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Showing papers by "Robert Fagard published in 1987"


Journal ArticleDOI
TL;DR: It is concluded that the left ventricular hypertrophy observed in cyclists is not associated with changes in ventricular stiffness, as estimated fromleft ventricular inflow Doppler velocimetry.

76 citations


Journal ArticleDOI
TL;DR: It is concluded that calcium intake is low in blacks but stimulation of parathyroid hormone and 1,25(OH)2D3 required to achieve normocalcemia does not occur.
Abstract: The serum and urinary calcium, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and parathyroid hormone (PTH) were studied in healthy black and white males living in Belgium, and the results were compared to data in blacks of similar age living in Zaire. Dietary calcium and vitamin D were estimated in a subsample of blacks and whites examined in Belgium. Compared to whites (9.51±0.28 mg%) serum calcium was somewhat lower in blacks (9.26±0.27 mg% in Belgium; 9.19±0.48 mg% in Zaire). The 24 hour urinary calcium excretion averaged 215.0±16.7 mg% in whites and was higher (P<0.05 or less) than in blacks (115±71 mg% in Belgium; 36±33 mg% in Zaire). The serum 25OHD levels were similar in whites and blacks evaluated in Zaire, both being higher (P<0.05 or less) than in blacks living in Belgium. In the latter blacks, an inverse correlation was observed between the 25OHD level and the duration of the stay in a temperate climate. Parathyroid hormone levels were slightly higher in blacks living in Belgium than in the other two groups of subjects. The serum levels of 1,25(OH)2D3 and human vitamin D-binding protein were similar in the three groups of subjects. Dietary calcium averaged 541±152 mg/day in blacks and was significantly (P<0.001) less than in whites (1,203±508 mg/day), whereas no significant difference was observed in dietary vitamin D intake between blacks and whites. It is concluded that calcium intake is low in blacks but stimulation of parathyroid hormone and 1,25(OH)2D3 required to achieve normocalcemia does not occur.

72 citations


Journal ArticleDOI
TL;DR: At rest as well as during exercise, Aldo rose with increasing ANG II, but the stimulatory effect of ANG II on Aldo was attenuated with higher sodium intake, as estimated from UVNa, independent of the level of physical activity.
Abstract: The exercise-related increase in plasma renin activity (PRA) and in the plasma concentration of angiotensin II (ANG II) and aldosterone (Aldo) was studied in 43 healthy volunteers whose 24-h urinary sodium excretion (UVNa) ranged from 10 to 250 mmol. Arterial blood samples were obtained at rest and during bicycle ergometry. Compared with rest, PRA, ANG II, and Aldo rose to a similar extent during light and moderate exercise. However, at peak exercise ANG II increased significantly more (P less than 0.001) than PRA and Aldo. Thus, with increasing intensity of exercise, the slope of the linear regression of ANG II on PRA became significantly (P less than 0.001) steeper, whereas at maximal exercise the Aldo response did not follow the acute rise in ANG II. At rest as well as during exercise, Aldo rose with increasing ANG II, but the stimulatory effect of ANG II on Aldo was attenuated with higher sodium intake, as estimated from UVNa. Finally, independent of the level of physical activity, UVNa was negatively correlated with PRA, ANG II, and Aldo.

47 citations


Journal ArticleDOI
TL;DR: The data indicate that cardiac factors are not significantly involved in the inheritance of aerobic power and suggest that cardiac hypertrophy in athletes is secondary to training.
Abstract: The contribution of heredity to the interindividual variability of maximum oxygen uptake and of cardiac size and function of healthy male twins, age 18 to 31 years, was studied to evaluate the role of the heart in the inheritance of aerobic power. Twelve pairs of monozygotic and 12 pairs of dizygotic twins were examined. Weight (p

43 citations


Journal ArticleDOI
TL;DR: It is suggested that higher blood pressure in the rural setting was mostly accounted for by the older age of the population, and correlated positively with age, weight, pulse rate, sex and sodium:potassium ratio.
Abstract: Blood pressure and anthropometric characteristics were studied in 312 rural and 675 urban Bantu of Zaire aged 10 years and more; proteinuria and the urinary sodium to potassium ratio were determined. On average, systolic and diastolic pressure were higher in rural than in urban Bantu, and rose with advancing age in both populations. However, rural Bantu were older, lighter and smaller, and had a lower sodium:potassium ratio than urban Bantu. Using multiple regression analysis, systolic and diastolic pressures correlated positively with age, weight, pulse rate, sex and sodium:potassium ratio; diastolic pressure also correlated negatively to height. After adjusting blood pressure for these independent correlates, systolic pressure remained significantly higher in rural Bantu. However, no significant difference persisted between the two populations after adjusting blood pressure for age alone. The prevalence of hypertension in rural and urban Bantu increased with age and was 14.2 and 9.9%, respectively, for participants at least 20 years old; women were more affected in the rural area, whereas men were more affected in the urban population. The occurrence of proteinuria was higher in rural Bantu than in urban; it was similar in participants with and without definite hypertension. It is suggested that higher blood pressure in the rural setting was mostly accounted for by the older age of the population.

