevalence of orthostatic hypotension and its associations with demographic characteristics, cardiovascular risk factors and symptomatology, prevalent cardiovascular disease, and selected clinical measurements in the Cardiovascular Health Study, a multicenter, observational, longitudinal study enrolling 5, 201 men and women aged 65 years and older at initial examination. Blood pressure measurements were obtained with the subjects in a supine position and after they had been standing for 3 minutes. The prevalence of asymptomatic orthostatic hypotension, defined as 20 mm Hg or greater decrease in systolic or 10 mm Hg or greater decrease in diastolic blood pressure, was 16.2%. This prevalence increased to 18.2% when the definition also included those in whom the procedure was aborted due to dizziness upon standing. The prevalence was higher at successive ages. Orthostatic hypotension was associated significantly with difficulty walking (odds ratio, 1.23; 95% confidence interval, 1.02, 1.46), frequent falls (odds ratio, 1.52; confidence interval, 1.04, 2.22), and histories of myocardial infarction (odds ratio, 1.24; confidence interval, 1.02, 130) and transient ischemic attacks (odds ratio, 1.68; confidence interval, 1.12, 2.51). History of stroke, angina pectoris, and diabetes mellitus were not associated significantly with orthostatic hypotension. In addition, orthostatic hypotension was associated with isolated systolic hypertension (odds ratio, 135; confidence interval, 1.09, 1.68), major electrocardiographic abnormalities (odds ratio, 1.21; confidence interval, 1.03, 1.42), and the presence of carotid artery stenosis based on ultrasonography (odds ratio, 1.67; confidence interval, 1.23, 2.26). Orthostatic hypotension was negatively associated with weight. We conclude that orthostatic hypotension is common in the elderly and increases with advancing age. It is associated with cardiovascular disease, particularly those manifestations measured objectively, such as carotid stenosis. It is associated also with general neurological symptoms, but this link may not be causal. Differences in prevalence of and associations with orthostatic hypotension in the present study compared with others are largely attributed to differences in population characteristics and methodology.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Central obesity increases the risk for cardiovascular disease, but little is known about its hemodynamic effects. The aims were to investigate the influence of obesity (as defined by body mass index) and abdominal fat accumulation (as defined by the waist/hip ratio) on hemodynamics at rest and during mental stress. Invasive hemodynamic studies were performed in 20 healthy, normotensive young men (aged 18–22 years) recruited from an unbiased population sample. Their body mass index and waist/hip ratio ranged between 18.5 and 30.2 (mean 24.1) and 0.77 and 0.98 (mean 0.87), respectively. Hemodynamics were related to the two anthropometric indexes by bivariate regression analyses. Cardiac output and stroke volume were positively correlated to body mass index (p=0.05 andp=0.005), but inversely to waist/hip ratio (p=0.01 andp=0.01). Mental stress augmented the hemodynamic patterns. Total peripheral resistance during stress correlated inversely to body mass index (p=0.02), whereas high waist/hip ratio was associated with higher systemic vascular resistance (p=0.002). The ΔCO/ΔMAP ratio, i.e., relative contribution of cardiac output for the stress-induced increase in mean arterial pressure, showed a strong positive association with body mass index (p=0.004), but was Inversely related to the waist/hip ratio (p=0.002). Serum insulin correlated significantly to the stress-induced change in total peripheral resistance (r=0.54;p=0.02), whereas the increase in cardiac output was inversely related to insulin (r=−0.59;p=0.007). Thus, central obesity is associated with a specific hemodynamic pattern characterized by higher total peripheral resistance, lower cardiac output, and a vasoconstrictor response to psychosocial stress.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

