Effects of Blood Flow Restriction Exercise on Hemodynamic and Cardiovascular Response in Hypertensive Subjects: a systematic review

Abstract Blood flow restriction (BFR) exercise is an effective approach for increasing muscle mass and muscle strength. However, it remains unclear if the magnitude of those positive adaptations will lead to similar responses for hemodynamic variables in hypertensive subjects. The present systematic review aimed to assess the effects of exercise with and without BFR on acute and chronic hemodynamic and cardiovascular responses in hypertensive subjects. Studies published between 2000 and 2019 were included. Randomized controlled trials (RCTs) and non-randomized trials (NRCTs) which evaluated hemodynamic and cardiovascular response in hypertensive subjects practicing exercise with BFR or those comparing hemodynamic and cardiovascular response during exercise with and without BFR were also eligible. A literature research of English and non-English-language articles for review was conducted across PubMed and Science Direct databases, including reference lists of relevant papers. Level of evidence was determined according to the criteria described by Oxford Center for Evidence-Based Medicine. In addition, risk of bias was assessed using the modified version of Downs and Black checklist. Four studies were included involving 60 participants; from those, three were NRCTs and one was a RCT. Three studies included in this review evaluated the effect of resistance training with and without BFR and only one the effect of aerobic exercise. The score on Downs and Black checklist was 11. The main findings were that the included patients’ characteristics were not clearly reported, and all the revised studies contained significant methodological limitations. Thus, all studies were classified as being of poor methodological quality. In addition, the evidence level provided in all the revised studies was level IIb only (i.e. poor-quality studies). Considering the limited available evidence, no definitive recommendation about BFR exercise in hypertensive subjects can be addressed due to the weak methodological design of the studies. Keywords: Resistance Training. Hypertension. Vascular Occlusion. Blood Flow Restriction. Resumo O exercicio fisico com restricao do fluxo sanguineo (RFS) e uma abordagem eficaz para o aumento da massa muscular e forca muscular. No entanto, ainda nao esta claro se a magnitude dessas adaptacoes positivas levara a respostas semelhantes para as variaveis hemodinâmicas e cardiovasculares em individuos hipertensos. A presente revisao sistematica objetivou avaliar os efeitos do exercicio fisico com e sem RFS sobre respostas hemodinâmicas e cardiovasculares agudas e cronicas em hipertensos. Estudos publicados entre 2000 e 2019 foram incluidos. Ensaios clinicos randomizados e nao-randomizados em que avaliaram a resposta hemodinâmica e cardiovascular em hipertensos que praticavam exercicio fisico com RFS ou aqueles que compararam a resposta hemodinâmica e cardiovascular durante o exercicio com e sem RFS tambem foram elegiveis. Uma pesquisa bibliografica de artigos em ingles e nao ingles para a presente revisao foi realizada nas bases de dados PubMed e Science Direct, incluindo listas de referencia de artigos relevantes. O nivel de evidencia foi determinado de acordo com os criterios descritos pelo Oxford Center for Evidence-Based Medicine. Alem disso, a qualidade dos artigos foi avaliada usando a versao modificada da lista de verificacao de Downs e Black. Foram incluidos quatro estudos envolvendo 60 participantes nesta revisao. Destes, tres eram ensaios clinicos nao randomizados e somente um era ensaio clinico randomizado. Tres estudos incluidos nesta revisao avaliaram o efeito do treinamento resistido com e sem RFS e apenas um avaliou o efeito do exercicio aerobico. A pontuacao na lista de verificacao de Downs e Black foi 11. Os principais achados foram que as caracteristicas dos pacientes incluidos nao foram claramente relatadas e todos os estudos revisados ​​continham limitacoes metodologicas significativas. Assim, todos os estudos foram classificados como de baixa qualidade metodologica. Alem disso, o nivel de evidencia fornecido em todos os estudos revisados ​​era apenas de nivel IIb (ou seja, estudos de baixa qualidade). Considerando as poucas evidencias disponiveis, nenhuma recomendacao definitiva sobre o exercicio fisico com RFS em individuos hipertensos pode ser abordada devido ao fraco desenho metodologico dos estudos. Palavras-chave: Treinamento Resistido. Hypertensao. Oclusao Vascular. Restricao do Fluxo Sanguineo.