42 citations


Journal ArticleDOI
TL;DR: The plasma cGMP and cAMP concentrations had returned to the prerace levels 12 h after the marathon, whereas the plasma alpha-ANP concentration was significantly lower than the base-line values and increased above the pre race values 36 h and 7 days later.
Abstract: Plasma alpha-atrial natriuretic peptide (alpha-ANP) concentration and levels of cyclic nucleotides [guanosine 3′,5′-cyclic monophosphate (cGMP) and adenosine 3′,5′-cyclic monophosphate (cAMP)] were studied in 23 runners before and after a marathon race. Blood samples were drawn from an antecubital vein the morning before the race (base line), at 3 P.M. (i.e., 2 h before the start), on arrival, and 12 and 36 h and 7 days later. Compared with the base-line values of plasma alpha-ANP (5 pmol/l), cGMP (3.8 nmol/l), and cAMP (15.8 nmol/l), the plasma levels of alpha-ANP, cGMP, and cAMP were increased immediately after the marathon, respectively, to 12.0 pmol/l, 12.7 nmol/l, and 50.5 nmol/l. The increase in the plasma alpha-ANP concentration was related (r = 0.85; P less than 0.001) to the changes in plasma cGMP, plasma lactate, hematocrit, and body weight. The plasma cGMP and cAMP concentrations had returned to the prerace levels 12 h after the marathon, whereas the plasma alpha-ANP concentration was significantly lower (3.1 pmol/l) than the base-line values and increased above the prerace values 36 h (7.5 pmol/l) and 7 days (6.8 pmol/l) after the marathon. The plasma cGMP level was also higher 36 h (5.4 nmol/l) and 7 days (5.0 nmol/l) after the marathon race.

24 citations


Journal ArticleDOI
TL;DR: The effect of supine bicycle exercise on the carotid baroreceptor reflex was investigated in 10 normal volunteers who were studied at rest and during moderate and severe exercise, i.e., at 33% and 66% of their previously determined maximal exercise capacity.

21 citations


Journal ArticleDOI
TL;DR: Monotherapy with nitrendipine or acebutolol offers an effective, safe first‐line antihypertensive treatment in blacks entered in this study; with the described dosages and therapeutic schedule, nitrendIPine was somewhat more effective than ace butolol.
Abstract: The long-term efficacy of nitrendipine and acebutolol was assessed during a 40-week double-blind randomized trial in 60 hypertensive blacks. Nitrendipine (mean dose 32 mg/day) and acebutolol (414 mg/day) were administered in monotherapy in increasing dosage and mefruside was added in patients not controlled by monotherapy. The recumbent and standing blood pressures were reduced (P < 0.01 or less) during monotherapy with nitrendipine and acebutolol, but the magnitude of blood pressure reduction was greater (P < 0.05 or less) during nitrendipine dosing. Pulse rate decreased (P < 0.01) during acebutolol whereas nitrendipine induced a nonsignificant increase. Both treatments induced no changes in serum electrolytes, creatinine, urea, uric acid, lipids, plasma renin activity, and plasma and urinary aldosterone. The overall incidence of side effects was similar with both treatments but four patients discontinued nitrendipine because of headache. The addition of mefruside to nitrendipine or acebutolol produced a further fall of blood pressure in patients not controlled with monotherapy. Monotherapy with nitrendipine or acebutolol offers an effective, safe first-line antihypertensive treatment in blacks entered in this study; with the described dosages and therapeutic schedule, nitrendipine was somewhat more effective than acebutolol. Clinical Pharmacology and Therapeutics (1987) 41, 45–54; doi:10.1038/clpt.1987.7

