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Biomedical subjects

T Marotta

Publications and source records attributed to T Marotta.

At least 37 records · Page 2Linked to original sources
PubMed1993

Doxazosin and captopril in mildly hypercholesterolemic hypertensive patients. The Doxazosin-Captopril in Hypercholesterolemic Hypertensives Study.

The evidence linking hypertension and hypercholesterolemia is strong and has fueled research into possible adverse effects of some antihypertensive agents on serum lipid profile. This multicenter, open, parallel study compares the effects of doxazosin and captopril on blood pressure, serum lipid levels, and quality of life in 224 hypercholesterolemic hypertensive patients. Blood pressure was significantly reduced in both treatment groups (p < 0.001) and was normalized (standing diastolic pressure < or = 90 mm Hg) in 73% of the doxazosin patients and 67% of the captopril group. Serum total cholesterol level was favorably reduced by both doxazosin (from 238 to 223 mg/dl, p < 0.001) and captopril (from 245 to 233 mg/dl, p < 0.001), whereas high density lipoprotein cholesterol concentration increased only in the doxazosin group (from 33 to 36 mg/dl, p < 0.001). The calculated 10-year risk for the development of coronary heart disease was reduced significantly (p < 0.001) by 28% in the doxazosin group and by 19% in the captopril group. The quality of life evaluation showed beneficial changes in both treatment groups. As a result of proven antihypertensive efficacy and a lack of unfavorable effects on lipid parameters and health status measures, these findings support the use of both doxazosin and captopril as agents of first choice in the treatment of hypertensive patients with associated lipid abnormalities.

Adult↗
PubMed1992

Evaluation of lipid metabolism during antihypertensive treatment with nicardipine sr.

The antihypertensive and metabolic effects of oral nicardipine SR 40 mg b.i.d. have been studied in 18 (15 m, 3 f; age 52.7 y) hypertensives with mild hypercholesterolaemia, treated for 3 months after a 2 week period on placebo. An iv Fat Tolerance Test (FTT) was also performed in 8 patients following placebo, treatment with acute nicardipine 20 mg and chronic administration of nicardipine SR. There was a significant fall in BP from 160/97 on placebo to 147/87 after 3 months on nicardipine SR with no change in heart rate. Blood lipids did not change significantly. The disappearance rate of the lipid emulsion in the ivFTT showed no significant change (K2 was 1.93%/min after placebo, 1.84 after nicardipine 20 mg and 1.71 after chronic treatment). The results suggest that nicardipine is an effective antihypertensive drug and that it is devoid of untoward effects on lipid metabolism.

Adult↗
PubMed1992

Resting blood pressure and cardiovascular response to sympathetic stimulation in adolescents.

The prevalence of significant hypertension in childhood may be higher than expected. We have measured sitting blood pressure in 168 11-yr-old children attending a pre-high school in the Neapolitan area on four occasions over a 3-month period. We have also measured blood pressure and heart rate during a mental arithmetic test and during isometric exercise. Prevalence of significant hypertension (diastolic blood pressure 82-90 mmHg) was 13% at the first visit and decreased to 6.5% at the last visit; prevalence of severe hypertension (diastolic blood pressure greater than or equal to 90 mmHg) decreased from 5.4% to 1.2% from the 1st to the 4th visit. No sex-related difference was observed. A more frequently positive family history of hypertension (50% vs 30% in the fifth and first quintile of blood pressure, respectively) and higher body weight (body mass index = 21.4 vs 19.3 kg/m2) were found in children in the 5th quintile of blood pressure distribution. Blood pressure increased during mental arithmetic by 10/13% of the resting values in the first quintile and by 6/11% in the last one during mental test; during handgrip the increase was of 20/37% and 24/46%, respectively: differences between quintiles did not reach statistical significance. These data show that about 8% of a Neapolitan sample of school population have high blood pressure levels, while no difference in vascular reactivity to sympathetic stimulation was detected in children with higher blood pressure.

Age Factors↗
PubMed1991

Responses of serum insulin and blood pressure to cold and handgrip in obese patients.