To assess a possible heritability of a disturbed calcium metabolism in relation to blood pressure regulation, 28 young normotensive offspring of either hypertensive or normotensive parents were studied while administered a denned diet with daily sodium chloride of 6 and 20 g/day for 7 days each. Before the high salt diet was begun, the cytosolic calcium concentration ([Ca2+]1) in platelets was elevated in offspring of hypertensive parents, whereas serum electrolytes, plasma renin activity, plasma catecholamines, and 24-hour urinary excretion of sodium and calcium showed no difference between the two groups. On exposure to a high salt diet, the mean blood pressure increased (from 80±2 to 85±2 mm Hg,p<0.05) in offspring of hypertensive parents. These changes in mean blood pressure were positively correlated with the basal platelet [Ca2+]1(r=0.61,p<0.01), whereas [Ca2+]1did not demonstrate any significant changes. When the subjects were administered the high salt diet, plasma ionized calcium decreased (from 2J7 to 2.21 meq/1,p<0.05) and 1, 25 -dihydroxy vitamin D3 increased (from 32.7 to 40.8 pg/ml,p<0.05) with a transient relative hypercalciuria in offspring of hypertensive parents. This increase of 1, 25 -dihydroxyvitamin D3 was significantly correlated with the changes in mean blood pressure (r=0.62,p<0.01). Disturbed intraplatelet and systemic calcium metabolism may be of predictive value in the development of hypertension.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The effects on blood pressure and the development of cardiac hypertrophy of sodium chloride (regular salt) and a novel potassium-, magnesium-, and I-lysine-enriched salt alternative, which in a previous study prolonged the life span of hypertensive rats nearly threefold as compared with the animals receiving regular salt, were compared both in spontaneously hypertensive rats and their hypertension-resistant genetic controls. In particular, the possible protective effect of increased intakes of potassium, magnesium, and I-lysine during a high intake of sodium chloride was examined. Therefore, the salt alternative was added at 1.75 times higher levels to produce the same dietary levels of sodium chloride in the regular salt and the salt alternative groups. Regular salt produced a remarkable left ventricular hypertrophy in both rat strains, but as compared with the respective control groups, it induced an increase of blood pressure only in the spontaneously hypertensive rats. The salt alternative did not induce a rise in blood pressure in either of the rat strains, nor did it produce left ventricular hypertrophy in the hypertensionresistant rats and, in the spontaneously hypertensive animals, significantly less hypertrophy than regular salt The salt alternative appeared to prevent the sodium chloride-induced volume load since plasma levels of atrial natriuretic peptide were increased in the regular salt groups but remained normal in the salt alternative groups. Therefore, potassium, magnesium, and/or I-lysine of the salt alternative produced a powerful protection against the harmful effects of sodium chloride.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Blood pressure in patients with essential hypertension is raised by sodium chloride but not by nonchloride sodium salts. Although a high sodium chloride diet is known to augment the pressor response to norepinephrine and angiotensin II, the effect of nonchloride sodium salts on pressor responsiveness has not been studied so far. To examine whether sodium chloride and nonchloride sodium salts evoke different pressor responses to these agonists, we performed graded norepinephrine and angiotensin II infusions in salt-sensitive (n=7) and salt-resistant (n=8) normotensive subjects. The subjects were given a low salt diet (20 mmol/day) for 3 weeks, to which a supplement of 200 mmol sodium per day, provided as either sodium chloride or sodium citrate, or a placebo was added for 1 week each. We found that, although sodium chloride raised mean arterial blood pressure in the salt-sensitive subjects (p<0.005), sodium citrate did not However, under both sodium salts pressor response to norepinephrine and angiotensin II was significantly greater than under placebo (p<0.02). Furthermore, with both sodium salts, pressor response in the salt-sensitive subjects was greater than in the salt-resistant subjects (p<0.01). This study thus demonstrates that, although blood pressure in salt-sensitive individuals is raised by sodium chloride only, both sodium chloride and sodium citrate evoke similar increases in pressor response to norepinephrine and angiotensin H. Since pressor response increased with both sodium salts but resting blood pressure increased only with sodium chloride, enhanced pressor responsiveness alone cannot account for the sodium chloride-induced rise in resting blood pressure.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The effect of salt intake on the hypertensive response to long-term infusion of endothelin-1 was investigated. Chronically instrumented male Sprague-Dawley rats (325–375 g) were used in a 15-day protocol that included 3 control days followed by 7 days of endothelin-1 infusion at 5.0 pmol · kg−1· min−1and 5 days of recovery. Rats were maintained on either a normal sodium chloride intake (2.0 meq Na+per day; normal sodium) or a high sodium chloride Intake (6.0 meq Na+per day; high sodium) throughout the protocol. Control rats received normal or high sodium intakes but not endothelin-1. In high-sodium rats, endothelin-1 produced a significant increase in mean arterial pressure and total peripheral resistance; a significant bradycardia was observed only on the first day after the start of the endothelin-1 infusion. Cardiac output, stroke volume, water balance, and urinary sodium and potassium excretion remained unchanged. Termination of endothelin-1 infusion resulted in rapid normalization of both arterial pressure and peripheral resistance. In contrast, normal sodium rats exhibited no alteration in mean arterial pressure, heart rate, total peripheral resistance, stroke volume, water balance, or urinary sodium and potassium excretion throughout the endothelin-1 infusion protocol. The hypertension produced by endothelin-1 infusion cannot be explained by alterations in salt or water balance since endothelin-1 infusion in high sodium animals produced significant increases in mean arterial pressure with no observable changes in water or electrolyte balance. These results indicate that endothelin-induced hypertension in conscious rats is a salt-dependent model of hypertension.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