21 citations


Journal ArticleDOI
TL;DR: Actuely administered felodipine was a potent dilator of systemic but not of pulmonary arterioles, it stimulated the sympathetic nervous system, and reduced left ventricular filling pressure.
Abstract: Oral administration of felodipine to 10 patients with mild essential hypertension acutely reduced systemic vascular resistance (SVR) by 40% after 30 min. The change in SVR was significantly related to age (r=−0.74). The reduction in the intraarterially measured brachial artery pressure was limited to 15/13 mmHg, due to a rise in cardiac output (CO). The tachycardia was sustained for 90 min, as was an elevation of plasma noradrenaline. There was a transient increase in stroke volume, associated with a reduction in pulmonary capillary wedge pressure, which was at least partly due to a reduced intravascular volume. In contrast to SVR, pulmonary vascular resistance was not affected by felodipine. Addition of intravascular metoprolol after 90 min decreased HR and CO and augmented SVR. The felodipine-induced rise in plasma renin activity (PRA) of 100% was completely reversed by metoprolol. Plasma angiotensin II (PA II) rose by 15% during felodipine, whereas plasma aldosterone concentration (PAC) was not affected. Thus, actuely administered felodipine was a potent dilator of systemic but not of pulmonary arterioles, it stimulated the sympathetic nervous system, and reduced left ventricular filling pressure. The rise in plasma renin did not result in a higher plasma aldosterone level, due partly to reduced generation of angiotensin II.

21 citations


Journal ArticleDOI
TL;DR: The higher left ventricular mass of female runners is not associated with changes of systolic and diastolic LV function, and the unchanged ratio of the peak velocities of LV filling during atrial contraction and early filling indicates that LV distensibility is unaltered in the athletes.
Abstract: Nine female runners and 9 matched control subjects were investigated with echocardiography and Doppler velocimetry to assess cardiac structure and systolic and diastolic left ventricular (LV) function at rest. LV mass was considerably larger in the athletes (171 vs 123 g; P less than 0.01). Minute distance, the Doppler index of cardiac output, was similar in runners and controls; the lower heart rate (P less than 0.01) of the athletes was associated with a higher stroke distance (P less than 0.05). The latter could be attributed to a larger end-diastolic LV internal diameter (46 vs 43 mm; P less than 0.05); wall stress and the various indices of systolic LV function were not different between runners and controls. Early diastolic LV function, estimated from the velocity of LV relaxation and the LV inflow pattern, and late diastolic function, assessed by Doppler velocimetry, were similar in runners and controls. The unchanged ratio of the peak velocities of LV filling during atrial contraction and early filling (0.49 vs 0.44; NS) indicates that LV distensibility is unaltered in the athletes. In conclusion, the higher left ventricular mass of female runners is not associated with changes of systolic and diastolic LV function.

20 citations


Journal ArticleDOI
TL;DR: During ketanserin administration, LDL-C decreased, whereas HDL-C and the HDL/LDL-C ratio increased and no significant effect in serum total cholesterol occurred, whereas during propranolol administration, nosignificant effect was observed.
Abstract: The effect of ketanserin and propranolol on the serum total cholesterol (TC), and high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) cholesterol was studied in hypertensive patients treated for 3 months. During ketanserin administration, LDL-C decreased, whereas HDL-C and the HDL-C/LDL-C ratio increased and no significant effect in serum total cholesterol occurred. During propranolol administration, no significant effect was observed on serum total cholesterol, HDL-C and LDL-C, but the ratio of HDL-C/LDL-C increased. Intergroup comparison showed a greater increase in HDL-C (p less than 0.05) and in the HDL-C/LDL-C ratio (p less than 0.01) in the ketanserin group as compared with the propranolol group.


Journal ArticleDOI
TL;DR: Despite the poor agreement in absolute results between the two methods, aortic Doppler velocimetry reflects the acute haemodynamic changes induced by felodipine and metoprolol in a group of hypertensive patients.
Abstract: In order to evaluate the use of Doppler echocardiography in the assessment of the haemodynamic effects of antihypertensive drugs, the acute haemodynamic response to felodipine and additional administration of metoprolol after 90 min was assessed in 10 hypertensive patients, by using both the Fick method and Doppler blood flow velocimetry in the ascending aorta. Intrabrachial artery pressure was significantly reduced by the treatment. Both the Fick and Doppler estimates of cardiac output (CO) rose significantly with felodipine and reached their highest values after 30 min, 45 +/- 8% (s.e.m.) and 58 +/- 7%, respectively. The felodipine-induced increase of heart rate (HR) persisted for 90 min, but the increase of stroke volume was only transient. Metoprolol brought CO and HR back to control levels. The felodipine- and metoprolol-induced changes of CO and stroke volume (SV) from control were on average not different between the observations with the Fick and the Doppler techniques throughout the study. As for the absolute values (control period), the Doppler measurement under-estimated SV (10 ml) and CO (1.1 l/min) in comparison with the Fick method, and the limits of agreement (mean difference +/- 2 s.d.) between both methods were 42 and -22 ml for stroke volume and 3.4 and -1.2 l/min for CO. In conclusion, despite the poor agreement in absolute results between the two methods, aortic Doppler velocimetry reflects the acute haemodynamic changes induced by felodipine and metoprolol in a group of hypertensive patients. The technique should facilitate the study of haemodynamic effects of drugs in man.

