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Biomedical subjects

V Papademetriou

Publications and source records attributed to V Papademetriou.

At least 55 records · Page 3Linked to original sources
PubMed1995

Miles run per week and high-density lipoprotein cholesterol levels in healthy, middle-aged men. A dose-response relationship.

OBJECTIVE: To examine the association between miles run per week and high-density lipoprotein cholesterol levels in healthy middle-aged men. BACKGROUND: Regular exercise increases levels of high-density lipoprotein cholesterol. However, the exercise requirements for such increases are not well defined. METHODS: Healthy, nonsmoking men (n = 2906; age, 43 +/- 4 years) completed a questionnaire on health habits and physical activities and a symptom-limited exercise test. They were then stratified on the basis of the number of miles run per week. Six groups, with mileages of 0, 5, 9, 12, 17, and 31 per week, were established. RESULTS: A gradual increase in high-density lipoprotein cholesterol level was observed with increased miles (0.008-mmol/L [0.308-mg/dL] increase in high-density lipoprotein cholesterol level per mile). Most of the changes were associated with distances of 7 to 14 miles per week. Levels of low-density lipoprotein cholesterol, triglycerides, and the ratio of total cholesterol to high-density lipoprotein cholesterol also improved with weekly mileage. The high-density lipoprotein cholesterol level correlated significantly with all exercise components, anthropometric measures, and alcohol consumption. Group comparisons disclosed significant differences (P < .05) in exercise time to exhaustion, miles run per week, body fat, body weight, and body mass index. Age and alcohol consumption were similar across groups. CONCLUSIONS: These results indicate a dose-response relationship between miles run per week, high-density lipoprotein cholesterol level, and other lipoprotein-lipid levels. Most changes were noted in those who ran 7 to 14 miles per week at mild to moderate intensities. A mile-age threshold for changes in high-density lipoprotein cholesterol level was not observed. However, when compared with those of the nonexercising group, high-density lipoprotein cholesterol levels attained statistical significance at 7 or more miles per week.

Cholesterol, HDL↗
PubMed1995

Low-dose drug combination therapy: an alternative first-line approach to hypertension treatment.

To investigate the concept that the initial treatment of hypertension with low doses of two antihypertensives that have different modes of action and additive effects may achieve control of blood pressure and minimize the dose-dependent adverse effects seen with conventional monotherapy, a randomized, double-blind parallel group dose-escalation study was conducted. After a 4 to 5 week placebo washout period, 218 men and women with diastolic blood pressure between 95 and 114 mm Hg were randomly allocated to take: amlodipine (2.5 to 10 mg), enalapril (5 to 20 mg), and the low-dose combination of bisoprolol (2.5 to 10 mg) with 6.25 mg of hydrochlorothiazide (HCTZ). All drugs were administered once daily, titrated to optimal response, and taken for a total of 12 weeks. Blood pressure was measured 24 hours after dose. The response rates (either a diastolic blood pressure < or = 90 mm Hg or a decrease of diastolic pressure > or = 10 mm Hg) were 71% for bisoprolol-6.25 mg HCTZ, 69% for amlodipine, and 45% for enalapril. The mean decreases in systolic/diastolic blood pressure from baseline were 13.4/10.7, 12.8/10.2, and 7.3/6.6 mm Hg for bisoprolol-6.25 mg HCTZ, amlodipine, and enalapril, respectively. The mean change with enalapril was less than the other drugs (p < 0.01), although the once-daily dosing of enalapril and the maximum dose of 20 mg might not have been optimal for this agent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Cardiorespiratory fitness and coronary heart disease risk factor association in women.

