Haemorheologic alterations in hypertensive patients (dipper and no dipper)

geneous patient group (n 5420). Morning surge was defined as the difference between mean blood pressure and heart rate values in the four hours before and after rising. Morning surge was regressed on difference in mean (log transformed) activity for the same two periods. The presence or absence of concomitant b -blocker therapy was added to the regression, which was also adjusted for age, gender, clinic BP, and other antihypertensives. Of the 192 patients on antihypertensives; 87 were taking b -blockers. Use of b -blockers was significantly associated with a smaller morning surge in systolic blood pressure and heart rate on physical activity compared to those on no antihypertensive therapy. The use of other antihypertensives also reduced the magnitude of the morning surge, but this difference was not significant. b -blockers significantly reduce the magnitude of the morning surge of systolic blood pressure and heart rate in response to physical activity. These agents may have an advantage in the prevention of the morning excess of acute cardiovascular events. Key Words: Beta-blockers; morning surge; ambulatory blood pressure monitoring; physical activity C050 HAEMORHEOLOGIC ALTERATIONS IN HYPERTENSIVE PATIENTS (DIPPER AND NO DIPPER) C. Moreira, C. Saldanha, P. Alcaˆntara, C. Alcaˆntara, J. BrazNogueira, J. Martins e Silva. Medicine I Depar./Bioquimica fisiolo´gica Inst.-Hosp. St a Maria/Faculdade de Medicina de Lisboa-Portugal The 24 hours ABPM has allowed the discrimination of hypertensive patients in dippers and non-dippers. Being the last ones associated with a higher number of cardiac and vascular repercussions. The objective of the present work is to evaluate the haemomeologic alterations in hypertensive patients and to determine if there are differences of haemorheologic parameters between these two groups. A population of 73 patients with essential hypertension, without another pathology, was studied. Blood pressure was evaluated using one device Space Lab 90027. The nocturnal and diurnal period was determined on the basis of the daily profile of the patient. It was determined erythrocyte aggregation, fibrinogen, erythrocyte filtration and plasma viscosity. The statistical model was the t-Student for the comparison of the two groups. We considered significant values of p , 0,01 (“two-tailed significant”). The dippers had 49 patients and the non-dippers 24 patients. There were no differences in the ages and sex between the two groups. There were significant differences in the level of fibrinogen (non-dippers 389.0 6145.2 and dippers 256.4 6 45.7, p ,0,01), of plasma viscosity (non-dippers 1.35 60.07 and dippers 1.20 60.06, p ,0,01), and erythrocyte filtration (non-dippers 12.94 63.17 and dippers 14.95 68.5, p ,0,01). There were no differences in erythrocyte aggregation (nondippers 14.66 64.59 and dippers 14.62 63.8, p 2ns) and there was a significant correlation between the fibrinogen and plasma viscosity (r 50,79, p ,0,01). The non-dippers hypertensive patients had higher values of fibrinogen, plasma viscosity and erythrocyte filtration. These findings might be related with the structural alterations (cardiac and vascular) found in this group. Key Words: ABPM; haemorheology; hypertension complications C051 AMBULATORY BLOOD PRESSURE MONITORING IN CHILDREN AND ADOLESCENTS B. Grunfeld*, M. Bonanno, M. Romo, L. Rabinovich, R. Simsolo*. Hospital de Nin˜os R. Gutierrez. Buenos Aires, Argentina Ambulatory blood pressure monitoring (ABPM) was recorded in 396 children and adolescents (5 to 18 years old) with an auscultatory device (Suntech, Accutracker II). ABPM was recorded during daytime at 20 minute intervals and during nightime at 45 minute intervals. Asleep blood pressures were calculated according to each subject record. All subjects had their blood pressure measured at the clinic 3 times and the average was considered for comparisons. Asleep blood pressures and heart rates decreased in all subjects: systolic BP 13 60.6%, diastolic BP 19 60.7% and heart rate 18 60.7%. ABPM 50th Percentile for age was higher than Task Force 50th P up to 16 years old in both sexes. ABPM 95th percentiles for height were: females 110–129 cm: 113/68 mm Hg; 130–149 cm: 125/75 mm Hg; 150–170 cm: 137/78 mm Hg. Males 110–129 cm: 123/71 mm Hg, 130–149 cm: 119/68 mm Hg, 150–170 cm: 137/74 mm Hg and .171 cm: 133/78 mm Hg. White coat phenomenon was observed starting at 11 year old in females and 13 year old in males. Key Words: Ambulatory blood pressure; children; adolescents; white coat phenomenon C052 HOME BLOOD PRESSURE (BP) MEASUREMENT USING B.P. BRAUN VITALSCAN MONITOR H. Nolly*, M. Romero, A. Nolly and M. Nolly. Lab. of Experimental Hypertension, School of Medicine, Mendoza, Argentina The accurate measurement of arterial blood pressure (BP) is essential for the diagnosis and treatment of hypertension. The development of new automated equipments of measurements that provide reliable determinations of blood pressure should be valuable in the assessment of hypertension not only in the clinic but also in the home for selfmonitoring. Objective: The objective of this study was to determine the accuracy of the Braun Vital-Scan (BVS) blood pressure monMorning surge outcome b -blockers vs. no antihypertensives (11 log unit) Std error p-value SBP 23.42 1.70 0.045 DBP 20.17 1.28 0.9 HR 25.81 1.26 0.0001 228A ASH XV ABSTRACTS AJH–APRIL 2000–VOL. 13, NO. 4, PART 2