Preventing Diabetic Osteoporosis With Exercise
Condition: Diabetes Mellitus, Type 2
MeSH terms: Osteoporosis; Diabetes Mellitus, Type 2
Study type: Interventional

Summary: 
      The two specific aims of the study were to determine whether:

        1. Greater mechanical loading of downhill exercise will increase the osteogenic index
           (ratio between CICP, the marker of bone formation (c-terminal propeptide of type I
           collagen, and CTX, the marker of bone resorption (c terminal telopeptide of type I
           collagen)) to a greater extent than uphill exercise that provides lower ground-reaction
           force;

        2. Exercise after the meals will induce greater osteogenic response than exercise pefore
           the meals as it is known that meal eating during daytime inhibits bvone resorption
           markers.
    

Detailed description: 
      The study addresses the problem that postmenopausal women with type 2 diabetes have a higher
      incidence of bone breaks despite their often normal bone mineral density (BMD).

      The investigators pursued two hypotheses, that:

        1. 40-minute bout of downhill exercise will increase the CICP/CTX osteogenic index to a
           greater extent than the same amount of uphill exercise; and

        2. Performing exercise one hour after the meals will be more osteogenic than exercise
           before the meals.

      Subjects were 15 postmenopausal women with type 2 diabetes, age 57.7 years, BMI 27.2 kg/m2
      who were randomly assigned to two out of 5 trials:

      Uphill exercise before the meals (UBM), Uphill exercise after the meals (UAM), Downhill
      exercise before the meals (DBM), Downhill exercise after the meals (DAM), and Sedentary,
      no-exercise, trial (SED). All subjects signed an informed consent approved by the University
      of Michigan Medical School Institutional Review Board. Subjects had their BMD measured with
      DXA at the outset.

      Weight-maintenance meals contained 50% carbohydrate, 15% protein, and 25% fat and were
      provided at 10 h and 17 h. Exercise (40 minutes at 50% of maximal effort) on either uphill
      (+6o slope) or downhill treadmill (-6o slope) was performed either before the two meals, at 9
      h and 16 h, respectively, or after the meals. at 11 h and 18 h, respectively.

      Blood was drawn through an intravenous catheter from ante-cubital vein at hourly intervals
      between 8 and 20 h with two additional blood draws at 0 h and 6 h the next morning. Blood was
      treated with protease inhibitors, and plasma, frozen at -80o C, was used to measure bone
      markers, CICP, CTX, osteocalcin , and bone-specific alkaline phosphatase using Millipore
      chemoluminescen reagents, glucose by glucose oxidase, and hormones insulin, cortisol,
      parathyroid hormone (PTH) , and growth hormone (GH) by radio-immunoassays..

      Mixed-model ANOVA was used for analysis of outcome measures where the trial procedures served
      as fixed variable and individual subjects as intercept variables.
    

Intervention name(s): Behavior intervention of uphill exercise; Dietary intervention of exercise before the meal; Dietary intervention of uphill exercise; Dietary intervention of exercise after the meal; Behavior intervention of downhill exercise; Dietary intervention of exercise before the meal; Behavioral intervention of downhill exercise; Dietary intervention of exercise after the meal; Behavioral intervention of sedentary no-exercise trial; Dietary intervention of eating two meals
Intervention type(s): Combination Product; Combination Product; Combination Product; Combination Product; Combination Product; Combination Product; Combination Product; Combination Product; Combination Product; Combination Product
Intervention description(s): 40 minutes of uphill exercise; 40 minutes of uphill exercise completed 1 h before the meal; 40 minutes of uphill exercise; 40 minutes of uphill exercise started 1 hour after gthe meal; 40 minutes of downhill exercise; 40 minutes of downhill exercise completed 1 hour before the meal; 40 minutes of downhill exercise; 40 minutes of downhill exercise started 1 hour after the meal; Sedentary no-exercise trial; Meals eaten at 10 and 17 h during a sedentary trial
Allocation: Randomized
Intervention model: Factorial Assignment
Intervention model description: Study consisted of 5 experimental trials (or arms), of which 4 were compared to a sedentary (or control) arm. The five trials were: Uphill exercise before the meals (UBM), Uphill exercise after the meals (UAM), Downhill exercise before the meals (DBM), and Downhill exercise after the meals (DAM), and the Sedentary (Sed) or control trial.
Masking: None (Open Label)
Primary purpose: Basic Science