A close correlation between body weight and blood pressure has been frequently observed in both clinical and epidemiological studies. The aim of this clinical trial was to evaluate whether, in obese patients, there is any relationship between blood pressure, at rest or during sympathetic stimulation, and blood glucose and serum insulin, both while fasting and during an oral glucose challenge. Twenty obese patients (age 26-65 years, body weight 97 +/- 16 kg, 11 normotensive and 9 hypertensive) entered the study. After a 4-week run-in period on an isocaloric diet with normal intake of sodium, blood pressure and heart rate were measured at rest and during sympathetic stimulation induced by cold and isometric testing. Responses of glucose and insulin to a standardized 75 g oral glucose tolerance test were also evaluated. The responses of glucose and insulin to glucose challenge were not statistically different in normotensive and hypertensive obese patients. Levels of insulin in the serum in the serum in the fasting state and during glucose load were significantly correlated with the response of blood pressure to cold and isometric exercise, but not to blood pressure at rest. The response of heart rate to cold was closely related to insulin only in the subgroup of normotensives. The present findings support the hypothesis that the sympathetic nervous system, which influences secretion of insulin and regulation of blood pressure, is involved in the pathophysiology of the association of obesity and hypertension.

Adult↗
PubMed1991

Cardiovascular response to mental stress and to handgrip in children. The role of physical activity.

Cardiovascular responses to sympathetic stimulation may be altered in the early phases of life of subjects with a family history of hypertension. The possible influence of physical activity on adrenergic modulation in children is still not well known. In this study we evaluated, in a group of 162 11-year-old children from a secondary school near Naples, blood pressure and heart rate measured 4 times at 3-week intervals at rest and during adrenergic system stimulation by mental arithmetic stress and isometric exercise. Children were divided into sedentary and physically active groups according to the levels of a Saltin modified questionnaire. Family history of hypertension was also investigated. Systolic and diastolic blood pressure at rest were slightly higher in the sedentary group at each control (107/75 +/- 11/11 vs 105/73 +/- 11/11 mmHg at the first and 100/70 +/- 14/14 vs 98/69 +/- 9/9 at the last control); heart rate in the same group was higher as well (91 +/- 11 vs 87 +/- 12 beats/min, p less than 0.02 at the first and 80 +/- 9 vs 77 +/- 11 at the last control). Systolic and diastolic blood pressure increased by 7/15% during mental stress and by 23/45% during isometric exercise in the sedentary group. The corresponding blood pressure increases in the physically active group were 6/12% and 20/40%, respectively. These responses were independent of sex, body weight and family history of hypertension. These results support the hypothesis that regular physical activity in young adolescents only mildly influences resting blood pressure and cardiovascular responses during the stimulation of the sympathetic nervous system.

Blood Pressure↗
PubMed1991

Metabolic neutrality in nitrendipine therapy.

There is evidence that hypertensive patients frequently have other metabolic disorders, such as hyperlipidemia and diabetes mellitus. It is also known that the reduction in high blood pressure alone, disregarding the other cardiovascular risk factors, is unable to reduce mortality to the level of the general population. Moreover, the occurrence of metabolic side effects with some antihypertensive drugs deserves particular attention in the treatment of hypertension. Calcium antagonists seem to be devoid of untoward metabolic effects. In particular, several studies have shown that nitrendipine does not deteriorate glucose tolerance. We have evaluated the effects of nitrendipine on insulin response to i.v. glucose load: no change was observed after 2 months of treatment in both serum insulin levels and glucose percent removal rate in comparison to pretreatment values. No unfavorable change was detectable in the studies aimed at investigating the effects of nitrendipine on lipid metabolism parameters. We observed a 22% increase of the percent removal rate of a lipid emulsion (Intralipid) after nitrendipine (3.11 +/- 1.0 vs. 3.80 +/- 1.0%/min, p less than 0.03). This finding suggests a favorable effect of nitrendipine on triglyceride catabolism, possibly mediated by an interference with lipoprotein lipase activity. The metabolic neutrality of nitrendipine, therefore, leads to considering the usefulness of this drug in an antihypertensive treatment that should not disregard the global risk profile.

Blood Glucose↗
PubMed1991

Nitrendipine and metabolic balance.

