A Prospective Study of Endothelial Dysfunction and Diabetic Foot Ulcer Risk

January 20, 2009 updated by: US Department of Veterans Affairs

This project will identify risk factors for diabetic foot ulcer by studying the relationship between endothelial dysfunction and foot ulcer risk. A fundamental defect in type 1 and 2 diabetic subjects is impaired vasodilatory reserve which is reflected in the dysfunction of endothelium-dependent vasodilation. Findings thus far point to an important role of the microvasculature in the development of diabetic foot ulcer and amputation.

In this study a a well-characterized cohort of 750 diabetic veterans without foot ulcer will be followed over 3-years.

Study Overview

Status

Completed

Detailed Description

Prevention of foot ulcer should result in a reduction in the risk of lower limb amputation. We propose to identify risk factors for diabetic foot ulcer by studying the relationship between endothelial dysfunction and foot ulcer risk. It has been proposed that impaired vasoregulation in diabetic patients leads to the development and perpetuation of chronic foot ulceration via failure of the normal hyperemic response to injury. A fundamental defect that has been demonstrated in type 1 and 2 diabetic subjects is impaired vasodilatory reserve, which reflects dysfunction of endothelium-dependent vasodilation. Our findings thus far point to an important role of the microvasculature in the development of diabetic foot ulcer and amputation, with our demonstration of higher foot ulcer and lower-limb amputation risk in relation to lower dorsal foot transcutaneous oxygen level. The role of endothelial dysfunction in relation to diabetic foot ulcer risk has not previously been studied.

We will follow a well-characterized cohort of 750 diabetic veterans without foot ulcer over 3-year after obtaining baseline measures of endothelial function using iontophoretic application of acetylcholine to induce cutaneous endothelium-dependent vasodilation on the dorsal foot. Iontophoresis permits noninvasive delivery of ionic drugs cutaneously without damage to the skin or systemic effects. Change in microvascular flow will be measured using a laser Doppler imager (Moor LDI) over a 4x4 cm area divided into 18496 measurement sites. Endothelial function will be defined as the difference between readings before and after the iontophoretic application of a 1% acetylcholine solution at a current of 0.2 mA for 1 minute, with higher readings reflecting better endothelial function. These techniques are the accepted standard method for assessment of endothelium-dependent vasodilation in the cutaneous microvasculature. Additional measurements will be obtained on other ulcer risk factors to assess whether endothelial dysfunction independently influences foot ulcer risk, or whether it is merely a marker for different pathophysiologic conditions responsible for higher risk (eg., sensory neuropathy). Possible confounding factors considered will include sensory and autonomic neuropathy; dorsal foot transcutaneous oximetry; macrovascular function assessed with Doppler blood pressures; diabetes characteristics; in-shoe plantar pressure (F-scan), medication use, and foot deformity.

Study Type

Observational

Enrollment

750

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Washington
      • Seattle, Washington, United States
        • VAMC, Seattle, WA

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Diabetic patients with foot ulcers

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • John Fryer, Ph.D. Asst. Director, Program Analysis and Review Section (PARS), Rehabilitation Research & Development Service
  • Wijegupta Ellepola, Program Analyst, Program Analysis & Review Section (PARS), Rehabilitation Research & Development Service

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 1999

Study Completion (Actual)

September 1, 2002

Study Registration Dates

First Submitted

March 14, 2001

First Submitted That Met QC Criteria

March 15, 2001

First Posted (Estimate)

March 16, 2001

Study Record Updates

Last Update Posted (Estimate)

January 21, 2009

Last Update Submitted That Met QC Criteria

January 20, 2009

Last Verified

January 1, 2001

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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