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

The aim of this prospective, randomized, double-blind, placebo controlled study was to investigate the effect of nifedipine on carbohydrate metabolism in diabetic patients after a 3-day and a 3-month course of treatment. Sixteen non obese, well controlled non-insulin dependent diabetics, (HbA1 less than 10%), with moderate untreated hypertension were divided in two groups: nifedipine (group N, 8 patients) and placebo (group P, 8 patients). An oral glucose tolerance test (OGTT, 75 g glucose) and an arginine infusion were performed before, after a 3-day, and a 3-month course, either of nifedipine 30 mg/D or placebo. Blood samples obtained during OGTT were assayed for glucose and insulin, and during arginine infusion for insulin, glucagon and growth hormone. The differences between basal and peak values during tests were compared between both groups before and after treatment using Wilcoxon's rank sum test. Neither acute nor chronic administration of nifedipine or placebo modified the glucose tolerance. However, basal insulin levels were reduced by 3 month-administration of nifedipine (from 19 +/- 2 micromicrons/ml to 10 +/- 1 micromicrons/ml, p = 0,01). Otherwise the basal and peak hormonal values during tests were not significantly affected by nifedipine either at the start of after 3 months of treatment. These results suggest that nifedipine, when given in standard dosage for 3 months, has minor effects on carbohydrate metabolism in non-insulin dependent diabetic patients.
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PMID:[Effects of nifedipine on carbohydrate metabolism in the non-insulin dependent diabetic]. 389 85

Forty percent of patients with insulin-dependent diabetes will develop nephropathy during the course of their disease, thus being the most important single disorder leading to end-stage renal failure (ESRF). Intensive metabolic control delays onset of diabetic nephropathy, the first omen of which is appearance of subclinical albuminuria, also termed microalbuminuria. Moreover, it is now established that intensive treatment of hypertension reduces rate of decline in GFR and thus postpones ESRF. When uremia eventually sets in, a range of biochemical and endocrine abnormalities can be included among those characteristics of diabetes mellitus per se. These include elevated plasma levels of growth hormone, glucagon and free fatty acids, which may participate in the uremic insulin resistance superimposed on the preexisting diabetic carbohydrate intolerance. Hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) are two established modalities of renal replacement therapy in diabetes mellitus. Controlled clinical trials for comparison of CAPD versus HD treatment of diabetics are, however, still needed. The survival rate is approximately 80 and 65-95% in insulin-dependent diabetic patients at 1 year during treatment with HD and CAPD, respectively. However, it is general experience that diabetics on CAPD exhibit a glycemic control, superior to that attained during HD. It has not been proved that patient survival after cadaveric renal transplantation is better than on dialysis. The degree of vascular heart disease seems to be the major determinant for survival of kidney-transplanted diabetic patients.
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PMID:End-state renal failure in diabetic nephropathy: pathophysiology and treatment. 391 47

Cardiovascular complications are a major cause of morbidity and mortality in acromegaly and seem to be related to the long duration of the disorder. Conventional external pituitary irradiation for acromegaly produces a consistent, but slow, fall in elevated serum growth hormone (GH) levels. It has not been established whether such treatment is effective in preventing the development of cardiovascular complications. The evolution of cardiovascular disease has therefore been studied in 11 acromegalic patients followed up for a mean 10 years (range 3-17) after external pituitary irradiation. At the final follow-up fasting serum GH were significantly (P less than 0.01) lower than pre-irradiation levels, but cardiovascular events (myocardial infarction, dysrhythmias, hypertension, major arterial disease, heart failure) increased significantly in prevalence (P less than 0.01) during this period. Electrocardiographic abnormalities also increased in prevalence. At the final follow-up 6 patients had cardiomegaly on chest X-ray and echocardiographs (10 patients) were abnormal in every case. All 11 patients had evidence of complete or partial anterior hypopituitarism. We confirm that external pituitary irradiation is effective in reducing elevated serum GH levels in acromegaly, but suggest that such a slow reduction in serum GH levels does not retard the development of cardiovascular complications.
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PMID:Progression of cardiovascular disease in acromegalic patients treated by external pituitary irradiation. 396 7

The effects of oral administration of 2 mg prazosin on several metabolic and endocrine variables were evaluated in 12 patients with hypertension (6 with normal and 6 with abnormal glucose tolerance). Prazosin was followed by a rise in plasma glucose and serum free fatty acids (FFA) in both normal and diabetic subjects; there was a trend upward in serum albumin (IRI), but growth hormone (GH), prolactin (PRL), and gastrin did not change. Although these results are in general agreement with metabolic effects of other alpha adrenergic blockers already reported, the rise in plasma glucose is at variance with studies performed with phentolamine.
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PMID:Metabolic effects of prazosin. 610