Abnormalities of glucose and lipoprotein metabolism have frequently been found in hypertensive patients in both epidemiological and clinical studies. Reduction of blood pressure favorably affects the rate of cardiovascular diseases mainly when concomitant with a decrease in glucose and lipid serum levels. For these reasons antihypertensive drugs without untoward metabolic side effects should be preferred, particularly in hypertensive patients with metabolic impairment. Nitrendipine, a dihydropiridine derivative, like other calcium-entry blockers, has been proved not to deteriorate fasting glucose (75 +/- 12 vs. 75 +/- 10 mg/dl) and serum insulin (8.5 +/- 3 vs. 10.8 +/- 5 microU/ml) levels. Glucose and insulin response to an oral carbohydrate challenge (glucose % removal rate 1.4 +/- 0.2 vs. 1.5 +/- 0.3%/min; incremental area for serum insulin 955 +/- 279 vs. 905 +/- 458 microU/ml/min), serum cholesterol (192 +/- 33 vs. 200 +/- 43 mg/dl), triglyceride (83 +/- 57 vs. 84 +/- 37 mg/dl) and high-density lipoprotein cholesterol (46 +/- 9 vs. 50 +/- 14 mg/dl) were not affected as well. It is therefore possible to conclude that nitrendipine may be safely prescribed when the antihypertensive activity of a calcium-entry blocker is required.

Blood Glucose↗
PubMed1991

Metabolic disturbances and antihypertensive therapy.

Arterial hypertension is frequently associated with metabolic abnormalities. Hyperinsulinemia and insulin resistance are found in obese patients, in non-insulin-dependent diabetics and in some hypertensive patients, irrespective of whether the patients are overweight or have diabetes mellitus. Membrane transport abnormalities, such as increased sodium-lithium exchange associated with hypertension are also significantly related to disturbances in lipid metabolism. Increased sympathetic nervous system activity is a well established feature of arterial hypertension and this may also affect glucose and lipid metabolism. The possibility of these metabolic alterations in the hypertensive patient must be taken into account when deciding upon treatment. Attention to diet is mandatory and includes advice to reduce energy, salt and saturated fat intakes and to increase the intake of less digestible fiber and of potassium; alcohol consumption should be limited. Energy expenditure by regular aerobic physical exercise should be encouraged and continuous effort is necessary to help patients stop smoking. In patients with high blood pressure and abnormalities in lipid and glucose metabolism, it is wise to start pharmacological treatment with drugs that are known to be neutral in their metabolic effects, such as calcium antagonists, angiotensin converting enzyme inhibitors or alpha-blocking agents.

Antihypertensive Agents↗
PubMed1990

Brain damage from 125I brachytherapy evaluated by MR imaging, a blood-brain barrier tracer, and light and electron microscopy in a rat model.

Changes in normal rat brain were studied acutely, and at 3, 6, 9, and 12 months following interstitial brachytherapy with high-activity 125I seeds. An 80-Gy radiation dose was administered to an area with a 5.5-mm radius. Effects were measured with magnetic resonance (MR) imaging (with and without gadolinium enhancement), leakage of horseradish peroxidase (HRP), electron microscopy, and light microscopy. Significant histological damage was seen at radiation doses above 295 Gy, and breakdown of the blood-brain barrier was observed only in tissue receiving a dose of 165 Gy or greater. Blood-brain barrier breakdown increased up to the 6-month time point, and thereafter appeared to stabilize or decrease. The area of blood-brain barrier disruption indicated by gadolinium-enhanced MR imaging was greater than that indicated by leakage of HRP.

Animals↗
PubMed1989

Adrenergic blocking agents and lipoprotein lipase activity.

Lipoprotein lipase activity, total serum cholesterol and triglycerides, HDL cholesterol were determined before and after two weeks of treatment with a low dose of an alpha 1-blocking agent (prazosin) or of a beta-adrenergic-blocking drug (metoprolol). Lipoprotein lipase activity was almost doubled after prazosin (p less than 0.02) and practically unchanged after metoprolol, at a time and at a drug dosage when only minor changes in blood pressure and serum lipids were detectable. HDL cholesterol was slightly but significantly increased after prazosin (p less than 0.05). Heart rate was increased after prazosin (p less than 0.05) and decreased after metoprolol (p less than 0.01).

