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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diurnal patterns of blood pressure and pressor hormones after 26 weeks gestation were compared in 10 normotensive women, 13 subjects with uncomplicated hypertension, and 8 with biochemical evidence of pre-eclampsia. 4 of the pre-eclamptics showed nocturnal hypertension. Levels of plasma renin activity fell progressively from 9 a.m. to midnight in all three groups, and were significantly lower in pre-eclampsia. Plasma angiotensin II levels fell during the day in normotensives and uncomplicated hypertensives, whereas pre-eclamptics showed loss of this pattern and significantly lower levels than the other groups. Free plasma norepinephrine levels fell during the day and to a similar extent in all three groups. A diurnal pattern for free plasma norepinephrine levels, with lower levels at midnight than during the day, was seen in normotensives and uncomplicated hypertensives but not in pre-eclamptics. Plasma norepinephrine sulphate levels rose from 9.00 a.m. to midnight in normotensives and uncomplicated hypertensives. This pattern was reversed in pre-eclamptics, including 3 of the 4 subjects with nocturnal hypertension. Plasma epinephrine sulphate levels rose progressively through the day, with no significant differences between groups. Failure of plasma angiotensin II or epinephrine levels to fall at night in pre-eclampsia may contribute to nocturnal hypertension in subjects with increased vascular reactivity. Suppression of plasma renin activity and angiotensin II levels suggests that perhaps as yet unidentified pressor mechanisms are involved in pre-eclampsia.
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PMID:Diurnal rhythms of blood pressure, plasma renin activity, angiotensin II and catecholamines in normotensive and hypertensive pregnancies. 634 45

The anti-hypertensive effects of xipamide in doses of 5-20 mg once daily were studied in a multicenter study. Three general practitioners recruited 74 patients with uncomplicated hypertension. After a run-in period, patients entered a dose-ranging study and were followed for an average period of 10.4 months. Supine and standing blood pressures were significantly decreased (22.2/14 and 21/14 mmHg) during xipamide therapy with average daily dose of 12.2 mg. Serum potassium values dropped from 4.43 +/- 0.06 to 3.96 +/- 0.5 mEq/l, and serum uric acid increased from 5.47 +/- 0.06 to 6.04 +/- 0.18 mg%. In a second part 47 patients entered a double-blind, crossover study of placebo. Their optimum xipamide doses confirmed that in the majority of patients with mild to moderate hypertension xipamide in doses lower than 20 mg is effective in lowering blood pressure. The study further confirmed that xipamide exerted its anti-hypertensive effects for at least 24 h.
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PMID:Once daily administration of low-dose xipamide: a long-term study in mild to moderate hypertension. 635 42

Epidemiological data indicate a weak but significant positive correlation between the level of salt intake and blood pressure. It is unclear how this relationship is mediated but some studies indicate that heredity for hypertension is associated with an increased sensitivity to salt. Decrease of the salt intake decreases blood pressure in established hypertension and should be used as a therapeutic adjuvant in mild uncomplicated hypertension much more often than is now the case. Increased salt intake in young subjects with or without heredity for hypertension does not seem to increase the blood pressure during a 4-12 week load. Increased salt intake in middle-aged men, on the other hand, seem to induce a blood pressure increase irrespective of the presence or absence of a positive family history. The sensitivity to a high salt intake might thus be associated with aging. Increase of the salt intake from the normal level seems to induce an increase in sympathetic nervous activity. The interplay between the level of salt intake and sympathetic nervous activity should be studied in more detail.
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PMID:The role of salt in hypertension. 635