OBJECTIVES: The purpose of this study was to examine the association between cardiorespiratory fitness and coronary risk factors in healthy, nonsmoking adult women. BACKGROUND: A sedentary life-style is recognized as an independent risk factor for coronary heart disease, and increasing physical activity is strongly recommended to reduce this risk. However, studies examining the effects of increased physical activity on coronary heart disease risk factors in women are relatively few, and the findings have been equivocal. METHODS: Subjects provided written informed consent, completed a questionnaire on medical history and performed an exercise tolerance test. Blood chemistry and lipid levels were determined from fasting blood samples. Three fitness categories were established on the basis of treadmill time to exhaustion and were adjusted for age. RESULTS: The women in the lowest fitness category had less favorable lipid profiles, blood glucose levels, blood pressures and anthropometric indexes than those in the moderate and high fitness categories. CONCLUSIONS: Moderate fitness (equivalent to 10 metabolic equivalents [METs]) is required to improve the coronary risk profile in women.

Adult↗
PubMed1994

Effects of diltiazem, metoprolol, enalapril and hydrochlorothiazide on frequency of ventricular premature complexes.

Ventricular arrhythmias occur frequently in patients with hypertensive left ventricular (LV) hypertrophy and have been associated with increased incidence of sudden death. In this study, the effect of various antihypertensive medications on ventricular arrhythmias was evaluated in 31 hypertensive patients with moderate to severe LV hypertrophy. Patients were assessed at baseline (after 3 weeks of placebo treatment) and after treatment with each of 4 monotherapies: diltiazem 120 or 240 mg/day, metoprolol 100 or 200 mg/day, enalapril 10 or 20 mg/day and hydrochlorothiazide 50 or 100 mg/day. Each drug therapy was administered for 4 weeks. The sequence of each treatment was determined at random. Echocardiographic measurements and electrocardiograms were obtained only at baseline. Biochemical measurements and 48-hour Holter monitoring were obtained at baseline and at the end of each treatment. All treatments resulted in a significant but similar decrease in blood pressure. In the group as a whole diltiazem decreased ventricular premature complexes (VPCs) by 65% (p < 0.05) and metoprolol by 52% (p = 0.07). Enalapril and hydrochlorothiazide had no effect. In 12 patients with > or = 5 VPCs/hour at baseline, diltiazem and metoprolol decreased VPCs by 66% (p < 0.05). It is concluded that in hypertensive patients with moderate to severe LV hypertrophy, both diltiazem and metoprolol significantly reduce VPCs.

Analysis of Variance↗
PubMed1994

Effect of diuretics on cardiac arrhythmias and left ventricular hypertrophy in hypertension.

Ventricular arrhythmias pose a serious risk in patients with high blood pressure. The concept that diuretics predispose to life-threatening arrhythmias, however, was originally based solely on observations made in patients with severe congestive heart failure pretreated with digitalis and not in patients with high blood pressure. In hypertensive patients, some studies have also indicated that diuretic therapy may be associated with an increase in premature ventricular beats, though most have failed to demonstrate a conclusive link between hypokalemia and the precipitation of such cardiac arrhythmias. Prospective studies, however, have demonstrated that diuretic therapy had no effect on the incidence of serious ventricular arrhythmias in hypertensive patients whether they had left ventricular hypertrophy (LVH) or not, and neither at rest nor during or immediately following dynamic exercise. Correction of diuretic-induced hypokalemia similarly had no effect on the incidence of ventricular arrhythmias. In hypertensive patients, LVH is an independent and particularly sinister risk factor for cardiovascular morbidity and mortality, and its regression is now a specific goal of antihypertensive therapy. Diuretics have been shown to be at least as effective in that respect as other antihypertensive agents. The Veterans Administration Cooperative Study Group reported that after 2 years of treatment, only hydrochlorothiazide of 6 antihypertensive regimens resulted in significant reduction of left ventricular mass. In the Treatment of Mild Hypertension Study, all the antihypertensive drugs used resulted in reductions in LVH but the diuretic caused a significantly greater reduction than other non-diuretic agents. In the Systolic Hypertension in the Elderly Study, which primarily used diuretics, there was a significant reduction in LVH at 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1993

Application of ambulatory blood pressure monitoring in differentiating between antihypertensive agents.

