Effect of Weight-Bearing Exercise on People With Diabetes and Neuropathic Feet
Condition: Diabetes Mellitus; Peripheral Neuropathy
MeSH terms: Peripheral Nervous System Diseases; Diabetes Mellitus
Study type: Interventional

Summary: 
      The purpose of this study is to determine if people with Diabetes Mellitus and peripheral
      neuropathy can increase their activity (i.e. walking or stationary biking) and leg strength
      without having an increase in foot problems compared to a group of people with diabetes and
      peripheral neuropathy that do no exercise.

      Our hypothesis is that the weight-bearing exercise group will achieve greater increases in
      weight-bearing activity (i.e., increased steps/day and cumulative load) and leg strength
      compared to the non-weight bearing exercise group and the non-exercising control group; and
      there will be no clinically meaningful difference in incidence or indicators of foot lesions
      between groups.
    

Detailed description: 
      People with diabetes and peripheral neuropathy (DM+PN) have substantial lower extremity
      impairments, functional limitations and disability. In addition to muscle weakness and poor
      balance, they also are at high risk for foot ulcerations, especially if they have a history
      of ulceration. Although there is a large and growing body of knowledge about the effect of
      exercise on people with DM, there is little evidence about the effect of exercise in people
      with DM+PN. Exercise is an important treatment component to help control the complications of
      DM. The American Diabetes Association (ADA), and the American College of Sports Medicine
      (ACSM)4 recommend that adults with DM participate in at least 30 minutes a day of
      moderate-intensity physical activity that is consistent with a brisk walk. The ADA and ACSM,
      however, discourage weight-bearing exercise for people with DM+PN due to risk of
      exercise-induced foot injury. No data support this guideline to restrict those with DM+PN
      from weight-bearing activity, and in fact, some evidence suggests that those with DM+PN who
      are most active are least likely to develop skin breakdown. The Primary Goal of this proposal
      is to conduct a pilot randomized prospective controlled clinical trial to determine if people
      with DM+PN can benefit from a progressive weight-bearing exercise program to improve
      impairments, functional limitations, disability, and pathophysiology without an increase in
      skin breakdown or foot lesions. The benefits of a weight bearing program will be compared to
      the benefits of a non weight bearing exercise program and to a non-exercising control group.
      The results of this study also will help to determine if neuropathic skin and muscle can
      adapt to increasing physical stress levels without injury which could have important
      implications for weight-bearing and exercise guidelines for people with DM+PN.

      A. SPECIFIC AIMS

      Aim 1. Determine the effect of a weight-bearing exercise program compared to a non-weight
      bearing exercise program and to a non-exercising control group on indicators of impairments,
      functional limitations, disability, and pathophysiology in patients with DM+PN.

        1. Measures of Impairment: Ankle joint range of motion, ankle plantar flexor and
           dorsiflexor muscle strength (peak torque), muscle volume (magnetic resonance imaging),
           and standing balance.

           H1: Both exercise groups will show an improvement in ankle joint range of motion and
           ankle plantar flexor / dorsiflexor muscle strength / volume compared to the
           non-exercising control group, but only the weight-bearing exercise group will show an
           improvement in standing balance because of exposure to challenging weight-bearing
           activities.

        2. Measures of Functional Limitations: Physical Performance Test, Foot & Ankle Ability
           Measure.

           H2: Both exercise groups will show improvement in the Physical Performance Test and Foot
           & Ankle Ability Measure compared to the non-exercising control group, and the
           weight-bearing exercise group will show greater improvements than the non-weight bearing
           exercise group because of improved balance and exposure to challenging weight-bearing
           activities.

        3. Measures of Disability / Participation: Diabetes Symptom Checklist, Beck Depression
           Inventory.

           H3: Both exercise groups will show improved measures of disability compared to the
           non-exercising control group, and the weight-bearing exercise group will show greater
           improvements than the non-weight bearing exercise group because of improved ability to
           participate in community activities which require weight-bearing and walking ability.

        4. Measures of Pathophysiology: HbA1c, serum lipids, DXA (body composition), and body mass
           index.

      H4: Both exercise groups will show modest but statistically significant improvements compared
      to the non-exercising control group in the above measures of pathophysiology.

      Aim 2: Determine the effect of weight-bearing exercise program and non-weight bearing
      exercise program compared to a control group on 1) daily step count (steps/day), 2) an
      estimate of cumulative load (step count * plantar pressure integral), 3) unilateral increase
      in surface foot temperature, and 4) incidence of foot lesions (digital photograph).

      H5: The weight-bearing exercise group will achieve greater increases in weight-bearing
      activity (i.e., increased steps/day and cumulative load) compared to the non-weight bearing
      exercise group and the non-exercising control group; and there will be no clinically
      meaningful difference in incidence or indicators of foot lesions between groups.
    

Intervention name(s): weightbearing exercise; nonweightbearing exercise; nonexercising control
Intervention type(s): Behavioral; Behavioral; Behavioral
Intervention description(s): All subjects in the exercise group will participate, as able, in 3 supervised 1 hour exercise sessions per week for the first month and 2 supervised and 1 unsupervised exercise session per week for the remaining 2 months. Subjects in each exercise group will be seen on alternating times to avoid cross contamination of treatment intervention. Walking intensity for all subjects will be applied with the intent to exceed their routine physical stress level, and therefore incur positive adaptations to physical stress, but not exceed their threshold for injury.; All subjects in the 2 exercise groups will participate, as able, in 3 supervised 1 hour exercise sessions per week for the first month and 2 supervised and 1 unsupervised exercise session per week for the remaining 2 months. Subjects in each exercise group will be seen on alternating times to avoid cross contamination of treatment intervention. Biking intensity for all subjects will be applied with the intent to exceed their routine physical stress level, and therefore incur positive adaptations to physical stress, but not exceed their threshold for injury.; All subjects will be instructed, verbally and with written documents, regarding appropriate foot and skin care twice per month.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: diabetes mellitus; peripheral neuropathy; exercise