After screening a local population in the northern part of The Netherlands for hypertension, 119 patients with a diastolic pressure (DP) between 95 and 120 mmHg were randomised and treated either with 50 mg hydrochlorothiazide (n = 59) or 100 mg atenolol (n = 60). After 1 month of treatment 6 patients in the hydrochlorothiazide group and 24 patients in the atenolol group had reached a DP less than or equal to 90 mmHg (p less than 0.001). 43 of the 50 non-responders to hydrochlorothiazide were switched to atenolol and 30 of the 35 non-responders to atenolol were changed to hydrochlorothiazide. One month after the switch 19 patients in the atenolol group and 2 patients in the hydrochlorothiazide group had reached a DP less than or equal to 90 mmHg (p less than 0.001). After 6 months of treatment 32 of the 43 atenolol responders and 7 of the 8 hydrochlorothiazide responders were still receiving the same medication, as their DP was still less than or equal to 90 mmHg. Non-responders to either medication were given the combination (n = 46). 21 patients now became normotensive as did a further 10 after increasing the dose of atenolol to 200 mg. Thus, in all 70 patients had a blood pressure less than or equal to 90 mmHg after treatment for 4 months. Both drugs induced a significant reduction in the total of number of complaints after 1 month of treatment. They did not differ from each other. The reduction was seen both in responders and non-responders and persisted during treatment for 6 months. It is concluded that in terms of short-term efficacy the cardioselective, hydrophilic beta adrenoceptor-blocking drug atenolol is preferable to hydrochlorothiazide in the treatment of uncomplicated hypertension.
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PMID:Comparison of hydrochlorothiazide and atenolol as initial treatment in uncomplicated hypertension. 637 3

The effect of long-term treatment with nitrendipine on systemic pressor responses to norepinephrine (NE) and angiotensin II (AII) was evaluated in 11 subjects with mild, uncomplicated hypertension. Pressor responses to NE and AII were measured at the end of a 4-wk placebo period and after 5 wk treatment with nitrendipine (final dose 16 mg twice daily; range 5 to 20 mg/day) or placebo. In subjects who received nitrendipine, clinic supine blood pressure was reduced from 152 +/- 12/96 +/- 4 mm Hg to 134 +/- 11/84 +/- 5 mm Hg and pressor responses to NE but not to AII were attenuated. Endogenous plasma levels of NE and renin activity were not changed by nitrendipine. Data suggest that noradrenergic blood pressure control mechanisms depend more on cellular calcium transport than do AII-mediated ones and may help explain the greater effectiveness of calcium entry blockers in the treatment of low-renin hypertension.
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PMID:Altered pressor responses in long-term nitrendipine treatment. 638 Aug 80

To analyze changes in left ventricular diastolic properties in hypertensive heart disease, the atrial emptying index was used to assess the rapid phase of diastolic filling of the left ventricle. Ten normal subjects (Group 1), 11 hypertensive patients without evidence of cardiac involvement (Group 2) and 10 hypertensive patients with echocardiographic evidence of left ventricular hypertrophy (Group 3) were compared using M mode echocardiography and systemic hemodynamic data. Whereas cardiac index (dye-dilution method) and rate of circumferential fiber shortening (echocardiogram) were normal in all three groups, there was a progressive increase in left atrial index (p less than 0.001, Group 1 versus Group 2 and versus Group 3) and a progressive decrease in the atrial emptying index (p less than 0.001, Group 1 versus Group 2 and versus Group 3). No correlation existed between the atrial emptying index and the left atrial index, mean arterial pressure or total peripheral resistance in any of the three groups. These data suggest that rapid filling of the left ventricle is reduced early in hypertension, even before electrocardiographic or systolic echocardiographic abnormalities are detectable. The atrial emptying index therefore appears to be an early indicator of abnormalities of left ventricular diastolic compliance in uncomplicated hypertension.
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PMID:Echocardiographic diastolic ventricular abnormality in hypertensive heart disease: atrial emptying index. 645 11

The pathophysiologic significance of increased serum and urinary N-acetyl-beta-D-glucosaminidase (NAG) activity in hypertension was investigated. The subjects were 32 male patients, aged 40-65 years, with mild or borderline, uncomplicated hypertension and 26 age-matched, male normotensive volunteers. Compared to values in control subjects, NAG activity in the serum, spot and 24-hour urine samples of hypertensive subjects was increased (p less than 0.01). Serum NAG activity in hypertensive subjects was inversely correlated with glomerular filtration rate (r = -0.49, p less than 0.01, N = 31) and renal plasma flow (r = -0.56, p less than 0.02, N = 19) and positively correlated with mean arterial blood pressure (r = 0.40, p less than 0.05). The elevation of serum NAG activity in hypertension is a biochemical marker of the reduction in glomerular filtration rate and renal plasma flow.
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PMID:Increased serum and urinary N-acetyl-beta-D-glucosaminidase activity in human hypertension: early indicator of renal dysfunction. 672 92

