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Type 1 Diabetes MellitusNCT01045005

Doppler Ultrasound Investigation of Microcirculations

A study testing Administration ofOxygen and carbon dioxide and Administration of Oxygen and carbon dioxide in people with Type 1 Diabetes Mellitus, run by Queen's University, Belfast at 1 site in United Kingdom.

Withdrawn

Withdrawn. The study stopped before anyone enrolled.

Official record
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Trial summary

The investigators aim to show that quantitative analysis of doppler flow velocity waveforms i.e. ultrasound which is a non-invasive and very safe means of assessing blood flow; recorded in the proximity of terminal microvascular beds of interest, (i.e. Read more about this study

Who is it for?
Ages 18 to 60 yearsHealthy volunteers can take part
Conditions the study is for
Type 1 Diabetes Mellitus
What is being tested?
Administration ofOxygen and carbon dioxide and Administration of Oxygen and carbon dioxide
Could I receive a placebo?
No, everyone receives an active treatment
How many people
0 participants
Where
1 siteUnited Kingdom
Study dates
Jan 2006to Jul 2010
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 60 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • To be eligible for study patients must be older than 18 years.
  • All patients will have undergone an extensive clinical evaluation performed at the Belfast City Hospital diabetes clinic that includes retinal photography.
  • Patients will be eligible for the study if they are in stable control of their diabetes with a haemoglobin of A1c between 6.5 and 10%.
  • Patients will be eligible if they have background retinopathy. The control subjects will be healthy individuals; and will be age and sex matched for the disease population.

Who cannot join

  • Patients with proliferative retinopathy or those undergoing laser therapy will be excluded from study. This would make assessment of the retinal arteriolar structure very difficult.
  • Patients will also be excluded if they have hypertension (a blood pressure >140/90mmHg) or taking antihypertensive drugs. The investigators know that the presence of hypertension will have an effect on the retinal waveforms and structure.
  • Patients will also be excluded if they have any significant renal disease (GFR <60ml min) or a history of cardiovascular or cerebrovascular complications.
  • Patients with microalbuminuria (>3 g/min) can be included in the study but would be asked to stop their medication (e.g. ACE inhibitor) for 5 days prior to the study period. It should be mentioned that the risk associated with stopping this effective medication for such a period of time is minimal. This has been common practice in our department in a number of previous studies, and in the published literature. This will be clearly communicated to the patient in the patient information sheet, in the patient consent form; and in the discussion/process of obtaining informed consent with the patient

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site
  • Department of Therapeutics and Pharmacology, Queens University Belfast

    Belfast, Antrim, BT9 7RL

Other trials in United Kingdom

About this study

Official title: Doppler Ultrasound Investigation of Ocular and Skeletal Microcirculations in Health and Disease

The investigators aim to show that quantitative analysis of doppler flow velocity waveforms i.e. ultrasound which is a non-invasive and very safe means of assessing blood flow; recorded in the proximity of terminal microvascular beds of interest, (i.e. the forearm and ocular circulation) can sensitively detect and track local changes in microvascular haemodynamics i.e. the function of the small blood vessels that are found in the back of the eye and in the forearm.

The investigators also aim to relate change in the doppler spectral flow velocity waveform i.e. the ultrasound signal, in the central retinal artery to changes in geometry and tone of the vasculature (or changes in the structure and function of small blood vessels) in response to inhaled oxygen and carbon dioxide. The geometry and tone of the vasculature (or Blood Vessels) can be measured by taking photographs of the back of the eye.

Read the detailed description

Diabetes mellitus significantly increases the risk for both small and large blood vessel complications e.g. diabetic eye problems and coronary heart disease. Vital organs such as the eye, kidney, heart and brain represent well- recognized preferential targets in patients with diabetes mellitus. The presence of such end-organ damage powerfully influences cardiovascular risk and the benefits of therapeutic interventions. Unfortunately, by the time symptoms develop or events occur as manifestations of target-organ damage, the disease process is already at an advanced stage. Although not traditionally viewed as an end-organ, it is altered structure and function of arterial small blood vessels that acts as the substrate for accelerated disease development and the increased occurrence of vascular events in patients with diabetes mellitus. The ability to detect and monitor sub-clinical damage, representing the cumulative and integrated influence of all risk factors in impairing arterial wall integrity, holds potential to further refine cardiovascular risk stratification and enable early intervention to prevent or attenuate disease progression.

Data derived from analysis of arterial waveforms, that marks the presence of impaired pulsatile function in the arterial system, has been shown to predict future cardiovascular risk. As consistent abnormalities in the arterial pulse wave shape have been recognized for many years in diabetic subjects there has been a growing interest in quantifying changes in the pulse contour to provide information about the status of the vasculature in diabetes. These original observations have been confirmed in more recent studies in patients with type 1 and type 2 diabetes mellitus and are detected prior to the development of clinical complications of the disease.