The effects of somatostatin on plasma renin activity (PRA) and blood pressure were evaluated in patients with essential hypertension (EH) and in normotensive subjects. All subjects examined were hospitalized and placed on a diet containing 7-8 g/day sodium chloride and received an intravenous infusion of somatostatin (500 microgram/20 ml of saline, for 60 min) in the basal condition. During somatostatin infusion, the mean blood pressure (MBP) remained unaffected in all patients with EH and the normotensive subjects, while the PRA decreased slightly in the EH group. When the patients with EH were classified according to their renin levels (low, normal and high), parallel significant decreases in MBP and PRA were found only in the high renin group during the somatostatin infusion. No significant change in MBP and PRA was observed in the other groups including the normotensive subjects. To assess the activity of synthetic somatostatin, the plasma levels of growth hormone (GH) and cyclic AMP were measured. These levels were lowered significantly during the infusion and the GH levels showed a rebound 15 min after cessation of the infusion. The cyclic AMP returned to the basal levels, but no rebound was observed. The above data indicate that the fall in blood pressure in the high renin group in the basal condition was probably due in part to reduced renin release by somatostatin, and the maintenance of high blood pressure especially in high renin EH.
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PMID:Effect of somatostatin on plasma renin activity and blood pressure in patients with essential hypertension. 610 26

Three studies were undertaken to reevaluate whether there is a peripheral component in the reduction of sympathetic activity caused by centrally acting drugs; and whether the antihypertensive effect of these drugs is due entirely to this reduction. Plasma growth hormone and norepinephrine concentrations were used as respective markers of central alpha-adrenoceptor stimulation and peripheral sympathetic activity. In six normal volunteers, intravenous infusion of 0.2 mg clonidine and 2 mg guanfacine was compared. The falls in systolic blood pressure and plasma norepinephrine concentration were slightly greater after clonidine (18 mm Hg and 0.22 ng/ml) than after guanfacine (12 mm Hg and 0.13 ng/ml) administration. These falls occurred earlier than the rise in growth hormone, which rose to a maximum of 23 and 20 IU/ml respectively at 45 minutes after dosing. In six patients with essential hypertension clonidine and alpha-methyldopa caused similar falls in blood pressure and plasma norepinephrine concentration although these changes occurred later with alpha-methyldopa. Plasma growth hormone levels remained undetectable in most patients. In Wistar rats the effect of central and peripheral alpha 2-blockade on clonidine-induced changes was compared. Two groups of six rats received intravenous RX 781094, 0.3 mg/kg, or vehicle 10 minutes before receiving clonidine, 5 micrograms/kg i.v. In the latter, control group, clonidine reduced mean blood pressure by 30.7 +/- 1.9 mm Hg and heart rate by 46 +/- 6.7 beats/min. Plasma norepinephrine fell from 0.22 +/- 0.023 ng/ml to 0.116 +/- 0.013 ng/ml. After pretreatment with RX 781094, blood pressure did not change and heart rate fell by 18 +/- 2.7 beats/min.(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertension
PMID:Effect of centrally acting alpha-adrenergic agonists on sympathetic nervous system function in humans. 615

Clinical examinations including echocardiography were performed for 14 acromegalic patients (five men and nine women, whose mean age was 48.6 years). Three of these had hypertension (HT) above 160/95 mmHg, three had diabetes mellitus (DM). Their cardiac sizes and functions were correlated with the durations of disease and plasma growth hormone (GH) levels. The incidences of HT and DM were also evaluated. Three of 14 patients (22%) had increased cardiothoracic ratios (greater than 55%). Electrocardiographic abnormalities were noted in three patients including two with left ventricular hypertrophy (LVH) and one with interventricular conduction defects with abnormal Q waves. By echocardiography (Table 2), nine patients (64%) were judged to be normal. The remaining five patients (36%) had abnormal echocardiograms. These included LVH (sums of the interventricular and posterior wall thicknesses greater than or equal to 25 mm) in two (25 mm in Case 10, 30 mm in Case 11), increased left ventricular end-diastolic dimension (EDD greater than or equal to 55 mm) in one (72 mm in Case 14) and both abnormalities in two patients (Cases 12 and 13). Two patients (Case 13 and 14), whose %FS were 17% and 22%, respectively, had definite evidence of congestive heart failure. Two patients (Case 11 and 13) met the diagnostic criteria for asymmetric septal hypertrophy. One patient with echocardiographic LVH and another who had increased EDD with LVH had histories of HT (Case 11 and 12). Plasma GH levels in patients with LVH were greater than 100 ng/ml (Cases 10 and 11). The left ventricular hypertrophy and/or increased EDD observed in these patients seemed related to the duration of acromegaly but not to the presence of DM. Myocardial biopsy of the right ventricle in two patients with congestive heart failure disclosed myocardial hypertrophy, myocardial fiber disarray, interstitial fibrosis and large nuclei.
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PMID:[The heart in acromegaly: an echocardiographic study]. 624 54

