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

Diurnal 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) pattern was studied with RIA technique in 33 hypertensive patients in supine position and on normal sodium diet. The compound was evaluated every 2 h from 0800-2000 h. Simultaneously, plasma aldosterone and cortisol were measured. Abnormal 18-OH-DOC behavior was observed in only 2 out of 4 patients with Cushing's disease, while sporadic and slight elevations, synchronous with F, were seen in 5 out of 24 stable essential hypertensive patients [1 with normal plasma renin activity (PRA), 1 with low PRA, and 3 with high PRA]. 18-OH-DOC was normal in 2 cases of hypertension due to renal artery stenosis, in 1 patient with nephrosclerosis, and in 1 patient with horseshoe kidney. From these results, 18-OH-DOC does not seem to play an important pathogenetic role in stable essential hypertension, considering also the low mineralocorticoid activity of the compound.
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PMID:Diurnal 18-hydroxy-11-deoxycorticosterone pattern in human stable hypertension. 40 Jul 33

1. The 24 h urinary excretion of adrenaline, noradrenaline, normetadrenaline, metadrenaline and vanilloylmandelic acid has been compared in 17 male normotensive subjects and 25 age-matched male hypertensive patients studied under similar in-patient conditions. 2. 24 h urinary metadrenaline was significantly lower in the hypertensive patients. With this exception, no significant differences were found between the two groups when the total 24 h excretion of free catecholamines and their metabolites was analysed. 3. Diurnal variation in free catecholamine excretion was found in both normotensive and hypertensive subjects. There was no corresponding variation in metabolite excretion. 4. No correlation could be established between systolic or diastolic blood pressure and the amounts of the catecholamines or their metabolites in the urine of either group. 5. The results are considered in the light of recent work demonstrating high plasma catecholamine concentrations in hypertension. They lend no support to the concept that excessive circulating catecholamines are responsible for the elevated blood pressure in essential hypertension.
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PMID:The urinary excretion of catecholamines and their derivatives in primary hypertension in man. 55 4

Diurnal change of plasma atrial natriuretic peptide (ANP) concentration was investigated in 12 patients with hypertension due to chronic renal failure (CRF) and in 12 patients with essential hypertension (EH) of comparable degree. Blood pressure (BP) monitoring was performed at 15-min intervals, while peripheral blood samples were obtained at 4-hour intervals starting from 8.00 h. The mean 24-hour plasma levels (+/- SEM) of ANP were 24.3 +/- 1.8 pmol/l in EH and 23.4 +/- 1.2 pmol/l in CRF. In EH, plasma ANP concentration was highest at 4.00 h (33.5 +/- 0.8 pmol/l) and lowest at 16.00 h (15.5 +/- 0.6 pmol/l). In CRF, no significant circadian change was present (22.2 +/- 3.1 and 20.4 +/- 3.6 pmol/l, respectively), and the nocturnal fall in BP was lost. Our data demonstrate that in CRF the loss and possible reversal of the nocturnal decline in BP is associated with the disappearance of any significant circadian variation in the circulating concentrations of ANP. These findings suggest a role for ANP in the alteration of BP variability of CRF, possibly mediated by autonomic dysfunction, and are further evidence for the existence of a relation between the circadian rhythms of ANP and BP.
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PMID:Loss of nocturnal increase in plasma concentration of atrial natriuretic peptide in hypertensive chronic renal failure. 145 Nov 18