Adult↗
PubMed1989

Enhancement of exogenous triglyceride removal following calcium channel blockade.

Adrenergic regulation of lipid metabolism is mediated by various intracellular messengers, including calcium ions. Little is known about the role of calcium in the catabolism of triglyceride-rich lipoproteins. Aim of this study was to investigate whether blockade of calcium influx across the cell membrane influences lipid metabolism in man. The calcium entry blocker nitrendipine was administered to 10 hypertensive, normolipidemic subjects for eight weeks at the dose of 10 mg b.i.d. An enhancement in plasma clearance of triglyceride was observed after nitrendipine administration: fractional removal rate of the triglyceride emulsion Intralipid increased by 22% (from 3.13 +/- 1.1 after placebo to 3.81 +/- 1.4% min after nitrendipine, p less than 0.03). Fasting serum triglyceride was not shifted (83 +/- 57 vs 84 +/- 37 mg/dl). Total serum cholesterol and cholesterol in high density lipoproteins were also unchanged during the study. No evidence of change in insulin response was detected. It is hypothesized that calcium plays a role in the modulation of lipoprotein lipase, the enzyme mainly responsible of the removal of exogenous triglyceride from plasma. Alternatively, the increase in the clearance rate of the triglyceride emulsion might be explained by the vasodilating activity of nitrendipine.

Adult↗
PubMed1988

Addition of chlorthalidone to slow-release nifedipine in the treatment of arterial hypertension: a controlled study versus placebo.

The use of calcium antagonists and diuretics in combination for treatment of hypertension is controversial. In a single-blind study 16 patients (8 men, 8 women, age range 39 to 62 years) with primary hypertension of mild to moderate degree were given slow-release nifedipine 20 mg twice daily for 6 weeks, thereafter either chlorthalidone 25 mg (Group A) or placebo (group B) daily was randomly added for a further 6-week period. Blood pressure (BP), heart rate, plasma renin activity (PRA), aldosterone, and 24 hour urinary electrolytes were evaluated. Nifedipine decreased supine BP from 159/92 +/- 16/8 to 151/89 +/- 10/6 mmHg in group A and from 162/94 +/- 20/12 to 145/85 +/- 14/6 mmHg in group B. A further fall to 139/84 +/- 7/6 mmHg (p less than .05) was observed after addition of chlorthalidone. PRA significantly increased with combined treatment compared to baseline (3.3 +/- 0.8 to 9.9 +/- 3.3 ng/ml/hr; p less than 0.05). A slight reduction of 24-hour urinary calcium was observed after the addition of chlorthalidone. These data indicate that the combination of nifedipine and chlorthalidone might be beneficial in the treatment of arterial hypertension.

Adult↗
PubMed1988

Acute and chronic effects of dihydropyridines on triglycerides in humans.

Several drugs used in the treatment of hypertension have been shown to affect lipid metabolism. A few studies have examined in detail the effects of calcium antagonists on blood lipids. We investigated the effects of nifedipine and nitrendipine on blood lipids using two experimental protocols. The first study was a double-blind, randomized, placebo-controlled trial to assess the effects of acute oral administration of nifedipine 10 mg on blood lipids in 10 patients (9 males, 1 female; age range 26-50 years) with mild hypertriglyceridemia. Serum triglycerides were not significantly affected (from 310 +/- 120 to 280 +/- 110 mg/dl 2 h after nifedipine) but a slight decrease was observed in patients with higher baseline levels. In the second study, an intravenous fat tolerance test (ivFTT, Intralipid 10%, 1 ml/kg body weight, as a bolus) was performed before and after chronic oral administration of nitrendipine 10 mg b.i.d. in 10 mild to moderate hypertensive patients (7 males, 3 females; age range 40-60 years). After nitrendipine treatment, the fractional removal rate (K2) of the lipid emulsion was significantly increased from 3.1 +/- 0.9 to 3.8 +/- 0.9% min (p less than 0.05). The main findings of these studies suggest that the secretion of lipoprotein lipase might be stimulated by calcium antagonists. Alternatively, the vasodilation produced by these compounds may influence triglyceride removal by expanding the capillary bed where the enzyme exerts its activity. In conclusion, calcium antagonists do not seem to cause unwanted side effects on blood lipids and apparently enhance triglyceride removal.

