Aerobic Trainings on Stroke Patients
Condition: Stroke, Cardiovascular
MeSH terms: Stroke; Myocardial Infarction
Study type: Interventional

Summary: 
      Effects of different exercise strategies on stroke patients remain unclear. Randomized
      controlled trial with concealed allocation has been performed from August 1, 2016 to June 30,
      2018. We traced back 23 stroke patients, recruited during the above period, aged about 55
      years with stroke duration > 24 months . Intervention: 13 of them underwent 36 times of
      moderate-intensity continuous training (MICT) at 60% of peak oxygen consumption (VO2peak) for
      30 mins, and 10 had high-intensity interval training (HIIT) at alternative 80% and 40%
      VO2peak with the same training times and duration. Outcome measures: VO2peak, cardiac output
      (CO), bilateral frontal cortex blood volume (∆[THb]), oxyhemoglobin (∆[O2Hb]) and
      deoxyhemoglobin (∆[HHb]), ventilation efficiency, serum brain-derived neurotrophic factor
      (BDNF) levels, cognitive and life quality questionnaire, percentage of neuroblastic cell
      bearing neurites (% neurites), and cell fluorescent staining were examined before and after
      interventions.
    

Detailed description: 
      Design The Institutional Review Board of a tertiary care hospital approved the study (IRB No.
      201600576A3). A randomized controlled trial was performed in stroke patients with different
      exercise regimens and was blind to the assessors. The study was conducted from August 2016 to
      June 2018. Participants were randomly allocated to the MICT or HIIT groups using a
      computer-generated, concealed allocation schedule. All included stroke patients received
      traditional rehabilitation programs, including balance, range of motion, or therapeutic
      exercise, and additional in-hospital supervised 30 min of MICT or HIIT for 36 times. Data
      were collected by a blinded assessor prior to randomization after completing the exercise
      trainings.

      Participants Stroke patients, diagnosed by the neurologist, were surveyed. The inclusion
      criteria were listed as follows: (I) ≥ 20 years old; (II) stroke events with stable clinical
      status ≥ 3 months; (III) mini-mental state examination (MMSE)> 24; (IV) no acute coronary
      syndrome. Those who had unstable angina, systolic blood pressure> 200 mmHg or diastolic blood
      pressure> 110 mm Hg, symptomatic orthostatic hypotension, severe aortic stenosis (peak
      systolic pressure gradient> 50 mmHg, or an aortic valve opening area< 0.75 cm2), inflammatory
      disease within recent 3 months, uncontrolled cardiac dysrhythmias, uncompensated HF, third
      degree atrioventricular block, pericarditis or myocarditis within recent 3 months, embolic
      disease within recent 3 months, ST segment displacement≥ 2 mm at rest, and uncontrolled
      diabetes (blood glucose≥ 300 mg/dL or ≥ 250 mg/dL with ketone bodies) were not candidates of
      the study.

      Stroke patients had absolute contraindications for cardiopulmonary exercise test (CPET) and
      aerobic activities, suggested by the American College of Sports Medicine (ACSM), were also
      excluded in the study. Afterwards, eligible participants were randomly assigned to the MICT
      and HIIT groups. Baseline demographic characteristics were also recorded. All subjects
      provided informed consent after the experimental procedures were explained.

      Cardiopulmonary exercise test (CPET) Participants underwent an incremental exercise test on a
      bicycle ergometer (Ergoselect 150P, ergoline GmbH, Bitz, Germany) and the examination was
      performed at a work-rate of 10 W/min with continuous monitoring heart rate, brachial blood
      pressure, and arterial oxygen saturation, until the stop conditions described previously.
      Oxygen consumption (VO2) was measured by a cardiopulmonary measurement device (MasterScreen
      CPX, CareFusion Corp., Hoechberg, Germany). The VO2peak, minute ventilation (VE), and carbon
      dioxide production (VCO2) were defined as the guideline for exercise testing suggested by the
      ACSM. VE and VCO2 responses, acquired from the initiation of exercise to the peak values,
      were used to calculate the VE-VCO2 slope using the least-square linear regression. The O2
      uptake efﬁciency slope (OUES), an estimation of the O2 consumption efficiency during
      exercise, was derived from the slope of a natural logarithm plot of VE vs. VO2.

      Cardiac hemodynamic measurements Noninvasive continuous cardiac output monitoring system
      (NICOM, Cheetah Medical, Wilmington, Delaware) was used to evaluate cardiac hemodynamic
      response to exercise, which analyzes the phase shift (ΔΦ) created by alternating electrical
      current across the chest of the subject as described in our previous study.

      Cerebral hemodynamic measurements Two pairs of near infra-red spectroscopy (NIRS) probes
      (Oxymon, Artinis, The Netherland) were attached to bilateral frontal areas of each included
      subject during CPET. The Beer-Lambert law was applied to measure light absorption across each
      pair of NIRS detectors reflecting changes of oxyhemoglobin ([O2Hb]) and deoxyhemoglobin
      ([HHb]) in the frontal cortex during exercise. Total Hb amount ([THb]) was calculated as the
      sum of [O2Hb] and [HHb], and was used as an index of change in blood volume in the frontal
      cortex. Differences of the tissue oxygenation (Δ[O2Hb] and Δ[HHb]) and regional blood flow
      (Δ[THb]) between involved and uninvolved frontal cortices (involved-uninvolved) were used to
      estimate effects of different exercise regimens on brain tissue oxygenation and regional
      blood flow.