In 40 subjects (23 treated with antihypertensive medication), 24-h ambulatory blood pressure was measured with an oscillometric blood pressure monitor (Spacelabs model 90202). We studied applicability in the out-patient department with regard to patient tolerance, correlation with mercury manometer measurements, 24-h blood pressure variability and the use in detecting "white-coat" hypertension. The measurements were tolerated quite well except for complaints of sleep disturbance and local irritation from the cuff. The average percentage of missed measuring points was 9.2%. Correlation between blood pressure with the mercury manometer and the Spacelabs monitor (averages of three consecutive readings) was: systolic 0.87 and diastolic 0.73 (P less than 0.001). No evidence for systematic error between the two methods was found. Diurnal blood pressure variation was significant with an average night-time drop of 12 +/- 15 mmHg systolic and 12 +/- 11 mmHg diastolic. "Office" blood pressure measured with the Spacelabs monitor was in the hypertensive range for 28 patients (systolic greater than or equal to 160 and/or diastolic greater than or equal to 95 mmHg). Only 15 of these subjects still met the hypertension criteria on the basis of mean daytime ambulatory blood pressure values. When ambulatory blood pressures during arbitrary 3-h periods of the daytime were studied, the number of patients with established hypertension did not change. The patients with this "office" or "white-coat" hypertensive response could not be distinguished on the basis of variability in daytime blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Experience with noninvasive ambulatory 24-hour blood pressure recording in a community hospital. 160 8

The purpose of the study was to evaluate the interest of ambulatory blood pressure (BP) recording (ABPR) in the management of arterial hypertension (AH) with dysautonomia. The study concerned 8 hypertensive patients (pts), 5 men, 3 females 52 +/- 10 years old, with orthostatic hypotension (OH): BP was 162 +/- 19/87 +/- 16 mmHg and 129 +/- 15/76 +/- 8 mmHg in lying and standing position respectively. In two cases AH was associated with a central degenerative disorder whereas the six other pts had a diabetic dysautonomia: bad metabolic control (HBA1c 14.4 +/- 2.7%), and incipient or over nephropathy (4 pts). ABPR was performed in all pts during 24 hours (space-labs system). In these hypertensive pts with OH, the mean 24 hour-BP was surprisingly normal at 128 +/- 11/76 +/- 6 mmHg. ABPR demonstrated the loss of nocturnal decline in BP: diurnal and nocturnal BP were respectively 125 +/- 13/74 +/- 6 mmHg and 133 +/- 16/78 +/- 10 mmHg (NS). 6 of 8 pts had an increase in BP at night resulting for the population (n = 8) in a nocturnal increase (%) of + 5.6%, this pattern widely differs from controls--13%. The decrease in heart rate during sleep was blunted but significant from 89 +/- 9 b/min to 81 +/- 9 b/min (p 0.01). Diurnal and nocturnal BP variability (V), assessed by variation coefficient were not significantly different: SBP-V was 10.3 +/- 6.4% day and 12.3 +/- 4.2% night, DBP-V 7.5 +/- 6.3% day and 12.5 +/- 3.1% night.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Ambulatory blood pressure in hypertension with dysautonomia]. 212 48

Obstructive apnea (asphyxia) is accompanied by acute elevation of systemic blood pressure. The usual nocturnal fall in blood pressure seen during sleep in normals may be absent in patients with repetitive apneas, and daytime systemic hypertension is reported to occur in up to 90% of such patients. Increased sympathetic activity in response to repetitive nocturnal episodes of asphyxia could explain the reversal of the diurnal pressure variation but not the daytime systemic hypertension in this setting. We examined diurnal variation in urinary catecholamines in eight subjects with severe apnea before and after tracheostomy. Five obese hypertensive subjects without apnea served as controls. Three urine specimens, two awake (7 a.m. to 3 p.m. and 3 p.m. to 11 p.m.) and one asleep (11 p.m. to 7 a.m.) were collected preoperatively and again 10-14 days postoperatively when the patient was free of pain and signs of stoma infection. All specimens were analyzed for epinephrine, norepineprine, metanephrine, and normetanephrine by liquid chromatography with electrochemical detection. Urinary epinephrine and metanephrine were not different between subjects and controls. Norepinephrine and normetanephrine were significantly higher in apneic subjects pretracheostomy as compared either with controls or with their own values posttracheostomy. Diurnal variation was not seen before or after tracheostomy. Only two of the controls showed significant diurnal variation in norepinephrine. We conclude that the absence of diurnal variation in catecholamines prior to tracheostomy reflects increased nocturnal sympathetic activity. Elevation of daytime norepinephrine and normetanephrine with return to control levels following tracheostomy implies increased sympathetic activity throughout the day.
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PMID:Urinary catecholamines before and after tracheostomy in patients with obstructive sleep apnea and hypertension. 356 46