Adult↗
PubMed1988

Is the sympathetic nervous system altered in children with familial history of arterial hypertension?

The sympathetic nervous system has been investigated in 42 children with family history of arterial hypertension and 68 children of the same age without hypertensive relatives. Pressure responses to mental arithmetic and to isometric handgrip stress were measured in both groups, along with 24 h catecholamine excretion. Resting blood pressure and heart rate did not show any difference between groups. The increase in diastolic pressure during the mental arithmetic exercise was, however, significantly greater in children with family history of hypertension. A sharp increase in blood pressure and heart rate was observed during isometric handgrip in both groups without any significant difference. Twenty-four hour catecholamine urinary excretion was significantly higher in the group with family history of hypertension (31 +/- 15 vs. 23 +/- 13 micrograms/24 h; p less than 0.05). These results seem to indicate that an initial impairment of the sympathetic activity is already detectable in young offspring of hypertensive patients.

Blood Pressure↗
PubMed1987

Calcium antagonists and thiazide diuretics in the treatment of hypertension.

The usefulness of the combination of nifedipine and chlorthalidone has been investigated in mild to moderate hypertensive patients (seven men, seven women; age range 39-62 years) by adding the diuretic to nifedipine monotherapy. After a 2 week washout, slow-release nifedipine 20 mg b.i.d. was given for 6 weeks, followed by addition of either chlorthalidone 25 mg (group A) or placebo (group B) q.d. for a further 6-week period. Blood pressure, heart rate, plasma renin activity, and 24-h urinary Na and K excretion were measured at baseline and at the end of each treatment period. Nifedipine decreased blood pressure in the two groups. A further significant fall was observed after chlorthalidone was added. No further change was detected after placebo in group B. Plasma renin activity after 1 h standardized walk significantly increased after combined treatment compared with baseline (3.3 +/- 1.2 to 9.4 +/- 5.3 ng/ml/h; p less than .05). No change was observed in 24 h urinary Na and K in the two groups. Venous distensibility measured by strain gauge plethysmography was slightly reduced during nifedipine monotherapy. Our data therefore suggest that chlorthalidone potentiates the antihypertensive effect of nifedipine despite an increase of renin activity.

Adult↗
PubMed1986

Effects of alpha-adrenergic and beta-adrenergic receptor blockade on lipid metabolism.

The role of lipoprotein lipase in the pathophysiology of lipid changes during alpha-receptor or beta-receptor blockade was evaluated in this clinical trial. Thirty hypertensive patients were given 2 mg of prazosin twice daily or 100 mg of metoprolol twice daily for 10 weeks, according to an open, randomized protocol. Both drugs were effective in reducing arterial blood pressure (from 153 +/- 16/102 +/- 6 mm Hg to 146 +/- 12/92 +/- 8 mm Hg with prazosin and from 158 +/- 17/103 +/- 8 to 144 +/- 14/94 +/- 10 mm Hg with metoprolol). Prazosin significantly reduced total plasma cholesterol from 202 +/- 39 to 188 +/- 36 mg/dl and increased high-density lipoprotein cholesterol from 36 +/- 8 to 40.5 +/- 11 mg/dl. Prazosin did not affect plasma triglycerides levels, whereas patients taking metoprolol had a slight rise in these levels, from 122 +/- 42 to 142 +/- 57 mg/dl, along with a decrease in high-density lipoprotein cholesterol from 37 +/- 10 to 31 +/- 8 mg/dl. The concentration of apoprotein B did not change significantly with either treatment. Lipoprotein lipase activity increased in the prazosin group from 28.4 +/- 16 to 37.7 +/- 14 mumol/liter per minute (p less than 0.01), but did not change significantly (29.9 +/- 12 versus 32.8 +/- 8 mumol/liter per minute) in patients treated with the beta blocker. These data, which confirm previous reports of serum lipid changes during antihypertensive therapy, suggest that alpha1 blockers may interfere with lipoprotein lipase, possibly by reducing its catecholamine-mediated inactivation.

Adolescent↗