Data/hora: 03/06/2024 01:35:59

Provedor de dados: | 56
País: | Brazil
Título: | Diurnal variation of vascular diameter and reactivity in healthy young men
Autores: | Bau,P.F.D.; Bau,C.H.D.; Naujorks,A.A.; Rosito,G.A.; Fuchs,F.D.
Data: | 2008-06-01
Ano: | 2008
Palavras-chave: | Cardiovascular risk factor; Circadian rhythm; Brachial artery; Vasoconstriction; Vascular biology.
Resumo: | 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 &lt; 0.001). FMD values did not change significantly during the day, while NFMD increased more at 7 am (18.5 ± 1.1%), when compared to 15.5 ± 0.9% at 10 pm and 15.5 ± 0.9% 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.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000600011
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2008005000012
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.41 n.6 2008
Fonte: | info:eu-repo/semantics/openAccess