      Health-related QoL QoL was measured by the Short Form-36 Health Survey questionnaire (SF-36),
      and mini-mental status examination (MMSE) was used to assess QoL and cognitive functions of
      the participants.

      Exercise training protocols The included subjects underwent 36 times of supervised
      hospital-based training (2-3 session/week) on a bicycle ergometer (Ergoselect 150P, Germany)
      as our previous protocol.15 The training comprised a warm-up at 30% of VO2peak for 3 min,
      followed by a MICT (60% of VO2peak) or HIIT (five 3-min intervals at 80% of VO2peak and each
      interval separated by 3-min exercise at 40% of VO2peak) for 30 min, and then a cool-down at
      30% of VO2peak for 3 min. The training was terminated when the subject had symptoms/signs
      suggested by the ACSM guideline.

      Serum preparation An amount of 20 ml fresh blood was collected from all our subjects before
      and after exercise training. Samples were centrifuged at 2500 rpm for 5 min at room
      temperature, and the upper serum was preserved for cell culture and measurement of serum BDNF
      levels.

      Measurement of serum BDNF BDNF levels were assessed before and after aerobic exercise
      trainings. Prepared serum of 100 µL was added in each well coated with the human BDNF capture
      antibody in a solid-phase sandwich, two-site enzyme linked immunoassay (ELISA) kit (BioVision
      Inc., Milpitas, CA). The BDNF level was then determined by the microplate reader (SpectraMax
      M3, Molecular Devices LLC, San Jose, CA).

      Cell culture and neurite growth assay Rat neuroblastic cells (PC-12 cell line) were grown in
      Dulbecco's modified Eagle's medium (DMEM) supplemented with 7.5% patient serum (before and
      after exercise training), 7.5% horse serum (HS), 100 units/ml penicillin, and 100 mg/L
      streptomycin.

      A total of 100000 cells were plated overnight on 35-mm dishes coated with poly- DL-lysine.
      After serum starvation in DMEM containing 2% HS for 12-18 h, cells were treated with 50 ng/ml
      NGF for the indicated time. Morphological changes were observed using the Leica TCS SP8
      confocal microscopy 7 days after cultured with patient sera before and after exercise
      training. Percentage of cells with neurites of at least one cell body diameter in length was
      determined in five independent fields of every plate.

      Fluorescent stains Cells (100000) were inoculated in each well of the eight-chamber slide
      (Millicell EZ slide, Millipore Corp., Billerica, MA) and were incubated at the pre- and
      post-MICT or HIIT sera for 12h. Vivid staining of Mitotracker (Invitrogen corp., Carlsbad,
      CA) was used to observe mitochondria in neuroblastic cells treated with sera from the above
      different status. The cells were stained with primary rabbit monoclonal anti-⍺-tubulin
      antibodies (Cell Signaling Technology Inc., Boston, MA). Fluorescein
      isothiocyanate-conjugated AffiniPure Goat anti-rabbit IgG (Jackson ImmunoResearch
      Laboratories, West Grove, PA) was used as the secondary antibody. Nuclei were counterstained
      with mounting medium (Vector Laboratories Inc., Burlingame, CA) containing
      40,6-diamidino-2-phenylindole. The stained cells were examined with a confocal microscopic
      examination (Leica TCS SP8, Leica Microsystems Inc., Buffalo Grove, IL).

      Statistical analysis Chi-square test was conducted to compare differences of non-parametric
      parameters between the two groups. Mann-Whitney U test was used to assess differences of age,
      stroke duration, body mass index (BMI), changes of exercise capacity, changes of brain
      oxygenation as well as regional blood volume, changes of BDNF levels, and changes of cell
      behaviors between the two groups. Differences of within group changes in numerical data was
      assessed by Wilcoxon matched-pair signed-rank test. Relationships between changes of measured
      clinical parameters after the exercise training and clinical information were analyzed by
      Pearson correlation. A p value < 0.05 was considered as statistical significance.
    

Intervention name(s): Aerobic exercise training
Intervention type(s): Behavioral
Intervention description(s): All recruited subjects underwent 36 times of moderate-intensity continuous training (MICT) at 60% of peak oxygen consumption (VO2peak) for 30 mins, and 10or had high-intensity interval training (HIIT) at alternative 80% and 40% VO2peak with the same training times and duration.
Intervention model: Single Group Assignment
Intervention model description: A randomized controlled trial was performed in stroke patients adequate for exercise trainings. Different exercise regimens were prescribed and was blind to the assessors. The study was conducted from August 2016 to June 2018. Participants were randomly allocated to the moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT) groups using a computer-generated, concealed allocation schedule. All included stroke patients received traditional rehabilitation programs, including balance, range of motion, or therapeutic exercise, and additional in-hospital supervised 30 min of MICT or HIIT for 36 times. Data were collected by a blinded assessor prior to randomization after completing the exercise trainings.
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Stroke; Oxygen consumption; BDNF; Dendrites