Myotonic Dystrophy Type 1 Aerobic Exercise Study
Condition: Myotonic Dystrophy 1; Muscular Dystrophies
MeSH terms: Muscular Dystrophies; Myotonic Dystrophy
Study type: Interventional

Summary: 
      Myotonic dystrophy type 1 (DM1) is a genetic disease that primarily targets skeletal muscle
      resulting in severe weakness and muscle loss. As a result, individuals suffering from DM1
      become very inactive and lose mobility resulting in a lower quality of life. This study will
      investigate the effect of a 12-week moderate intensity exercise protocol on skeletal muscle
      function and cellular benefits in DM1 patients.
    

Detailed description: 
      The present study is a repeated measures design, with sampling of the cohorts on two separate
      occasions. Upon obtaining informed consent, participants will be assigned into one of two
      groups:

      Group 1: DM1 Exercise Group DM1 diagnosed, physically inactive males, n = 6 DM1 diagnosed,
      physically inactive females, n = 7

      Group 2: Healthy controls (no exercise) Healthy, physically inactive males n = 6 Healthy,
      physically inactive females n = 7

      Introduction - Day 1 (Visit 1); On the initial visit, the potential participant will come to
      McMaster Children's Hospital to meet with a study coordinator involved in the project. The
      coordinator will explain the study in detail, answer any questions, and review the consent
      form. Upon obtaining informed consent, eligible participants will complete a medical
      screening questionnaire to determine their readiness to perform exercise. Participant
      characteristics will then be measured. At this time, anthropometric measurements (i.e.,
      height, weight, waist circumference) and a dual energy x-ray absorptiometry (DXA) measurement
      will be performed. This must be done in order to verify that the participant meets the
      inclusion criteria of being normal weight (BMI 18.5 - 24.9 kg/m2) or overweight (BMI 25 -
      29.9 kg/m2). Following this screening, participants will undergo an ECG to measure any
      conductance blockage and perform a maximal cycling test to determine their aerobic capacity
      (V02max). Maximal aerobic testing will then be followed by another 12 lead ECG to detect any
      possible structural cardiac issues in our participants. Thereafter, participants will begin
      the following the study timeline, all of which will occur at the McMaster Children's
      Hospital, 2H Neurometabolic Clinic.

      Baseline testing - Day 3 (Visit 2); Participants will arrive the following day to undergo
      functional testing which will include 6-minute walk test, 5x sit to stand, timed up and go,
      grip strength and maximal voluntary knee extension using the Biodex dynamometer. Participants
      will then complete the SF-36.

      Follow up testing - Day 5 (Visit 3); Participants will arrive following an overnight fast
      (including no caffeine for 12 hours) and having abstained from any exercise for the prior 24
      hours. Participants will undergo a muscle biopsy from the vastus lateralis.

      DM1 participants only:

      Exercise training - Visit 4 - 39; Participants will begin the exercise protocol consisting of
      3 exercise sessions per week for a 12-week period. All exercise sessions will be done on a
      cycle ergometer (Lode, Groningen, Netherlands). Each exercise session will consist of 3
      minutes of warm up, 30 minutes at 65% V02max and will end with 2 minutes of cool down.
      Exercise progression over the 12 weeks will go as follows:

        -  Weeks 1 and 2: 3 min warm up, 65% VO2max for 30 min, 2 min cool down

        -  Weeks 3 and 4: increase to 35 min (+ warm up/cool down)

        -  Weeks 5 and 6: drop to 30 min and increase to 70% VO2max

        -  Weeks 7 and 8: increase to 35 min (+ warm up/cool down)

        -  Weeks 9 and 10: drop to 30 min and increase to 75%VO2 max

        -  Weeks 11 and 12: increase to 35 min (+ warm up/cool down)

      Endpoint testing - Visit 40; At this time, anthropometric re-measurements (i.e., height,
      weight, waist circumference) and a dual energy x-ray absorptiometry (DXA) measurement will be
      performed. Thereafter, participants will undergo an ECG to measure any conductance blockage
      and perform a maximal cycling test to determine their aerobic capacity (V02peak). Maximal
      aerobic testing will then be followed by another 12 lead ECG to detect any possible
      structural cardiac issues in our participants.

      Endpoint testing - Visit 41; Participants will arrive the following day to undergo functional
      testing which will include 6-minute walk test, timed up and go, grip strength and maximal
      voluntary knee extension using the Biodex dynamometer. Participants will then complete the
      SF-36.

      Endpoint testing - Visit 42; Participants will arrive following an overnight fast (including
      no caffeine for 12 hours) and having abstained from any exercise for the prior 24 hours.
      Participants will undergo a muscle biopsy from the vastus lateralis.
    

Intervention name(s): Exercise training
Intervention type(s): Other
Intervention description(s): All participants with DM1 will undergo a 12-week aerobic exercise training intervention on a cycle ergometer
Intervention model: Single Group Assignment
Intervention model description: Participants are undergoing 12-weeks of aerobic exercise training
Masking: None (Open Label)
Primary purpose: Supportive Care
Keywords: aerobic exercise