PURPOSE: This multicenter, double-blind, parallel group study assessed the usefulness of the ambulatory blood pressure monitoring (ABPM) technique in differentiating between the once-daily administration of the beta blockers bisoprolol (10 to 20 mg) and atenolol (50 to 100 mg) in terms of efficacy and duration of action. PATIENTS AND METHODS: The study population consisted of 659 patients with essential hypertension and an average office diastolic blood pressure (BP) between 95 and 115 mm Hg after 4 weeks of placebo treatment. Office BPs were recorded at the end of the 24-hour dosing interval (trough). ABPM was performed in 11 of the 28 institutions participating in this study in a total of 203 patients. These procedures were performed at the end of the placebo phase and again after 8 weeks of active treatment. RESULTS: With the use of conventionally measured office BPs, the two drugs significantly (p < 0.001) decreased trough systolic and diastolic BPs to a similar extent. By 24-hour monitoring, bisoprolol demonstrated a 33% greater reduction in whole-day average diastolic BP than did atenolol (11.6 +/- 0.7 mm Hg versus 8.7 +/- 0.8 mm Hg, p < 0.01). Significant treatment differences in systolic (p < 0.05) and diastolic (p < 0.01) BPs were also noted for bisoprolol compared with atenolol during the final 4 hours of the dosing interval (-13.2 +/- 1.5/-10.9 +/- 1.0 mm Hg versus -8.9 +/- 1.6/-7.3 +/- 1.1 mm Hg, respectively), and over the time period 6:00 AM to noon (-14.2 +/- 1.3/-11.5 +/- 0.9 mm Hg versus -9.9 +/- 1.4/-7.7 +/- 0.9 mm Hg). CONCLUSIONS: Whereas conventional BP measurements did not detect differences in the antihypertensive effects of the beta blockers bisoprolol and atenolol, ABPM revealed significant treatment differences in both the efficacy and duration of action of these two agents. These findings indicate the power of this technique to discriminate potentially important differences between apparently similar antihypertensive drugs.

Adult↗
PubMed1992

Diuretics in hypertension: clinical experiences.

Diuretics have long been used in the treatment of hypertension and are outstandingly efficacious when used either alone or in combination with other antihypertensive compounds. Blood pressure is controlled with diuretics alone in over 50% of patients and in over 80% in combination with other drugs. Thiazide diuretics were used singly and in combination in the early VA Co-operative studies that demonstrated decrease in cardiovascular morbidity with blood pressure control. Subsequent studies have confirmed these early findings and clearly demonstrated that the thiazide diuretics are as effective in lowering blood pressure as other currently available antihypertensive compounds. Diuretics, like all other antihypertensives, have side effects, of which the most important ones are hypokalaemia, alterations of the plasma lipid profile, hyperuricaemia and glucose intolerance. Diuretic-induced hypokalaemia may be hazardous in the presence of digitalis, but does not appear to have any inherent propensity to induce life-threatening arrhythmias. Diuretics remain amongst first-line drugs in the treatment of high blood pressure due to their efficacy, especially in blacks and the elderly, the potentiation of the antihypertensive efficacy of other compounds, their low side effect profile and their low cost.

Arrhythmias, Cardiac↗
PubMed1991

Therapeutic adherence in the elderly: transdermal clonidine compared to oral verapamil for hypertension.

