Comparison of A New Technique of Measure of the Insulin Resistance By Scintigraphy With the Reference Technique
Condition: Diabetes Mellitus; Insulin Resistance; Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases
MeSH terms: Insulin Resistance; Metabolic Diseases; Glucose Metabolism Disorders; Endocrine System Diseases
Study type: Interventional
Phase: Phase 2

Summary: 
      Insulin resistance is closely associated with apparition of type 2 diabetes mellitus; it is
      an independent risk factor and predicts future cardiovascular events.

      Hyperinsulinemic euglycemic clamp is a validated method to assessment of insulin resistance
      and It is also the gold standard technique. However, the complexity and length of this
      technique render it unsuitable for routine clinical use.

      In this study, the investigators use a new technique to provide precise, objective, fast and
      automated quantification of insulin resistance with camera SPECT.

      They compare the results with those of the measurement of hyperinsulinemic euglycemic clamp
      in population with or without insulin resistance.

      The proposed study is to validate this new non-invasive imaging technique for evaluation of
      insulin resistance in patients with or without insulin resistance with a comparison with
      hyperinsulinemic euglycemic clamp.
    

Detailed description: 
      Currently, type II diabetes mellitus, has reached epidemic levels in the world. Moreover, the
      prediction for the year 2030 is even more alarming. Insulin resistance, characterized by a
      depressed cellular sensitivity to insulin in insulin-sensitive organs, is a central feature
      of the metabolic syndrome and a risk factor for type 2 diabetes. Its appearance may precede
      the diagnosis of true diabetes several years. Insulin resistance results in decreased
      membrane translocation of GLUT-4, whole the molecular mechanism remains unclear. Currently,
      there is no simple tool to measure insulin resistance. The gold standard technique remains
      the hyperinsulinemic euglycemic clamp. However, the complexity and length of this technique
      render it unsuitable for routine clinical use. Many methods or index have been proposed to
      assess insulin resistance in human, but none have shown enough relevance to be used in
      clinical use. Moreover, all these clinical measurements focus on whole-body glucose uptake,
      however an accurate and convenient procedure for insulin resistance measurement by organ
      would be interesting. Indeed there are increasingly evidences to insulin resistance as a
      primary etiologic factor in the development of nonischemic heart failure (HF), another
      growing public health problem.

      Nuclear imaging provides interesting methods to measure insulin resistance using Positron
      Emission Tomographic (PET) tracer. Two glucose analogs [18F]2-fluoro-2-deoxy-D-glucose (FDG)
      and [11Cl-30methyl-n-glucose (3-OMG) have been used to evaluate noninvasively the cellular
      uptake of glucose using PET techniques for several organs like heart, skeletal muscle
      blood-brain barrier, and liver. [18F] 2-fluoro-2-deoxy-D-glucose (FDG), the most commonly
      used to study glucose metabolism in humans, allows the estimation of glucose transport and
      its phosphorylation. A number of kinetic modeling approaches have been used for the
      quantitation of glucose utilization rates using FDG. FDG is transported and phosphorylated as
      native glucose, but calculation of glucose uptake and metabolism requires the use of
      correction factors for each process merged into a lumped constant. The major limitation of
      these approaches is that quantification of glucose metabolism requires the knowledge of the
      lumped constant, a factor, which relates the kinetic behavior of FDG to naturally occurring
      glucose in terms of the relative affinity of each molecule for the trans-sarcolemmal
      transporter and for hexokinase. Unfortunately, the value of the lumped constant in humans
      under different physiological and pathophysiological conditions varies, and metabolic imaging
      with PET need standardization of metabolic conditions by hyperinsulinaemic euglycaemic clamp.
      3-OMG appears as an ideal glucose analog to probe transmembrane transport. However, due to
      the short half-life of the 11C (t1/2 = 20 min), this analog can be used only in clinical
      institutions in close proximity of a cyclotron and which have access to PET devices.

      According to these knowledge, the investigators have developed an original compound, [123I]
      6-deoxy-6-iodo-D-glucose (6DIG), as a tracer of glucose transport equivalent to 3-OMG, the
      reference tracer. 6-DIG has previously been exploited to measure IR in vivo and the
      investigators transfer to human this measurement technique, perfectly validated in animal.
      Previous, they have reported the first use a potential single-photon emission computed
      tomography (SPECT) tracer to study basal and insulin-stimulated glucose transport
      non-invasively. In a phase I of development, they use a new nuclear probe using an iodinated
      tracer of glucose transport for clinical application and specific imaging processing to
      assess cardiac insulinoresistance in healthy or diabetic subjects. The results in human
      subjects show that this technique rapidly provides insulinoresistance index (ratio
      scintigraphy measurement of glucose transport in heart before and after infusion of insulin)
      in a simple procedure, opening up new opportunities for screening for pre-diabetic patients.
    

Intervention name(s): 6-DIG; clamp
Intervention type(s): Drug; Procedure
Intervention description(s): injection of 6-DIG; hyperinsulinemic euglycemic clamp
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: insulin resistance; Scintigraphy; Hyperinsulinemic euglycemic clamp