Cardiovascular mortality in hypertensive men according to presence of associated risk factors.

To evaluate the risk of cardiovascular disease (CVD) mortality in hypertensive men according to the presence of associated risk factors (ARFs). The population was composed of 29 640 normotensive men without ARFs (reference group) and 60 343 hypertensive men (with and without ARFs) who had a standard health checkup at the Centre d'Investigations Préventives et Cliniques between 1978 and 1988. Mortality data for a mean period of 14 years were analyzed. The following ARFs were considered: total cholesterol >/=2.5 g/L, personal history of diabetes, smoking (current smokers), body mass index >28 kg/m(2), and heart rate >80 bpm. CVD risk related to the presence of isolated hypertension (assessed in hypertensive subjects without ARFs versus the reference group) increased linearly from 15% at the age of 30 years to 134% at the age of 80 years. In hypertensive subjects, one additional ARF increased CVD risk by 56% (47% to 65%, P<0.01) in younger subjects but only by 4% (-8% to 17%, P=NS) in older subjects. The role of hypercholesterolemia and tobacco smoking in CVD mortality was significantly higher in hypertensive subjects aged <55 years than in hypertensive subjects aged >/=55 years (P<0.01), whereas the roles of tachycardia and obesity were not affected by age. In younger hypertensive subjects, evaluation of CVD risk and therapeutic strategies should target ARFS: In older subjects, the presence of high blood pressure levels seems to be the major determinant of CVD risk.

Changes in arterial structure and function under trandolapril-verapamil combination in hypertension.

BACKGROUND AND PURPOSE: Converting enzyme inhibition and calcium blockade alter large arteries in hypertension. However, the heterogeneity of the response according to the site of cardiovascular measurements has never been investigated. METHODS: In a double-blind study, we compared for 180 days 3 hypertensive patient groups treated with verapamil, trandolapril, or their combination. Using echo-Doppler technique and applanation tonometry, we independently measured mean pressure, local pulse pressure, arterial diameter, and distensibility at 3 arterial sites (brachial and common carotid arteries and abdominal aorta), as well as cardiac and carotid wall structure. RESULTS: Mean and pulse pressure decreased significantly to a greater extent with the drug combination. Regarding arterial and cardiac hemodynamics, significant and similar changes were noted in the 3 groups: decreases in abdominal aorta and carotid but not brachial diameter; increases in carotid artery, abdominal aorta, and brachial distensibility even after adjustment to mean blood pressure reduction; and more substantial regression of cardiac mass than carotid wall thickness. CONCLUSIONS: This study shows that both compounds and more significantly combination therapy decreased mean and pulse pressures measured independently and that the changes in diameter, thickness, and stiffness were influenced primarily by the site of cardiovascular measurements, resulting in a predominant increase in distensibility of muscular arteries, little change in carotid wall thickness, but a significant regression of cardiac hypertrophy.

Divergent effects of verapamil and amlodipine at rest and during exercise.

OBJECTIVE: To evaluate, in healthy volunteers, the effects of acute administration of two calcium antagonists with different pharmacological profiles, verapamil and amlodipine, on haemodynamics at rest and during exercise. SUBJECTS AND METHODS: Six healthy volunteers (aged 20-29 years) were randomly assigned to receive single oral doses of amlodipine (5 mg), slow-release verapamil (240 mg) or a placebo during a double-blind cross-over study. Systolic (SAP), diastolic and mean arterial pressures (measured using a cuff sphygmomanometer), heart rate (HR), cardiac index (CI, bioimpedance), rate-pressure product (SAP x HR), and noradrenaline and adrenaline plasma levels were measured at rest before drug administration, and at rest and during graded bicycle exercise (steps of 50, 100 and 150 W during 3, 3 and 4 min, respectively) started 3 h after drug administration. RESULTS: At rest arterial pressure, HR, rate-pressure product and catecholamine plasma levels did not change after verapamil or amlodipine administration, whereas CI significantly decreased after verapamil (from 3.9 +/- 0.4 to 3.3 +/- 0.4 l/min per m2) but not after amlodipine (3.9 +/- 0.3 and 4.1 +/- 0.5 l/m per m2) administration. During exercise the increases in SAP and HR were slightly but not significantly higher after amlodipine than after verapamil administration, rate-pressure product and CI were higher after amlodipine (22 +/- 1 x 10(3) mmHg x beats/min and 13 +/- 2 l/min per m2, respectively) than after verapamil (20 +/- 1 x 10(3) mmHg x beats/min and 10 +/- 2 l/min per m2, respectively) administration. Plasma levels of noradrenaline and adrenaline were similar at rest after each treatment and were slightly more increased after amlodipine administration during exercise. CONCLUSIONS: In contrast to amlodipine, verapamil induced a slight myocardial depressive effect at rest and did not potentiate the myocardial effects of the sympathetic stimulation induced by exercise. The myocardial action of verapamil is such as to induce some decrease in myocardial oxygen demand, both at rest and during exercise.

Enzyme electrode composed of the pyruvate oxidase from Pediococcus species coupled to an oxygen electrode for measurements of pyruvate in biological media.

Pyruvate oxidase from Pediococcus species was immobilized with gelatin and insolubilized in film form by tanning with glutaraldehyde. The film was fixed onto the tip of an oxygen electrode. The enzyme electrode was specific for pyruvate measurements. This electrode was sensitive to 0.1 mM and could be used up to a final pyruvate concentration of 2 mM. At each step of the enzymatic film preparation and assay 0.7 mM thiamine pyrophosphate, 10 microM flavin adenine dinucleotide, 5 mM Mg2+ and 10 mM phosphate buffer were necessary. A computerized probe allowed successive measurements every 3 min for more than 20 h with the same enzymatic film. The reproducibility for the same pyruvate concentration was 2% during 400 assays without special optimization. This enzyme electrode has many applications in basic (metabolism, enzymology) and applied (blood, yoghurt) research. Results obtained from assays carried out in yoghurt are presented.