Effect of 12-Week Resistance Training with Blood Flow Restriction on Arterial Stiffness in Octogenarian People with Low Gait Speed: A Randomized Controlled Trial

Research Article

Phys Med Rehabil Int. 2023; 10(3): 1218.

Effect of 12-Week Resistance Training with Blood Flow Restriction on Arterial Stiffness in Octogenarian People with Low Gait Speed: A Randomized Controlled Trial

Marcelo Rodrigues dos Santos, PhD¹; Samuel Amorim, MSc¹; Alexandra Passos Gaspar, PhD¹; Raphael Mendes Ritti-Dias, PhD²; Gabriel Grizzo Cucato, PhD³; Luciana Diniz Nagem Janot De Matos, PhD¹*

1Hospital Israelita Albert Einstein, São Paulo, Brazil

2Postgraduate Program in Rehabilitation Science, Universidade Nove de Julho, Sao Paulo 01525-000, Brazil

3Faculty of Health and Life sciences, Northumbria University, Newcastle NE1 8ST, UK

*Corresponding author: Luciana Diniz Nagem Janot De Matos, PhD Hospital Israelita Albert Einstein Avenida Albert Einstein 627, Bloco D, 3 Andar São Paulo, 05651901 Brazil. Tel: +55 (11) 2151-1100 Email: luciana.matos@einstein.br

Received: July 26, 2023 Accepted: August 23, 2023 Published: August 30, 2023

Abstract

Aim: Aging is associated with loss of muscle mass and strength. Low-Intensity Resistance Exercise with Moderate Blood-Flow Restriction (LIRE-BFR) improves these outcomes, but the long-term effect on arterial stiffness and safety in elderly people with low gait speed is unknown.

Methods: This is a parallel, randomized controlled clinical study with 12 older adults (3 men; 9 women; 84.0 [76.0; 87.5] years old) who completed a 12-week training of traditional resistance exercise (TRE; n=6) or LIRE-BFR (n=6). All participants were evaluated at baseline and after 12 weeks by carotid-femoral aortic Pulse Wave Velocity (PWV).

Results: After 12 weeks of interventions, PWV decreased in TRE group (-2.9 [-8.1; 2.4] m/s) and increased slightly in LIRE-BFR group (1.1 [-3.2; 5.3] m/s) but no differences were observed between the groups (p=0.21 for group; Hedge’s g: 0.52). Mean blood pressure was similar between TRE (86.2 [81.8; 90.9] to 85.8 [76.5; 96.3] mmHg) and LIRE-BFR (92.4 [82.1; 103.9] to 85.5 [79.2; 92.4] mmHg, p=0.462 for interaction). Gait speed increased significantly after 12 weeks in both groups (p<0.001 for time) with no differences between them (p=0.693 for groups).

Conclusions: Compared to TRE, LIRE-BFR increased PWV slightly, while gait speed increased similarly in both training modalities. Larger clinical trials including elderly people with low gait speed are needed to determine the clinical impact of these findings.

Keywords: Resistance training; Blood flow restriction; Vasodilation; Arterial stiffness; Elderly

Introduction

Aging is associated with loss of functional capacity, cardiovascular diseases, and frailty mainly in octogenarians. Exercise training is a non-pharmacological evidence-based therapy to counteract these outcomes in the elderly population. However, elderly people over 80 years of age are underrepresented in randomized clinical trials involving exercise training.

Moderate-intensity aerobic physical activity and muscle-strengthening activities at moderate or greater intensity are recommended for older adults [1]. However, frail elderly people often face major barriers to physical activity including cognitive decline, discomfort and pain, fear of injury or falling, past sedentary lifestyle, insufficient understanding of physical activity, and environmental restriction [2].

Frail octogenarians may benefit from an exercise training approach that addresses their limitations. For instance, physical activity guideline recommends resistance training to improve muscle strength in older persons at the intensity of 40%-50% of the 1-repetition maximum (1-RM) [1]. Lower intensity of resistance training (20%-50% of the 1RM) in older adults may improve power. Although these evidence-based recommendations can include frail population, additional studies are needed to provide definitive guidelines regarding exercise prescription in older individuals with frailty and low gait speed.

In healthy young adults, low-intensity resistance exercise with Blood Flow Restriction (BFR) improved muscle mass and strength similarly when compared to traditional high-intensity strength training [3,4]. Typically, BFR training uses low loads (20%-30% of 1RM) [5], which may be more appropriate to octogenarians, especially those who are sarcopenic. BFR combines resistance exercise with blood flow restriction on the limbs to reduce blood flow. Flow restriction-induced ischemia activates different mechanisms and has been associated with up- and down-regulated muscle genes expression, angiogenesis, muscle strength, and muscle hypertrophy [6-8]. Additionally, BFR has been proposed in cardiac rehabilitation of frail patients [9]. However, cardiovascular safety and possible harms are not known.

Recently, we demonstrated the acute effect of a single bout of Traditional Resistance Exercise (TRE) and BFR on arterial stiffness in older people with a mean age of 82 years with low gait speed [10]. TRE and BFR induced similar increases in Pulse Wave Velocity (PWV) without any adverse event. Previous study showed that four months of TRE reduces central arterial compliance in healthy men [11], but this association was not observed in middle-aged participants (=40 years old) [12]. Therefore, the clinical significance of this mild resistance training-induced arterial stiffness is unclear, particularly in older persons.

Here, we described a proof-of-concept study to determine the chronic effect of 12 weeks of BFR on arterial stiffness in elderly people with low gait speed. Our hypotheses in this non- inferiority randomized study are that BFR elicits similar increase in gait speed and muscle strength as conventional resistance training with no detrimental effect on arterial stiffness.

Methods

Trial Design

This is an open label, non-inferiority, parallel, randomized controlled trial. The protocol of this study was published previously [13] and registered on ClinicalTrials (NCT03272737). The study was approved by the institutional review board (CAAE: 56798316.4.0000.0071) and all participants provided their informed written consent before enrollment. We followed the CONSORT checklist for randomized clinical trials [14].

Participants

We conducted the study from February 2018 through February 2020 at Hospital Israelita Albert Einstein, Sao Paulo, Brazil. Ninety-five older adults (>65 years old) were assessed for study eligibility from a list of patient records from the Hospital Israelita Albert Einstein.

Inclusion criteria were any adults (both sexes) with gait speed slower than 0.9 m/s. Adults were excluded from the study if their gait speed was greater than 0.9 m/s or any of the following was uncovered in their patient records or clinical examination: uncontrolled diabetes mellitus or peripheral neuropathy, symptomatic peripheral arterial disease, uncontrolled arterial hypertension (BP >160/100 mmHg), hypercholesterolemia (total cholesterol >220 mg/dL), infections within the past month, osteoarticular or neurological problems that prevented training, a history of anemia, cerebrovascular disease, or myocardial infarction within the last 6 months, a prior history of a deep-vein thrombosis, current usage of anticoagulants or double antiplatelet agents, a history of smoking within the past 6 months or cognitive impairment (Mini-Mental Status Exam <24). After screening, twelve older adults were included in the study (Figure 1).