HIIT and MICT on Nitric Oxide-mediated Erythrocyte Rheology

Study Overview
=================
Brief Summary
-----------------
Erythrocyte rheological properties affect blood viscoelasticity and consequently regulate vascular resistance to flow shear force, whereas rheological impairments of erythrocytes may result in circulatory disorders. The aim of this study was to establish an effective exercise strategy for improving individual aerobic capacity and for simultaneously ameliorating the risk of hemorheological dysfunction evoked by a graded exercise test (GXT) and the hypotheses is exercise intervention will improved hemorheological functions by enhancing deformability of erythrocytes via NO-mediated mechanism. This study included 60 healthy sedentary mens (age 20 30) from Chang Gung university than were randomized into the HIIT [3-min intervals at 40% and 80% V̇O2 reserve (V̇O2R),n=10] and MICT(sustained 60% V̇O2R,n=10)on a bicycle ergometer for 30min·d-1, 5 d·wk-1 for 6 wk.

Detailed Description
-----------------
Recently, the role of erythrocyte has been more emphasized, which also related with endothelial cell. For coronary artery patients, the endothelial nitric oxide synthase activity in red blood cell (RBC-eNOS activity) is lower than age-matched health people, and it is related with dysfunction of endothelial cell. In cardiovascular diseases. the erythrocyte arginase-1 is active and seize L-arginine with eNOS. When the Arg-1 stimulated by reactive oxygen species (ROS), the nitric oxide (NO) bioactivity decrease and produce more ROS, meanwhile, ROS can go around to stimulate Arg-1. When the RBC-NO production is lowering, it will increase the adhesion activity to endothelial cell due to erythrocyte can be quite close to blood vessel well then release Nitric Oxide, induce the dysfunction and oxidative pressure of endothelial cell. The NO can also regulate the deformability of erythrocytes, and extremely affect oxygen supply to tissue once the deformability and aggregation of erythrocyte become abnormal. Besides NO, the deformability will be affected if erythrocyte is continuously exposed to the endogenous or exogenous ROS, which also increase adhesion to endothelial cell with the exposure of phosphatidylserine. Exercise can regulate the mechanism of NO release from erythrocyte, affecting the rheology of erythrocyte, and improve the anti-oxidation ability. Therefore, as mentioned above which make erythrocyte, as many aspects, become an important role on atherosclerosis disease treatment.

Official Title
-----------------
Effects of High Intensity Interval Training and Moderate Intensity Continuous Training on Nitric Oxide-mediated Erythrocyte Rheology

Conditions
-----------------
Exercise, Interval Training

Intervention / Treatment
-----------------
* Behavioral: High intensity-interval training (HIIT)
* Behavioral: Moderate intensity-continuous (MICT)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Having a sedentary lifestyle (without regular exercise, exercise frequency ≤ once weekly, duration < 20 min). Exclusion Criteria: Exposed to high altitudes (> 3000 m) for at least 1 year. Smoker Taking medications or vitamins Having any cardiopulmonary/hematological risk.

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 30 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High intensity-interval training (HIIT)<br>Subjects performed HIIT (3-min intervals at 40% and 80%VO2peak) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks. | Behavioral: High intensity-interval training (HIIT)<br>* Subjects performed HIIT (3-min intervals at 40% and 80%VO2peak) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks. Without any exercise training<br>|
| Experimental: Moderate intensity-continuous (MICT)<br>Subjects performed MICT (sustained 60%VO 2max) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks. | Behavioral: Moderate intensity-continuous (MICT)<br>* Subjects performed MICT (sustained 60%VO 2max) on a bicycle ergometer for 30 min/day, 5 days/week for 6 weeks.<br>|
| No Intervention: Control group<br>Without any exercise training | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intracellular NO production response to exercise training. | Added different inhibitors or agonists to investigate the effects of exercise training on NO production mediated by eNOS-NO pathway. | 8 weeks | 
| Intracellular ROS production response to exercise training. | Added different inhibitors or agonists to investigate the effects of exercise training on ROS production mediated by eNOS-NO pathway. | 8 weeks | 
| The levels of eNOS, p-eNOS and Band-3 response to exercise training. | Detect the following protein levels: eNOS, p-eNOS and Band-3, by the western blots. | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Determination of erythrocyte biological markers by Flow Cytometry | Using the Flow Cytometry to detect the following markers: CD242, CD239, NADPH oxidase 2 (Nox2) and Arginase 1 (Arg1). | 8 weeks | 
| Erythrocyte deformability | Isolated erythrocyte first, then assess erythrocyte deformability (elongation index ) by using laser assisted optical rotational red cell analyzer (LoRRca). | 8 weeks | 
| Cardiopulmonary fitness | To assess cardiopulmonary fitness, cardiopulmonary exercise test (CPET) on a cycle ergometer was performed 4 days before and after the intervention. All subjects underwent exercise with a mask to measured oxygen consumption (VO2) breath by breath using a computer-based system. | 8 weeks | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Erythrocyte, eNOS, High intensity interval training, deformability