Diagnóstico de hipertensäo arterial sistêmica: evidências de que os critérios contemporâneos devem ser revistos / Diagnosis of systemic hypertension: evidences that current criteria should be revised

Diversos comitês normativos em hipertensäo arterial recomendam considerar a média de várias aferiçöes da pressäo arterial com esfigmomanômetro para diagnosticar hipertensäo. Näo há consenso sobre o número de medidas a serem consideradas. OBJETIVO. Descrever o comportamento da pressäo arterial obtida em três dias diferentes, utilizando-se a média de seis aferiçöes para o diagnóstico de hipertensäo. MÉTODOS. No ambulatório de hipertensäo da Unidade de Farmacologia Clínica do Hospital de Clínicas de Porto Alegre, emprega-se a média de seis determinaçöes, obtidas em três dias diferentes, para diagnosticar e classificar a hipertensäo, exceto nos pacientes com valores muito baixos ou elevados nas duas primeiras aferiçöes. Cinqüenta e oito pacientes foram submetidos a essa rotina. RESULTADOS. As médias das pressöes sistólica (PS) e diastólica (PD) decresceram da primeira à sexta determinaçäo (ANOVA para medidas repetidas: F = 4,45, p = 0,001 para PS e F = 5,54, p < 0,001 para PD). Os pacientes foram divididos em grupos com PS e PD obtidas na primeira aferiçäo superiores e inferiores à média de todo grupo. A diminuiçäo de ambas as pressöes ao longo das seis aferiçöes ficou restrita aos grupos com valores da primeira determinaçäo superiores à média de todo o grupo (ANOVA: F = 8.03; p < 0,0001 para PS e F = 6,33, p < 0,0001 para PD). A regressäo à média e uma reaçäo de alerta inicial säo explicaçöes aventadas para esse fenômeno. CONCLUSÄO. Esses dados demonstram que o diagnóstico de hipertensäo arterial näo deve ser feito com base em uma única aferiçäo e sugerem que a recomendaçäo de diagnosticar hipertensäo severa baseando-se em altos valores das duas primeiras medidas pode classificar erroneamente alguns pacientes.

[Diagnosis of systemic hypertension: evidences that current criteria should be revised]. / Diagnóstico de hipertensão arterial sistêmica: evidências de que os critérios contemporâneos devem ser revistos.

UNLABELLED: It has been recommended to take the average of several blood pressure (BP) determinations with a sphygmomanometer to diagnose hypertension, but there is no agreement on the reading numbers. PURPOSE: Describing the behavior of BP readings taken in three different days to establish the classificatory BP in an outpatient hypertension clinic. METHOD: In the outpatient hypertension clinic of the Clinical Pharmacology Division of the Hospital de Clínicas de Porto Alegre, we use the mean of six readings taken in three different days to establish the classificatory blood pressure, except for those with very high or low values in the first day. In this report we describe the behavior of BP in 58 patients submitted to this routine. RESULTS: The mean of systolic (SBP) and diastolic (DBP) blood pressures decreased from the first to the 6th reading (ANOVA for repeated measurements: F = 4.45, P = 0.001 for SBP and F = 5.54, P < 0.001 for DBP). Afterward, the patients were classified into two groups according their first SBP and DBP reading. The decreasing in both SBP and DBP was confined to those with the first measurement in the upper half of the entire group (ANOVA: F = 8.03; P < 0.0001 for SBP and F = 6.33, P < 0.0001 for DBP). Regression to the mean and some reactiveness in the first day are possible explanations for this. CONCLUSION: These data corroborate that the hypertension diagnosis should not be based in an single blood pressure determination and suggest that the recommendation to diagnose severe hypertension based on high values in the first two readings could misclassify some patients.

Reliability of environmental, biological and health characteristics of infants from a developing country.

BACKGROUND: Although most epidemiological data are gathered by interviews, few studies ascertain their reliability. This study quantified inter-observer reliability of environmental, biological and health characteristics of underprivileged children, in a southern Brazilian state. METHODS: Five health care professionals who had received extensive standardized interview and observation training interviewed mothers and observed the home environments of a random sample of 102 children. A second interview was conducted by a sixth health professional who had received separate but identical training without the initial interviewer knowing a follow-up interview would be conducted. Data from the two independent interviews and observations were compared for agreement using the kappa statistic. RESULTS: There was excellent agreement (kappa > 0.75) for most of the household characteristics, such as type of walls, ceiling, floor and windows in spite of the diversity of buildings. Presence of the parents, number of people in the house-hold, age of the mother and health assistance were reliable as well. However, information about skin colour of the mother and the number of cracks in the house only reached fair agreement. CONCLUSIONS: These results showed that data gathered by observation and interviews generate accurate information about environmental, biological and health care characteristics. Those based on written information, such as birth date, were highly concordant.