An association between chronic high blood pressure and obstructive sleep apnea has been described. We hypothesized that repetitive episodic hypoxia patterned after the hypoxia seen in sleep apnea could contribute to diurnal elevation of blood pressure. Using 12-second infusions of nitrogen into daytime sleeping chambers, four groups of male rats (250–375 g) were subjected to intermittent hypoxia (3–5% nadir ambient oxygen) every 30 seconds, 7 hours per day for up to 35 days. In one group, blood pressure was measured weekly by the tail-cuff method in conscious animals during 5 weeks of episodic hypoxia. In the other three groups, blood pressure was measured in conscious animals via femoral artery catheters at baseline and after 20, 30, or 35 days of exposure. Additional groups served as controls: two sham groups housed in identical “hypoxia” chambers received compressed air instead of nitrogen (35 days) while two other groups remained unhandled in their usual cages (35 days). Both groups challenged with 35 days episodic hypoxia showed significant increases in blood pressure compared with controls: the tail-cuff rats showed a 21 mm Hg increase in systolic pressure (p<0.05) and the intra-arterially measured rats a 13.7 mm Hg increase in mean arterial pressure (p<0.05). The 30-day exposed rats also showed a 5.7 mm Hg increase in mean pressure over baseline (p<0.05). Blood pressure did not change significantly from baseline in the control groups. Left ventricle-to-body weight ratio was higher in both 35-day exposed groups than in unhandled or sham controls. This duration-of-exposure-related blood pressure response to hypoxia along with increased left ventricular size after 35 days indicates that chronic intermittent hypoxia could be a mechanism directly contributing to diurnal arterial blood pressure elevation.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

In previous studies short-term cortlsol increased cold pressor responses and the rise in forearm vascular resistance accompanying intra-arterial norepinephrine without an increase in overall resting sympathetic nervous activity. The present study examined whether these alterations in pressor response are glucocorticold or mineralocorticoid effects, or both. Normal male subjects (n= 12) received either fludrocortisone, 03 mg daily (n=6), or dexamethasone, 3 mg daily (n=6), for 7 days. Hemodynamic studies were performed before and on day 7 of treatment Fludrocortisone increased body weight from 69.3±1.8 to 71.1±2 kg (p<0.001), cardiac output from 5.0 to 6.0 1/min (±0.1,p<0.01), mean arterial pressure from 82±1 to 91±1 mm Hg (p<0.001), cold pressor responsiveness from 13.0 to 39.0 mm Hg/ml per 100 ml per minute (R units)(±4.3,p<0.01), and forearm vascular response to intra-arterial norepinephrine (F=59.4,p<0.01) and angiotensin II (F=30.8,p<0.01) infusions. Total peripheral resistance fell from 22.0 to 20.1 mm Hg/1 per minute (±03,p<0.05). Dexamethasone did not increase cardiac output, 5.1 to 5.2 l/min (±0.1), or body weight but did increase mean arterial pressure from 82±3 to 91 ±3 mm Hg (p<0.001), cold pressor responsiveness from 8.6 to 17.1 R units (±2.8,p<0.05), and forearm vascular response to Intra-arterial norepinephrine (F=33.0,p<0.01) and angiotensin II (F=54.9,p<0.01). Total peripheral resistance increased from 21.9 to 24.3 mm Hg/1 per minute (±0.4,p<0.01). Thus, short-term fludrocortisone and dexamethasone produced similar rises in pressure: fludrocortisone with an increase in cardiac output and dexamethasone with an increase in resistance. Although hemodynamic patterns differ, increased pressor responsiveness is a feature of both mineralocorticoid and glucocorticoid administration in humans.

ISSN:0194-911X    

出版商:OVID    

年代:1992

数据来源: OVID