These studies were undertaken to clarify the role of the central and peripheral sympathetic nervous system and the renin-aldosterone system on the onset and maintenance of high blood pressure in essential hypertension (EH), and the following examinations were performed: 1) Urinary free norepinephrine and epinephrine excretion (UNEf and UEf), urinary conjugated norepinephrine and epinephrine excretion (UNEconj and UEconj), plasma norepinephrine and epinephrine concentration (PNE and PE), plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were measured in 52 patients with EH, who were divided into two groups (borderline EH: b-EH, and sustained EH: s-EH), and fifteen normals (N). 2) Cardiac index (CI), total peripheral resistance index (TPRI), appearance time, mean transit time and stroke index (SI) were determined by the dye-dilution method in eight patients with b-EH, ten patients with s-EH and ten N. 3) Clonidine was administered orally in a single dose of 150 micrograms to seven patients with s-EH and three patients with b-EH, and PNE, PE and growth hormone (GH) were measured before and after the administration. 4) Isoproterenol was infused intravenously in a dose of 0.02 microgram/kg/min for 30 min to 18 patients with s-EH and six N, then plasma cyclic AMP (c-AMP) and PRA were determined before, during and after the infusion. 5) Methacholine was injected intramuscularly in a dose of 10 mg to seven N, and PNE, PE and PRA were measured before and after the injection. There were no significant differences of PNE, PE, UNEf and UEf among the three groups (b-EH, s-EH and N), but UNEconj in both b-EH and s-EH was higher than in N (b-EH: p less than 0.1, s-EH: p less than 0.05). PRA in s-EH was slightly lower not only in N but also in b-EH. PAC in b-EH and s-EH was slightly lower than in N. The difference of PAC between b-EH and s-EH was not found. CI and SI were higher than in N (p less than 0.05), but TPRI was normal. In s-EH, TPRI was slightly elevated as compared with b-EH (p less than 0.1). In s-EH, clonidine caused a significant lowering of both blood pressure and PNE with a simultaneously marked increment of GH; on the other hand, in b-EH blood pressure and PNE did not change significantly in spite of the distinct rise of GH. After the isoproterenol infusion, PRA and c-AMP increased, and there was a significant correlation between the initial level of PRA and the maximal increment of PRA after the infusion in both s-EH and N.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Studies on the role of the central and peripheral sympathetic nervous system and the renin-aldosterone system on the onset and maintenance of high blood pressure in essential hypertension]. 632 58

Echocardiography was performed in 14 patients with acromegaly in order to characterize cardiac involvement in this disease. The left ventricle was enlarged or hypertrophic in 10 patients (71%): the fraction of myocardial shortening, an index of left ventricular contractility, was normal in all but one; and 10 patients had a reduced mitral EF slope, suggesting that their left ventricular compliance was reduced. Cardiac disease was not suspected clinically as most patients had normal clinical, ECG and X-ray examinations of the heart. Left ventricular hypertrophy occurred in the absence of hypertension, diabetes or evidence of coronary artery disease. There was a positive correlation between left ventricular wall thickness and duration of acromegaly but not between the former and growth hormone levels after fasting, suggesting that ther must be prolonged hypersecretion of growth hormone, and not simply high levels, before cardiac hypertrophy develops.
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PMID:The heart in acromegaly: correlation of echocardiographic and clinical findings. 644 20

High blood pressure occurs in about 25 p. 100 of acromegalic patients. The mechanisms involved are unknown but an unusual incidence of Conn's syndrome has been reported in acromegaly. The development of hypertension may be favored by the chronic hydro-saline inflation dependent upon the growth hormone excess. Sodium inflation is likely to be responsible for abnormal responses to angiotensin II and its antagonists in normotensive acromegalics, which make the use of these agents inappropriate for the study of the renin-angiotensin-aldosterone system. The latter can be profitably explored by the measurement of hormonal blood levels which increase normally in response to Na deprivation and orthostatism. In cases of associated Conn syndrome, the urinary level of tetrahydro-aldosterone may be normal, aldosterone being metabolized through other pathways. This appears to be independent to growth hormone hypersecretion.
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PMID:[Strategy for hormonal study in the arterial hypertension of acromegaly]. 662 20


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