This double-blind, double-dummy, randomized clinical trial, conducted in elderly patients with mild hypertension, compared adherence to treatment, efficacy, side effects, and quality of life during treatment with transdermal clonidine versus oral sustained-release verapamil (verapamil-SR). Blood pressure declined significantly--from 148/95 mm Hg at baseline to 139/84 after titration and 135/86 after maintenance--with transdermal clonidine (n = 29), and from 156/96 to 144/85 and 148/88, respectively, with verapamil-SR (n = 29). Adverse event rates and quality-of-life questionnaire responses were similar in the two treatment groups. Transdermal clonidine was worn as directed during more than 96% of patient-weeks of treatment. Compliance with the oral verapamil regimen was less consistent: Verapamil-SR was taken as directed during approximately 50% of patient-weeks of therapy, and individual compliance, assessed by tablet counts, varied from 50-120%. In all, 86% of subjects were satisfied or highly satisfied with the convenience of transdermal therapy; 87% reported that side effects were slightly or not bothersome; 65% indicated that transdermal patches were more convenient than oral therapy; and almost 60% preferred transdermal to oral therapy. In this study transdermal clonidine and oral verapamil were equally safe and effective. A substantial majority of patients preferred transdermal to oral therapy, and adherence to treatment was greater with transdermal therapy.

Administration, Cutaneous↗
PubMed1989

Effects of diuretic therapy and exercise-related arrhythmias in systemic hypertension.

The effect of aerobic exercise on cardiac arrhythmias, plasma catecholamines, potassium and magnesium in patients with systemic hypertension was assessed. Twenty patients (age 54 +/- 8 years) with uncomplicated hypertension underwent exercise treadmill testing twice while receiving placebo and twice while receiving hydrochlorothiazide 100 mg daily. Blood samples for electrolytes and catecholamines were obtained at rest, at peak exercise and 10 minutes after exercise. There were no substantial differences comparing the first to the second placebo phase or the first to the second treatment period. As expected, hydrochlorothiazide treatment caused a significant decrease in serum potassium (4.00 +/- 0.44 to 3.32 +/- 0.49 mEq/liter, p less than 0.001). Serum magnesium did not change with treatment. Serum potassium, serum magnesium and plasma catecholamines increased significantly with exercise. No rebound hypokalemia occurred during recovery. Occasional ventricular premature contractions were noted at rest during all phases of the study, with only a slight increase in frequency during exercise. Couplets were noted only rarely. No difference in the frequency or complexity of arrhythmias was noted between placebo and treatment periods. Diuretic therapy or diuretic-induced hypokalemia has no profound effect on cardiac arrhythmias during or after exercise in patients with uncomplicated systemic hypertension.

Blood Pressure↗
PubMed1989

Exercise blood pressure response and left ventricular hypertrophy.

Although hypertension is the major cause of left ventricular hypertrophy (LVH), numerous studies failed to demonstrate a close correlation between resting blood pressure (BP) and degree of LVH. Some authors have shown better correlation between BP at work and left ventricular mass (LV mass), whereas other studies supported an association between catecholamines or angiotensin II and LV mass. In this study we investigated the relationship of resting and exercise BP and catecholamines to the degree of LVH. Nineteen patients with established mild to moderate hypertension were studied. Blood pressure was measured following a ten-minute rest and every three minutes during exercise using a Bruce protocol. Electrolytes, epinephrine (EP), and norepinephrine (NE) were measured at rest, at peak exercise, and at ten-minutes postexercise. Resting BP averaged 154 +/- 24/99 +/- 9 mm Hg and at three minutes of exercise 195 +/- 30/101 +/- 6 (P less than .001). Resting EP was 51 +/- 20 pg/mL, NE 314 +/- 187, and at peak exercise EP was 107 +/- 61 (P less than .001) and NE 1016 +/- 566 (P less than .001). The average LV mass was 277 +/- 85 g. A significant correlation was found only between systolic BP at three minutes of exercise and LV mass (r = .479, P less than .04). No other variable correlated significantly with LV mass. These data suggest that systolic BP achieved at low level of exercise (5 mets), corresponding to usual daily activities, may be the most important determinant of LVH in patients with hypertension.

Blood Pressure↗
PubMed1989

Diuretic therapy and exercise in patients with systemic hypertension.

