The Effects of Two Days of Bedrest on Insulin Resistance in Type 2 Diabetics
Condition: Type 2 Diabetes; Insulin Resistance
MeSH terms: Diabetes Mellitus, Type 2; Insulin Resistance
Study type: Interventional

Summary: 
      The hypothesis of this study is that bed rest in diabetic patients will result in a
      deterioration of metabolic control (primarily glucose).

      Specific aims:

        1. To determine the change in metabolic control in type 2 diabetic individuals when three
           days of bed rest is compared to three days of activity;

        2. To determine the rate of progression of the deterioration in metabolic control and the
           magnitude of the decrease;

        3. To assess whether the anticipated deterioration of metabolic control has effects on
           several parameters of glucose metabolism, including hyperglycemia and hypoglycemia;

        4. To determine the effects of bed rest on surrogate markers of atherosclerosis, such as
           plasminogen activator inhibitor 1 (PAI1), C-reactive protein (CRP), and homocysteine.

        5. To compare the effects of 48 hours of bed rest on orthostatic responses in type 2
           diabetic patients, and healthy non-diabetics.

        6. To make recommendations to the diabetic community to prevent metabolic deterioration
           during a 3 day hospitalization.
    

Detailed description: 
      The goal for all diabetic patients is to maintain their metabolic control as close to normal
      as possible to prevent the short and long term complications of diabetes. Surgery of any type
      presents a unique challenge to the diabetic patient because two factors tend to worsen their
      metabolic control 1) the stress of the actual surgery and 2) the bed rest that follows the
      surgery. Data has clearly shown that surgery increase counter regulatory hormones
      (epinephrine, glucagon, growth hormone and cortisol). What has not been studied is the effect
      of bed rest per se on metabolic control. This is surprising because there are many studies in
      normal healthy people demonstrating that simple bed rest increases insulin resistance and
      worsens metabolic control.

      The proposed study will define the metabolic effects of simple, three-day bed rest on
      metabolic control in healthy type 2 diabetic volunteers while evaluating the orthostatic
      response after bed rest. All studies will be done in the inpatient, General Clinical Research
      Center (GCRC). All volunteers will stop their oral antidiabetic medication before they enter
      the GCRC. They will be placed on intravenous insulin to prevent severe metabolic
      deterioration and hyperglycemia. The amount of insulin we have to give them to maintain
      metabolic control will be one measure of the effects of bed rest on metabolic control.

      Experimental Design and Methods.

      A crossover study in twenty healthy normal and twenty healthy type 2 diabetic subjects will
      be utilized. Each subject will be admitted the the GCRC the night prior to beginning the
      study in order to insure metabolic stability at the start of the protocol. Each subject will
      stay in the GCRC three full days (three nights) from the time of admission. Each subject will
      be admitted on two separate occasions, separated by at least a two week interval. A diagram
      of the protocol is given below:

      The primary difference between the two admissions will be the amount of physical activity
      allowed each subject. On the normal physical activity GCRC admission, the subject will be
      encouraged to stay our of bed until his/her usual bedtime. All procedures and meals will take
      place in the GCRC but in between times the subject will be encouraged to walk around the
      hospital and to carry out normal activities of daily living. On the bed rest GCRC admission,
      the subjects will be encouraged to stay in bed as much as possible and to use a bedside
      commode. A tilt test was performed on the morning of the first day of each hospitalization
      and again 48 hours later. The same testing will be done as in the normal activity admission.

      All medications that the volunteer usually takes at home will be continued in the hospital.

      The volunteer will be in the GCRC for three days: Day 1, Day 2, and Day 3. The following
      tests will be done on the three days:

      Day 1 - Blood will drawn for fasting lipids, glucose, insulin, and C-peptide as well as
      surrogate markers of atherosclerosis including PAI-1, IL-6, homocysteine, fibrinogen, and
      CRP. In addition, a tilt table test will be done to assess autonomic response to activity or
      bedrest.

      Day 2 - Blood will drawn for fasting lipids, glucose, insulin, and C-peptide as well as
      surrogate markers of atherosclerosis including PAI-1, IL-6, homocysteine, fibrinogen, and
      CRP.

      Day 3 - Blood will drawn for fasting lipids, glucose, insulin, and C-peptide as well as
      surrogate markers of atherosclerosis including PAI-1, IL-6, homocysteine, fibrinogen, and
      CRP. In addition, a tilt table test will be done to assess autonomic response to activity or
      bed rest.
    

Intervention name(s): Study 2 (48 hours of complete bed rest)
Intervention type(s): Other
Intervention description(s): Effects of 48 hours of bed rest on insulin resistance in type 2 diabetic subjects.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: type 2 diabetes; bed rest; insulin resistance; insulin; glucose; orthostatic response