PIP: In Brazil, data from a case control study of risk factors for pneumonia among low-income children less than 24 months old were used to quantify the reliability of inter-observer information about environmental, biological, and health characteristics of these children. Five experienced field workers who underwent training in role play, classroom lectures, discussions, and closely-supervised field practice interviewed the mothers of 102 children and observed their home environments. Another experienced professional, unknown to the other field workers, who received the same instructions as the others but independently of them conducted a second independent assessment three weeks after the initial assessment. All the interviewers were blind to the objective of this study. Even though the dwellings were quite diverse, the researchers found excellent agreement (kappa statistic 75) for most household characteristics (type of walls, presence and type of ceiling, type of floor, and presence, type, and number of windows in child's bedroom). Agreement was also good to excellent for presence of parents, number of people in the household, age of the mother, and history of previous pneumonia, hospitalization, and immunization. Agreement was relatively good when the number of cracks in the wall was 0 (0.76) or more than 20 (0.65) but not when it ranged from 1 to 19 (0.3-0.38). Agreement on skin color was more reliable when skin color was White or Black (0.77 and 0.78, respectively) than it was for mixed (0.63). Data based on written information yielded the most concordance while observation of sensitive risk factors (i.e., skin color and number of cracks [indicator for poor housing]) yielded the lowest concordance. These findings show that observation- and interview-collected data yield accurate information about environmental, biological, and health care characteristics.

The status of ethnopharmacology in Brazil.

Brazil is a country of interest to ethnopharmacology because of its great wealth of cultural and biological diversity. This paper describes relevant research activities in the areas of botany, chemistry, basic and clinical pharmacology, and discusses the key factors that shaped ethnopharmacology development in the country. Specific attention is given to analyzing ongoing attempts to include medicinal plant based formulations in the official health care system.

Effect of postnatal methylmalonate administration on adult rat behavior.

1. Methylmalonate (MMA) levels (2.0-2.5 mM) comparable to those of human methylmalonic acidemia were achieved in blood of young rats from the 5th to the 25th day of life by injecting the drug subcutaneously twice a day with an interval of 8 h. MMA doses ranged from 0.76 to 1.69 mumol/g body weight as a function of animal age. MMA-treated rats had normal body and brain weights. 2. Behavioral studies using aversive and nonaversive tasks were performed at 60 days of life. Motor activity was similar in MMA-treated and saline-treated controls. No differences in performance between these groups were identified in the shuttle-avoidance responses and in the inhibitory avoidance tasks. However, MMA-injected rats escaped footshock faster than the controls (1.22 +/- 0.11 vs 1.76 +/- 0.14 (mean +/- SEM) for 24 rats in each group (P less than 0.01)) suggesting that they may be hyperreactive to this stimulus. 3. In the open field, a nonaversive behavior task, MMA-injected rats, in contrast to control rats, presented no habituation. 4. Our results suggest that MMA by itself may impair central nervous system function, causing minor disabilities which result in specific learning deficiencies.

Effect of postnatal methylmalonate administration on adult rat behavior

Methylmalonate (MMA) levels (2.0-2.5 mM) comparable to those of human methylmalonic acidemia were achieved in blood of young rats from the 5th to the 25th day of life by of life by injecting the drug subcutaneously twice a day with an interval of 8h. MMA doses ranged from 0.76 to 1.69 *mol/g body weight as a function of animal age. MMA-treated rats had normal body and brain weights. Behavioral studies using aversive and nonaversive tasks were performaed at 60 days of life. Motor activity was similar in MMA-treated and saline-treated controls. No differences in performance between these groups were identified in the shuttle-avoidance responses and in the inhibitory avoidance tasks. However, MMA-injected rats escaped footshock faster than the controls (1.22 ñ 0.11 vs 1.76 ñ 0.14 (mean ñ SEM) for 24 rats in each group (P<0.01)) suggesting that they may be hyperreactive to this stimulus. In the open field, a nonaversive behavior task, MMA-injected rats, in contrast to control rats, presented no habituation. Our results suggest that MMA by itself may impair central nervous system function, causing minor disabilities which result in specific learning deficiencies

A simple simulated public speaking test for evaluating anxiolytic drugs.

1. We evaluated the feasibility of using a simulated public speaking (SPS) test to assess the activity of anxiolytic drugs. SPS was achieved by requesting subjects to present a speech to an audiocassette recorder. Thirty volunteers were randomly assigned to one of three groups treated with 10 mg diazepam, 10 mg buspirone or placebo, under double-blind conditions. One h after drug administration, subjective states were measured by the Visual Analogue Mood Scale (VAMS), the State-Trait Anxiety Inventory (STAI) and by a Bodily Symptoms Scale (BSS). Heart rate and blood pressure were also recorded. 2. SPS induced both physiological and subjective changes characteristic of anxiety. Moreover, diazepam attenuated experimentally induced increases in excitement (as measured by VAMS) and agitation (as measured by BSS). Therefore, SPS using an audiocassette recorder is sensitive to a prototypical anxiolytic and may thus be a useful test for evaluating putative anxiolytics. 3. No effect was observed with the new anxiolytic drug buspirone. However, the present negative result may be explained by clinical data indicating that patients may experience a longer lag period before the onset of the anxiolytic effect of buspirone.