Twenty patients with uncomplicated systemic hypertension underwent treadmill testing twice during placebo treatment and twice during hydrochlorothiazide treatment. Data were collected at rest, at peak exercise and 10 min after exercise. Serum potassium, magnesium and plasma catecholamines increased significantly with exercise. There was no rebound hypokalaemia during the recovery period. Occasional ventricular premature complexes were recorded in all phases of the study. However, there was no difference in the frequency or complexity of arrhythmias between the placebo and the treatment periods.

Arrhythmias, Cardiac↗
PubMed1988

Thiazide therapy is not a cause of arrhythmia in patients with systemic hypertension.

Forty-four patients with uncomplicated systemic hypertension underwent 48-hour electrocardiographic monitoring before and after four weeks of treatment with hydrochlorothiazide, 100 mg daily. Plasma potassium concentration decreased from 4.07 +/- 0.26 mmol/L (4.07 +/- 0.26 mEq/L) to 3.36 +/- 0.44 mmol/L (3.36 +/- 0.44 mEq/L). The average number of premature ventricular contractions, couplets, or ventricular tachycardia episodes did not change significantly. Twenty patients had more than minimal ventricular ectopy (class 2 to 5) before and 17 after diuretic therapy. Further analysis revealed that following diuretic therapy, neither patients with plasma potassium levels of 3.4 mmol/L or less (less than or equal to 3.4 mEq/L) nor patients with left ventricular hypertrophy had increased ectopy as compared with baseline. At baseline, patients with left ventricular hypertrophy had more arrhythmias than patients without. We conclude that the results of this study provide no evidence that diuretic therapy or diuretic-induced hypokalemia results in increased ventricular ectopy, and that patients with left ventricular hypertrophy may have more ventricular ectopy than patients without, but these arrhythmias are not adversely effected by diuretic therapy.

Cardiac Complexes, Premature↗
PubMed1988

Incidence and cardiac effects of systemic venous air embolism. Echocardiographic evidence of arterial embolization via noncardiac shunt.

Central nervous system dysfunction in venous air embolism may result from air entering the arterial circulation. Using two-dimensional and pulsed-wave Doppler echocardiography, this study not only documented the frequent presence of air in the right heart chambers of patients undergoing upright neurosurgery or pacemaker insertion, but also documented the presence of air in the left atrium and left ventricle of one patient via noncardiac shunt. Studies in dogs confirmed paradoxical air embolism in the absence of anatomic communications between right and left heart chambers. Systemic venous air also produced a dose-dependent increase in pulmonary artery pressure and diastolic flattening of the ventricular septum with increase in left ventricular filling pressure despite preserved systolic function.

Aged↗
PubMed1985

Echocardiographic assessment by computer-assisted analysis of diastolic left ventricular function and hypertrophy in borderline or mild systemic hypertension.

Systemic hypertension is a common cause of congestive heart failure. However, left ventricular (LV) systolic function remains normal for many years in patients with mild or moderate hypertension. In this study, high-quality M-mode echocardiograms were recorded in 7 patients with borderline hypertension, 14 patients with mild hypertension and 15 normal persons. Measures of systolic and diastolic LV function and the degree of LV hypertrophy were studied with the assistance of a tablet digitizer and dedicated microcomputer. Average blood pressure was 125 +/- 10/77 +/- 7 mm Hg in normal subjects, 146 +/- 18/92 +/- 2 mm Hg in patients with borderline hypertension and 150 +/- 11/102 +/- 4 in patients with mild hypertension. Indexes of systolic LV function were similar in all 3 groups. The peak rate of early relaxation of the LV posterior wall was significantly decreased in the group of patients with mild hypertension (4.7 vs 6.6 sec-1, p less than 0.01). The mitral valve closure rate was 150 +/- 32 mm/s in normal subjects, 119 +/- 35 mm/s in patients with borderline hypertension and 106 +/- 26 mm/s (p less than 0.001) in patients with mild hypertension. Mild LV hypertrophy was present in 6 of 7 patients with borderline and 13 of 14 patients with mild hypertension. The degree of hypertrophy and the level of blood pressure correlated poorly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