Journal Article
TL;DR: Whether they are effective hypotensives in the elderly, whether their effects are age-related, and what effects, if any, do they have on morbidity and mortality in geriatric hypertension are addressed.
Abstract: Angiotensin-converting enzyme inhibitors are gaining acceptance as safe and effective agents for treatment of hypertension. Data on their use specifically in elderly hypertensives, however, are limited. Addressed in this review of the available literature are the questions whether they are effective hypotensives in the elderly, whether their effects are age-related, and what effects, if any, do they have on morbidity and mortality in geriatric hypertension.

Journal ArticleDOI
01 Jan 1987-Drugs
TL;DR: Oral administration of felodipine to 10 patients with mild essential hypertension acutely reduced the brachial artery pressure by 15/13mm Hg and the tachycardia which occurred was sustained for 90 minutes together with an elevated plasma noradrenaline concentration.
Abstract: Oral administration of felodipine to 10 patients with mild essential hypertension acutely reduced the brachial artery pressure by 15/13mm Hg. The tachycardia which occurred was sustained for 90 minutes together with an elevated plasma noradrenaline concentration. Addition of intravascular metoprolol after 90 minutes decreased heart rate. The felodipine-induced increase of plasma renin activity (100%; p < 0.001) was completely reversed by metoprolol. Plasma angiotensin II (PA II) rose by 15% (p < 0.05) during felodipine, whereas plasma aldosterone concentration was not significantly affected.

Journal Article
TL;DR: The long-term effect of intraerythrocyte sodium concentration decreased and red cell ouabain-sensitive 86Rubidium-uptake increased during dietary sodium restriction and repletion suggests either the involvement of a mechanism which can only be slowly reversible or a mechanisms which is irreversible so that normalization takes place only when new red cells are released into the circulation.
Abstract: Erythrocyte concentrations and fluxes of sodium and potassium were investigated in normal white male subjects during dietary sodium restriction and repletion, each period lasting for 16 weeks. Intraerythrocyte sodium concentration decreased and red cell ouabain-sensitive 86Rubidium-uptake increased during dietary sodium restriction while no significant changes were observed in the total, furosemide-resistant and furosemide-sensitive sodium-efflux and the sodium, lithium-countertransport. The decrease in intraerythrocyte sodium concentration could have resulted from the observed increase in sodium, potassium-ATPase pump activity. The latter increase could have been secondary to the early decrease in a digitalis-like plasma inhibitor and the later increase could have been facilitated by the late rise in the intracellular adenosine triphosphate concentration, which is the energy supplier for this pump. During the subsequent first month of sodium repletion intraerythrocyte sodium concentration remained low. Red cell ouabain-sensitive 86Rubidium-uptake and adenosine triphosphate concentration remained elevated and returned to baseline only after 16 weeks. This long-term effect suggests either the involvement of a mechanism which can only be slowly reversible or a mechanism which is irreversible so that normalization takes place only when new red cells are released into the circulation.


Journal ArticleDOI
TL;DR: This test could be used as a tool to measure the degree of serotonin inhibition, at least at the platelet level, provided that the pH is controlled in the in vitro assay.
Abstract: The mechanism of the hypotensive action produced by ketanserin during chronic treatment in humans remains unknown. In contrast to previous reports, recent data show that ex vivo inhibition of the serotonin-induced platelet aggregation can be demonstrated in men during chronic ketanserin administration, provided that the pH is controlled in the in vitro assay. This test could be used as a tool to measure the degree of serotonin inhibition, at least at the platelet level.



Journal Article
TL;DR: The radioimmunoassay of alpha-atrial natriuretic peptide in human plasma and its application in normal subjects under various postural conditions was shown to be reproducible as indicated by the low within- and between-assay coefficients of variation.
Abstract: The present paper describes a radioimmunoassay, in conjunction with an extraction procedure on octadecasilyl silica cartridges, of alpha-atrial natriuretic peptide in human plasma and its application in normal subjects under various postural conditions. The sensitivity of this assay is 1.96 pg/ml. The plasma concentrations of alpha-atrial natriuretic peptide in 18 normal male subjects ranged from 10 to 55 pg/ml. This assay was shown to be reproducible as indicated by the low within- and between-assay coefficients of variation. The plasma alpha-ANP concentration decreased during prolonged storage of the plasma at -20 degrees C or -80 degrees C and its level is also lower in hemolyzed plasma samples. The plasma alpha-ANP concentration is similar in standing and supine position but rose significantly when the subjects were tilted 20 degrees head-down.