A simple simulated public speaking test for evaluating anxiolytic drugs

We evaluated the feasibility of using a simulated public (SPS) test to assess the activity of anxiolytic drugs. SPS was achieved by requesting subjects to present a speech to an audiocassette recorder. Thirty volunteers were randomly assigned to one of three groups treated with 10 mg diazepam, 10 mg buspirone or placebo, under double-blind conditions. One h after drug adminsitration, subjective states were measured by the Visual Analogue Mood Scale (VAMS), the State-Trait Anxiety Inventory (STAI) and by a Bodily Symptoms Scale (BSS). Heart rate and blood pressure were also recorded. SPS induced both physiological and subjective changes characteristic of anxiety. Moreover, diazepam attenuated experimentally induced increases in excitement (as measured by VAMS) and agitation (as measured by BSS). Therefore, SPS using an audiocassette recorder is sensitive to a prototypical anxiolytic and may thus be a useful test for evaluating putative anxiolytics. No effect was observed with the new anxiolytic drug buspirone. However, the present negative result may be explained by clinical data indicating that patients may experience a longer lag period before the onset of the anxiolytic effect of buspirone

Diminished concentrations of ganglioside N-acetylneuraminic acid (G-NeuAc) in cerebellum of young rats receiving chronic administration of methylmalonic acid.

Sustained levels of methylmalonate comparable to those of human methylmalonic acidemia were achieved in the blood of young rats from the 5th till the 25th day of life by injecting them subcutaneously with buffered methylmalonic acid (MMA) twice a day at 8-h intervals. A matched group of rats (controls) was treated with saline. The animals were weighed and killed by decapitation at 25 days of age. Cerebellum and cerebrum were weighed and their contents of protein, DNA and ganglioside N-acetylneuraminic acid (G-NeuAc), as well as the protein/DNA ratio determined. Body weight, cerebral and cerebellar weight did not differ in both groups. The concentrations of protein, DNA and the protein/DNA ratio were also similar in the experimental and control groups. The results indicate that MMA per se does not interfere with the appetite of the animals and does not affect cellular proliferation and growth in cerebrum and cerebellum. We also found that G-NeuAc concentration is significantly reduced in the cerebellum. Therefore, since a deficit of an important component of brain closely related to the dendritic surface (synaptogenesis) occurs in MMA-treated rats, it is tempting to speculate whether this alteration may be associated or even partly responsible for the mental retardation in patients affected by methylmalonic acidemia.

Effect of sodium intake on blood pressure, serum levels and renal excretion of sodium and potassium in normotensives with and without familial predisposition to hypertension.

1. Seventeen normal volunteers aged 19 to 22 were randomly subjected, in a trial of crossover design, to three distinct regimens of sodium chloride intake: high (16 to 20 g), normal (8 to 12 g) and low (0.5 to 1 g). Each regimen lasted nine days, with determination of blood pressure and heart rate (in the supine position and after sudden rising), body weight, and urinary output of creatinine, sodium and potassium on the third, sixth and ninth days. In addition, plasma levels of creatinine, sodium and potassium were determined on the ninth day so that sodium and potassium clearance and fractional excretion could be calculated. 2. Eleven of the volunteers had a family history of hypertension. Compared to the six without such a history, these subjects showed: 1) higher supine systolic blood pressure on the third day of sodium overload (124.7 +/- 3.0 vs 112.3 +/- 2.9 mmHg, P less than 0.02); 2) higher supine diastolic blood pressure on the third day of sodium overload (76.5 +/- 2.8 vs 64.5 +/- 4.3 mmHg; P less than 0.05); 3) higher supine diastolic blood pressure on the sixth day of sodium overload (73.7 +/- 2.3 vs 63.8 +/- 3.2 mmHg, P less than 0.05); 4) lower supine heart rate on the ninth day of sodium overload (61.0 +/- 3.1 vs 72.7 +/- 4.6, P less than 0.05), and 5) lower plasma potassium on the ninth day of sodium overload (4.10 +/- 0.05 vs 4.28 +/- 0.06 mEq/l, P less than 0.05). 3. These results suggest that normal individuals whose familial history places them at risk for the development of hypertension differ from those not at risk during their adaptation to sodium load by suffering a transient elevation of blood pressure within a few days of the increase in load. The low levels of plasma potassium observed in these volunteers after a period of sodium load may be due to the operation of different renal mechanisms of sodium excretion in this group, leading to increased kaliuresis, and may explain the high vascular reactivity of such individuals.