Clinical trial NCT02448030: Effects of Functional Electrical Stimulation on Metaboreflex Activation in Healthy Individuals
Official title: Effects of Functional Electrical Stimulation Compared to Isometric Exercise on Metaboreflex Activation in Healthy Individuals: Randomized Crossover Clinical Trial
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: EARLY_PHASE1
Conditions: Reduction of Blood Flow
Keywords: Metaboreflex
Variation of blood flow
Functional electrical stimulation
Isometric exercise.
Lead sponsor: Hospital de Clinicas de Porto Alegre
Sponsor class: OTHER
First posted: 2015-05-19
Enrollment: 20
Sex: ALL
Minimum age (years): 35
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: Cardiovascular exercise adjustments are required during in order to redistribute blood flow from non-exercising vascular areas to active muscles. This hemodynamic adjustments, which are partially mediated by mechanosensitive and metabosensitive reflexes, ultimately increase oxygen and nutrient delivery to exercising muscle tissues (Mitchell, 1990). Static handgrip exercise has been shown to induce alterations in the arterial baroreflex function (Kim, 2005) and activation of muscle metaboreflex that increases arterial blood pressure and peripheral vasoconstriction, respectively. Functional electrical stimulation (FES) treatment used in physical therapy in patients who are unable to tolerate conventional exercise showed to be a good alternative for muscle strengthening (Sbruzzi, 2010) and to improve metabolic abnormalities (Karavidas, 2006). However, the effect of FES on metaboreflex activation in healthy individuals has never been investigated. Therefore, this study aims to evaluate the metaboreflex activation induced by FES in upper and low limbs in healthy individuals, and also to compare their results with the effects caused by isometric exercise.

Detailed description: All participants will be invited to attend four separate days for completion of the study protocols. On the first day, the metaboreflex activation in upper limb will be randomly assigned to isometric exercise or FES intervention. On the second day, at least two days apart, random isometric exercise or FES intervention will be performed in the upper limb. On the third day, at least one week apart, all participants will be assigned to perform metaboreflex in a lower limb induced by isometric exercise or FES intervention. On the fourth day, at least two days apart, random isometric exercise or FES intervention will be performed in a lower limb. To evaluate the isometric exercise and FES intervention the post-exercise ischemia will be randomly performed to evaluate the accumulation of metabolites in response to activated limb (PECO +) and evaluation control without ischemia (PECO-). The experiments between PECO+ and PECO- will be separated by a 30 min interval. During isometric exercise and FES protocols the blood flow and peripheral vascular resistance will be assessed by venous occlusion plethysmography. Fatigue will be determined every minute by the 10-point Borg scale to assess rate of perceived exertion and by blood lactate. Blood lactate will be evaluated through capillary action at pre, immediately post exercise and at 5 minutes during the recovery period. Hemodynamic variables such as BP and HR will be recorded every minute during the protocols.

Eligibility criteria: Inclusion Criteria:

* Healthy individuals
* Both genders
* Aged 35-70 years
* Sedentary
* Not using continuous medications

Exclusion Criteria:

* Cardiovascular disease
* Neurological disease
* Malignant disease
* Peripheral vascular disorders (varicose veins or deep vein thrombosis)
* Peripheral sensitivity alterations
* Contraindication to performing physical exercise
* Refusal to sign the consent form

Primary outcomes:
measure: Forearm and calf blood flow change
timeFrame: 5 minutes of exercise ( when PECO-) or to fatigue (when PECO +)
Secondary outcomes:
measure: Maximum muscle strength
timeFrame: The maximum peak strength will be measured 3 times with 1 minute interval between each measurement before a session of isometric exercise
measure: Peripheral vascular resistance
timeFrame: It is calculated using data obtained from blood flow and mean arterial pressure in the protocols at 3 minutes in both PECO+ and PECO-
Other outcomes:
Locations:
city: Porto Alegre
country: Brazil
facility: Hospital de Clinicas de Porto Alegre
state: RS
Study officials:
affiliation: Hospital de Clinicas de Porto Alegre
name: Beatriz Dr Schaan, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Federal University of Rio Grande do Sul
name: Aline Macedo, Graduate
role: STUDY_CHAIR
References:
citation: Mitchell JH. J.B. Wolffe memorial lecture. Neural control of the circulation during exercise. Med Sci Sports Exerc. 1990 Apr;22(2):141-54. No abstract available.
citation: Rowell LB, O'Leary DS. Reflex control of the circulation during exercise: chemoreflexes and mechanoreflexes. J Appl Physiol (1985). 1990 Aug;69(2):407-18. doi: 10.1152/jappl.1990.69.2.407.
citation: Kim JK, Sala-Mercado JA, Rodriguez J, Scislo TJ, O'Leary DS. Arterial baroreflex alters strength and mechanisms of muscle metaboreflex during dynamic exercise. Am J Physiol Heart Circ Physiol. 2005 Mar;288(3):H1374-80. doi: 10.1152/ajpheart.01040.2004. Epub 2004 Nov 11.
citation: Sbruzzi G, Ribeiro RA, Schaan BD, Signori LU, Silva AM, Irigoyen MC, Plentz RD. Functional electrical stimulation in the treatment of patients with chronic heart failure: a meta-analysis of randomized controlled trials. Eur J Cardiovasc Prev Rehabil. 2010 Jun;17(3):254-60. doi: 10.1097/HJR.0b013e328339b5a2.
citation: Karavidas AI, Raisakis KG, Parissis JT, Tsekoura DK, Adamopoulos S, Korres DA, Farmakis D, Zacharoulis A, Fotiadis I, Matsakas E, Zacharoulis A. Functional electrical stimulation improves endothelial function and reduces peripheral immune responses in patients with chronic heart failure. Eur J Cardiovasc Prev Rehabil. 2006 Aug;13(4):592-7. doi: 10.1097/01.hjr.0000219111.02544.ff.