Clinical Trial: Effects of Aerobic Exercise in Patients With Pre-diabetes

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: The Effect of Controlled Aerobic Exercise on Endothelial Dysfunction and Vascular Reactivity in Patients With Pre-diabetes: A Crossover Pilot Study

Brief Summary: It is well known that diabetes and excessive or high blood sugars causes blood vessel and blood cell damage. It is also possible, then, that people with pre-diabetes may also start to have blood vessel and blood cell damage as the blood sugars rise from the normal range into the diabetic range. In addition to looking at potential damage, the question is whether or not this damage improves with exercise. This study aims to look at blood vessel and blood cells in three different ways by 1) looking at how the blood vessel responds to "sheer force" (a blood pressure cuff pumped up and then released after a few minutes). This is done by ultrasound. 2) By looking at blood tests such as blood sugar, cholesterol, and inflammation and 3) By looking at certain blood cells in the lab, how long they live and the number of cells left after a certain number of days, and again, if this improves with exercise.

Detailed Summary:

  • To refine a non-invasive test for endothelial dysfunction. The investigators will examine the flow response to sheer-stress induced by the relief of pressure exerted with a blood pressure cuff on the brachial artery, measuring flow responses with Doppler. This is a measure of local nitric oxide production from endothelial cells which is known to be impaired in diabetics, normal in non-diabetics, but unknown in prediabetics.
  • To measure in the same individuals indicators of glucose metabolism abnormalities including fasting blood glucose, HbA1C, insulin sensitivity by homeostasis model assessment-estimated insulin resistance (HOMA-IR) and insulin levels.
  • To measure Endothelial Progenitor Cell (EPC) count, viability, gene expression of key genes such as endothelial nitric oxide synthase (eNOS), von-Willebrand's Factor (vWF) and adhesion molecules such platelet-endothelial cell adhesion molecule-1 (PECAM-1 or CD31), cadherin such as Vascular-Endothelial cadherin (VE-cadherin)or CD (cell surface marker)-144, growth factors such as vascular-endothelial growth factor (VEGF)and Insulin like growth factor (IGF-1)in the EPCs from pre-diabetes subjects pre and post exercise.
  • Correlate the glucose metabolism abnormalities with potential causative factors of endothelial dysfunction by studying EPC functions such as migration and tube formation and susceptibility to apoptosis in moderate hyperglycemia. Apoptosis assay will be done by Flow Cytometry analysis using Annexin V- Propidium-iodide dye.
  • Subjects will be randomized to the intervention (structured exercise) or continuation of their usual life style (non-exercise, sedentary)group.

In both arms of the study, subjects will be encouraged to adhere to the st
Sponsor: Baystate Medical Center

Current Primary Outcome: Measures of Endothelial Function by studying number, function and gene expression of endothelial progenitor cells (identified as CD34+ cells) [ Time Frame: 16 weeks per patient ]

A. Number of viable CD34 +ve cells at Day-0 and viability assay. B. Colony Formation count assay at Day-5, pre and post exercise. C. We will test CD34+ cell migration, adhesion and tube formation properties. D. Gene expression in CD34+ cells of critical endothelial function and inflammatory genes will be measured: eNOS, vWF and PECAM1, VE-cadherin, VEGF-A, Superoxide dismutase (SOD)-1, 2 and 3, Catalase, Interleukin (IL)-6, Tumor Necrosis Factor (TNF alpha), P53, P21, PUMA, Bcl2 [Apoptosis genes] will also be noted


Original Primary Outcome: Same as current

Current Secondary Outcome: Measures of Vacular Reactivity [ Time Frame: 16 weeks ]

A) Measure Brachial reactivity through shear-stress using flow mediated dilatation (FMD) B). Measure Arterial Stiffness measure pre and post exercise. C) Measure Carotid Intima Media Thickness will be measured at each time point


Original Secondary Outcome: Same as current

Information By: Baystate Medical Center

Dates:
Date Received: May 9, 2013
Date Started: March 2010
Date Completion:
Last Updated: July 16, 2014
Last Verified: July 2014