The corporate bias and the molding of prescription practices: the case of hypertension

Drug management of hypertension has been a noticeable example of the influence of the pharmaceutical industry on prescription practices. The worldwide leading brands of blood pressure-lowering agents are angiotensin receptor-blocking agents, although they are considered to be simply substitutes of angiotensin-converting enzyme (ACE) inhibitors. Commercial strategies have been based on the results of clinical trials sponsored by drug companies. Most of them presented distortions in their planning, presentation or interpretation that favored the drugs from the sponsor, i.e., corporate bias. Atenolol, an ineffective blood pressure agent in elderly individuals, was the comparator drug in several trials. In a re-analysis of the INSIGHT trial, deaths appeared to have been counted twice. The LIFE trial appears in the title of more than 120 reproductions of the main and flawed trial, as a massive strategy of scientific marketing. Most guidelines have incorporated the corporate bias from the original studies, and the evidence from better designed studies, such as the ALLHAT trial, have been largely ignored. In trials published recently corporate influences have touched on ethical limits. In the ADVANCE trial, elderly patients with type 2 diabetes and cardiovascular disease or risk factors, allocated to placebo, were not allowed to use diuretic and full doses of an ACE inhibitor, despite the sound evidence of benefit demonstrated in previous trials. As a consequence, they had a 14 percent higher mortality rate than the participants allocated to the active treatment arm. This reality should be modified immediately, and a greater independence of the academy from the pharmaceutical industry is necessary.

Diurnal variation of vascular diameter and reactivity in healthy young men

The higher incidence of cardiovascular events in the morning is accompanied by an increased vascular tone. However, there are few published studies designed to evaluate the diurnal variation of vascular and endothelial parameters in healthy subjects. In the present investigation, we evaluated the diurnal variation in brachial artery diameter (BAD), flow-mediated dilation (FMD) and endothelium-independent dilation (NFMD) in a homogeneous sample of healthy non-smoker young men. Fifty subjects aged 20.8 ± 0.3 years (range: 18 to 25 years) were investigated by brachial artery ultrasound. Exclusion criteria were female gender and evidence of clinically significant health problems, including obesity. Volunteers were asked to rest and avoid fat meals as well as alcoholic beverages 48 h before and until completion of the evaluations. BAD, FMD and NFMD were measured at 7 am, 5 pm, and 10 pm and tested by repeated measures ANOVA. BAD was smaller at 7 am (mean ± SEM, 3.8 ± 0.1 mm) in comparison with 5 pm (3.9 ± 0.1) and 10 pm (4.0 ± 0.1 mm; P < 0.001). FMD values did not change significantly during the day, while NFMD increased more at 7 am (18.5 ± 1.1 percent), when compared to 15.5 ± 0.9 percent at 10 pm and 15.5 ± 0.9 percent at 5 pm (P = 0.04). The physiological state of vasoconstriction after awakening, with preserved capability to dilate in the morning, should be considered to be part of the healthy cardiovascular adaptation before considering later life risk factors and endothelial dysfunction.

Familial predisposition to hypertension and the association between urinary sodium excretion and blood pressure in a population-based sample of young adults

The reasons for the inconsistent association between salt consumption and blood pressure levels observed in within-society surveys are not known. A total of 157 normotensive subjects aged 18 to 35 years, selected at random in a cross-sectional population-based survey, answered a structured questionnaire. They were classified as strongly predisposed to hypertension when two or more first-degree relatives had a diagnosis of hypertension. Anthropometric parameters were obtained and sitting blood pressure was determined with aneroid sphygmomanometers. Sodium and potassium excretion was measured by flame spectrophotometry in an overnight urine sample. A positive correlation between blood pressure and urinary sodium excretion was detected only in the group of individuals strongly predisposed to hypertension, both for systolic blood pressure (r = 0.51, P<0.01) and diastolic blood pressure (r = 0.50, P<0.01). In a covariance analysis, after controlling for age, skin color and body mass index, individuals strongly predisposed to hypertension who excreted amounts of sodium above the median of the entire sample had higher systolic and diastolic blood pressure than subjects classified into the remaining conditions. The influence of familial predisposition to hypertension on the association between salt intake and blood pressure may be an additional explanation for the weak association between urinary sodium excretion and blood pressure observed in within-population studies, since it can influence the association between salt consumption and blood pressure in some but not all inhabitants.

Associaçäo entre diferentes indicadores de obesidade e prevalência de hipertensäo arterial / The association between different measurements of obesity and the prevalence of hypertension

OBJETIVO - Determinar a associaçäo entre índice de massa corporal (IMC), índice cintura-quadril e cintura com a prevalência de hipertensäo arterial (HAS) em amostra representativa de 1088 adultos de Porto Alegre, Brasil. MÉTODOS - Foram considerados hipertensos indivíduos com pressäo sistólica (PAS) 'maior ou igual' 160mmHg ou diastólica (PAD) 'maior ou igual' 95mmHg e definidos como obesos aqueles com IMC 'maior ou igual' 27kg/m², ou com razäo cintura/quadril 'maior ou igual'0,95 (homens) e 'maior ou igual'0,80 (mulheres) ou com cintura 'maior ou igual 96cm (homens) e 92 'maior ou igual'(mulheres). RESULTAODS - A obesidade aferida pelo IMC associou-se com prevalência de HAS em ambos sexos (RR 1,9, IC 1,0 - 3,2 masculino; RR 2,2, IC 1,3 - 3,8 feminino). Os outros índices associaram-se, significativamente, apenas nas mulheres. CONCLUSÄO - IMC 'maior ou igual' 27,0kg/m² associou-se mais, consistentemente com o risco de HAS. A magnitude similar das associaçöes dos demais indicadores demostram sua utilidade na avaliaçäo do risco para a hipertensäo.

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.

Infeccao hospitalar: apresentacao de um sistema operacional de controle epidemiologico. / Hospitalar infection: report of an operational system for epidemiological control

A aquisicao de infeccao no hospital soma-se a nosologia que determinou a internacao do paciente, refletindo-se em aumento de morbidade, mortalidade e custos. O presente trabalho apresenta um sistema operacional de coleta e tabulacao de dados relativos a infeccao no Hospital Nossa Senhora da Conceicao de Porto Alegre, o qual permite uma adequada quantificacao do problema e do resultado das medidas de controle propostas