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 state of the renal prostaglandins (PG) system was assessed in 54 patients with essential hypertension, stage IB-IIA, as compared to that of patients with symptomatic arterial hypertensions. A decrease in renal PGE2 production, noted in all hypertensive patients and determined on the basis of its diurnal excretion, was particularly pronounced in essential hypertension. Diurnal PGE2 excretion decreased as hypertension progressed in patients with essential hypertension, and renal PGF2 alpha production became prevalent. Renal function is dependent on the level of PG production by the kidney. As renal concentration capacity decreases and renographic findings become less satisfactory, PGE2 excretion decreases as well. Salt loads can bring out functional insufficiency of the renal PG system in essential hypertension, as reflected in a much smaller increase in PGE2 excretion, as compared to the control values, at early stages of salt loading and a considerable increase in PGF2 alpha excretion. In essential hypertension, inadequate renal prostaglandin response to salt loading is, to a certain degree, related to changed renal PGE-9-ketoreductase activity.
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PMID:[Status of the humoral system of renal prostaglandins in patients with hypertension]. 658 45

Diurnal variations of the basal blood pressure in patients with essential hypertension were investigated by the indirect recording methods. To estimate the reduction in blood pressure at midnight, disturbance of sleep in the patients should be considered. Relationship between neurohumoral factors and the diurnal blood pressure variations were also evaluated. 1) Variations of the casual blood pressure at the clinic visits may be stabilized beyond 15 minutes of the sitting rest. 2) During the out-patient treatment of essential hypertension with placebo for 6 weeks, 16% of the patients showed reduction in mean arterial pressure of 13 mmHg or more. 3) Significant influence of seasons on blood pressure was not apparent for 6 weeks of the placebo treatment of hypertension. But in patients under the long-term antihypertensive treatment, blood pressure in summer was maintained significantly lower than in winter. 4) Self-monitoring of blood pressure by patients at home is valuable for estimating diurnal changes of blood pressure with the antihypertensive treatment.
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PMID:Blood pressure variations to be considered in the treatment of hypertension. 719 67

PATHOPHYSIOLOGY OF HYPERTENSION: Blood pressure increases with advancing age in most developed countries. The pathophysiology of elderly hypertension is characterized by changes in the structure and function of the cardiovascular system. Changes in arterial structure lead to a decrease in aortic compliance, which augments the aortic pressure component generated by the wave reflection mechanism. The age-related increase in the reflected-wave component of arterial pressure may contribute, at least in part, to the age-related rise in systolic blood pressure. Disproportionately elevated systolic blood pressure in the elderly may account for the progressive increase in left ventricular mass with advancing age. In addition to the changes in vascular and cardiac structures, the haemodynamic function of elderly hypertensives is characterized by increased peripheral resistance as well as reduced cardiac output, renal blood flow and intravascular volume. In contrast to younger hypertensives, the sympathetic and renin-angiotensin systems may not be major factors in the genesis of high peripheral resistance in this patient group. END-ORGAN DAMAGE: The most important end-organ damage in elderly hypertensives is left ventricular hypertrophy with or without coronary heart disease, cerebrovascular disease or renal impairment. Furthermore, this end-organ damage is frequently asymptomatic (silent). The prevalence of silent cerebrovascular disease in particular is surprisingly high in this elderly population. Asymptomatic cerebrovascular disease has been shown to be associated with various cardiovascular risk factors, and depressed neurobehavioural function. Diurnal blood pressure variations appear to be related to end-organ damage. The presence of occult end-organ damage and co-existing diseases common in elderly hypertensives has important clinical implications in the management of this disorder.
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PMID:Pathophysiology and end-organ damage in elderly hypertensives. 779 9


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