Effective diuresis requires both sufficient glomerular filtrate and adequate delivery of the diuretic drug to the lumen of the renal tubule. Diuretics will not "force open" the kidney. Diuretics that work primarily in the proximal tubule include osmotic diuretics (e.g., mannitol), diuretics that interfere with the adenyl cyclase system (e.g., xanthines), and those which inhibit carbonic anhydrase (e.g., acetazolamide). Some thiazide and thiazide-like diuretics have a secondary site of action in the proximal tubule based on either carbonic anhydrase inhibition or other mechanisms, such as inhibition of sodium phosphate reabsorption. The diuretics that work primarily in the medullary diluting segment of the loop of Henle, furosemide and ethacrynic acid, block the active reabsorption of chloride and interfere with the tubular reabsorption of free water. The exact mechanism remains unknown. These diuretics tend to have a "high ceiling," to be potent and rapidly acting, and to have a short duration of effect. They are excellent for the treatment of severe fluid overload or pulmonary edema but are not ideal for the treatment of uncomplicated hypertension. Furosemide is a sulfonamide derivative; ethacrynic acid can be used in patients who are allergic to sulfa drugs. Diuretics that work primarily in the cortical diluting segment include the thiazides and thiazide-like drugs. They inhibit sodium transport by an undetermined mechanism. Most of them seem to reach a dose-response plateau beyond which little additional effect is gained by increasing the dose. Most of them appear to lose efficacy as the glomerular filtration rate decreases, except for metolazone and indapamide. The thiazides are most commonly used to treat hypertension. Diuretics that work primarily in the distal tubule and collecting tubule include the aldosterone inhibitor spironolactone and two drugs that impair tubular reabsorption of sodium by direct action, triamterene and amiloride. These drugs are primarily used for their potassium-sparing effect.
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PMID:Insights into intrarenal sites and mechanisms of action of diuretic agents. 686 1

In a randomized cross-over trial the combination labetalol/hydrochlorothiazide was compared with the combination of propranolol/hydralazine/hydrochlorothiazide in 34 uncomplicated hypertensive patients, who were not satisfactorily controlled with hydrochlorothiazide 50 mg alone. The elevated diastolic pressure (D.P.) in 27 patients responded satisfactorily to the labetalol schedule and in 28 patients to the propranolol/hydralazine schedule. No difference was found in the rate of decrease of D.P., nor in the disappearance of hypertension-related complaints. Although the duration of the washout between treatments was at least one month, treatment was significantly more efficacious during the second period. Labetalol pre-treatment especially seemed to enhance the effect of subsequent propranolol/hydralazine administration. Side effects due to therapy were rare and were not related to any particular treatment. The median daily dose of labetalol in responders was 600 mg and that of propranolol/hydralazine 120/60 mg (in both therapies hydrochlorothiazide 50 mg was given in addition). Patients showed a slight preference for the labetalol medication. It is concluded that labetalol/hydrochlorothiazide and propranolol/hydralazine/hydrochlorothiazide are equally satisfactory in the treatment of uncomplicated hypertension.
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PMID:Comparison of labetalol, propranolol and hydralazine in hypertensive out-patients. 704 73

Ambulatory intra-arterial blood pressure monitoring was used to record blood pressure during graded exercise on a bicycle ergometer and during stair climbing in 6 normotensive subjects, 19 patients with untreated uncomplicated hypertension and 8 patients with untreated hypertension and ECG evidence of left ventricular hypertrophy. Exercise was performed on the bicycle ergometer at 250, 400, 700 and 1,000 kpm/min and each subject also climbed a maximum of 160 stairs. Bicycle ergometry was associated with an increase in systolic and diastolic blood pressure, and in patients with uncomplicated hypertension the levels of pressure attained were high. Stair climbing produced an increase limited mainly to systolic blood pressure, and in some subjects was followed by a secondary increase in both systolic and diastolic pressure during the recovery period. The blood pressure response to bicycle ergometry and stair climbing was generally similar in normotensive and hypertensive subjects but the increase in pressure was greatest in the patients with uncomplicated hypertension.
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PMID:Continuous recording of intra-arterial blood pressure during graded bicycle ergometry and stair climbing in essential hypertension. 729 20


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