INTRODUCTION: Exercise with an arm ergometer (EB) overcomes the main barrier to physical exercise in patients with Peripheral Artery Disease (PAD), leg pain during walking. Due to its aerobic nature, this type of exercise can cause systemic changes in the regulatory mechanisms of vasodilation. In other words, it provides vascular benefits in the most affected arterial beds in the PAD population. OBJECTIVE: To analyze local and systemic vascular responses, as well as cell signaling pathways after an EB exercise session in patients with PAD and their peers without PAD. METHODS: 24 patients with PAD and 24 individuals without PAD will be recruited, matched by sex and age. Participants will undergo two experimental sessions in approved order (EB and control). The EB session will consist of 15 cycles of 2 min of exercise with an intensity equivalent to 13-15 on the Borg scale of perceived exertion. Before and after the experimental sessions, the vascular function of the brachial and femoral arteries, blood indicators of vasodilation and calf muscle oxygenation will be evaluated. To analyze the acute effect between groups on cardiovascular parameters, a three-way analysis of variance will be performed, taking as factors disease (presence vs. absence), session (EB vs. Control) and time (pre vs. post). In all analyses, when a significant effect is selected, the Bonferroni or Newman-Keuls post-hoc test will be used. For all analyses, a value of P\<0.05 will be considered significant.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
24
Two conditions will be tested: Arm-cranking and control condition.
University Nove de Julho
São Paulo, São Paulo, Brazil
Calf Muscle Oxygen Saturation (%)
The parameters of calf muscle oxygenation will be collected using the non-invasive Near-Infrared Spectroscopy (NIRS) technique, with an NIRS spectrometer and a dedicated laptop computer. The NIRS sensor will be placed on the calf region, on the leg with the lower ankle brachial index, at the level of the largest calf circumference. The equipment will be programmed for continuous recording throughout the experimental session, covering the pre-exercise, during exercise with arm ergometer, and post-exercise periods.
Time frame: Just before, during 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 minutes of exercise, and after 10 minutes of exercise.
Change from baseline in vascular function post-exercise in the brachial and femoral arteries (%).
Vascular function will be measured in the supine position by the flow-mediated dilation (FMD) technique, through Doppler ultrasonography.
Time frame: Before and after 40 minutes of exercise.
Oxyhemoglobin (micromol)
The parameters of calf muscle oxygenation will be collected using the non-invasive Near-Infrared Spectroscopy (NIRS) technique, with an NIRS spectrometer and a dedicated laptop computer. The NIRS sensor will be placed on the calf region, on the leg with the lower ankle brachial index, at the level of the largest calf circumference. The equipment will be programmed for continuous recording throughout the experimental session, covering the pre-exercise, during exercise with arm ergometer, and post-exercise periods.
Time frame: Just before, during 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 minutes of exercise, and after 10 minutes of exercise.
Deoxyhemoglobin (micromol)
The parameters of calf muscle oxygenation will be collected using the non-invasive Near-Infrared Spectroscopy (NIRS) technique, with an NIRS spectrometer and a dedicated laptop computer. The NIRS sensor will be placed on the calf region, on the leg with the lower ankle brachial index, at the level of the largest calf circumference. The equipment will be programmed for continuous recording throughout the experimental session, covering the pre-exercise, during exercise with arm ergometer, and post-exercise periods.
Time frame: Just before, during 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 minutes of exercise, and after 10 minutes of exercise.
Total hemoglobin (micromol)
The parameters of calf muscle oxygenation will be collected using the non-invasive Near-Infrared Spectroscopy (NIRS) technique, with an NIRS spectrometer and a dedicated laptop computer. The NIRS sensor will be placed on the calf region, on the leg with the lower ankle brachial index, at the level of the largest calf circumference. The equipment will be programmed for continuous recording throughout the experimental session, covering the pre-exercise, during exercise with arm ergometer, and post-exercise periods.
Time frame: Just before, during 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 minutes of exercise, and after 10 minutes of exercise.
Nitric oxide production markers (micromol)
Before and after the sessions, a venous blood sample (10 mL) will be collected in tubes containing Ethylenediaminetetraacetic Acid (EDTA). Plasma will be immediately obtained after refrigerated centrifugation and used for the determination of thiobarbituric acid reactive substances (TBARS), nitrite, and nitrate (Griess test, Sigma Aldrich), as well as for biochemical analyses of lipids (cholesterol, triglycerides, High-Density Lipoprotein (HDL) cholesterol, and Low-Density Lipoprotein (LDL) cholesterol calculation) and glucose levels. Glycated hemoglobin will be determined in whole blood by high-performance liquid chromatography. Cultured human umbilical vein endothelial cells (HUVEC) will be incubated with 0.2% plasma obtained from all individuals for different time intervals. Indicators of nitric oxide production will be determined in the cells (cGMP concentration and endothelial nitric oxide synthase \[eNOS\] expression) and in the culture medium (nitrite/nitrate concentration).
Time frame: Before and after 5 minutes of exercise.
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