Analysis of the pulse contours recorded from sites in large conduit arteries identify structural and functional abnormalities predominantly in the systemic microvasculature, as small arteries and arterioles are recognised as the major sites for wave reflection that alters pulse contour morphology. It is recognised that techniques providing a global assessment of the circulation may not capture and cannot localise findings to a specific site or target-organ of interest in the arterial system. Microcirculation is a collective term for the smallest segments of the vascular system and is a major site of control of vascular resistance. It includes arterioles and capillaries and is considered to be a continuum rather than a distinct site of resistance control. Importantly, it is recognised as sites were the earliest manifestations of cardiovascular disease, especially inflammatory processes occur. The microvasculature may therefore constitute a preferential target or be primarily involved in the pathogenesis of disease and represents an important regional target for therapeutic interventions. Further, retinal photography and standardised grading provides a unique opportunity to study retinal microvascular characteristics including retinopathy and change in arteriolar (or blood vessel) structure and function. Improved methods of assessment to study the retinal microvascular network holds potential to improve prediction of risk, identify high risk groups and act as a window to monitor the effects of possible drug interventions.

Being tested
Administration ofOxygen and carbon dioxide, Administration of Oxygen and carbon dioxide
Keywords
Type 1 diabetes, Endothelial dysfunction, Doppler Ultrasound Velocity Waveforms
Medical subject headings
Diabetes Mellitus, Type 1

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Administration ofOxygen and carbon dioxideOther

    Inhalation of 100% oxygen and 4% carbon dioxide. This is non-harmful/non-toxic and will be given according to protocol previously described in the literature. It will be administered for a maximum of 4 minutes.

  • Administration of Oxygen and carbon dioxideOther

    Inhalation of 100% oxygen and 4% carbon dioxide. This is non-harmful/non-toxic and will be given according to protocol previously described in the literature. It will be administered for a maximum of 4 minutes.

Study groups in NCT01045005
Study groupRoleWhat they receive
Type 1 DiabetesActive comparatorSubjects with type 1 diabetes mellitus who are administered oxygen and carbon dioxide
Receives: Other: Administration of Oxygen and carbon dioxide
Control SubjectsActive comparatorHealthy volunteers administered oxygen and carbon dioxide via respiratory apparatus
Receives: Other: Administration ofOxygen and carbon dioxide

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Doppler Blood flow velocity waveforms measured at rest and after administration of oxygen and carbon dioxide

    Measured: At initial visit and then yearly

Secondary outcomes (1)
  1. Radial Artery pressure waveforms

    Measured: At initial visit and then yearly

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Jan 2010 (estimated)
  2. Study startJan 2006
  3. Primary completionJul 2010
  4. Study completionJul 2010

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Prevention
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
0 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01045005
Sponsor's protocol ID
05060CL-A
Status last verified
Aug 2019
First submitted
6 Jan 2010
Last updated
20 Aug 2019
Results posted
No
Data monitoring committee
Yes

Publications

  • Wright SA, O'Prey FM, Hamilton PK, Lockhart CJ, McCann A, McHenry MT, McGivern RC, Plumb R, Finch MB, Bell AL, McVeigh GE. Colour Doppler ultrasound of the ocular circulation in patients with systemic lupus erythematosus identifies altered microcirculatory haemodynamics. Lupus. 2009 Oct;18(11):950-7. doi: 10.1177/0961203309104865.

    PubMed 19762395
  • Agnew CE, Rea DJ, McCann AJ, Lockhart CJ, Hamilton PK, Quinn CE, McVeigh GE, McGivern RC. Root-MUSIC analysis of nitric oxide-mediated changes in ophthalmic artery blood flow velocity waveforms. Med Eng Phys. 2009 Sep;31(7):799-805. doi: 10.1016/j.medengphy.2009.03.003. Epub 2009 Apr 16.

    PubMed 19375374
  • Lockhart CJ, Hamilton PK, Quinn CE, McVeigh GE. End-organ dysfunction and cardiovascular outcomes: the role of the microcirculation. Clin Sci (Lond). 2009 Feb;116(3):175-90. doi: 10.1042/CS20080069.

    PubMed 19118490
  • Lockhart CJ, Hamilton PK, McVeigh KA, McVeigh GE. A cardiologist view of vascular disease in diabetes. Diabetes Obes Metab. 2008 Apr;10(4):279-92. doi: 10.1111/j.1463-1326.2007.00727.x. Epub 2007 Oct 15.

    PubMed 17941877
  • Hamilton PK, Lockhart CJ, Quinn CE, McVeigh GE. Arterial stiffness: clinical relevance, measurement and treatment. Clin Sci (Lond). 2007 Aug;113(4):157-70. doi: 10.1042/CS20070080.

    PubMed 17623012
  • Lockhart CJ, Gamble AJ, Rea D, Hughes S, McGivern RC, Wolsley C, Stevenson M, Harbinson MT, Plumb RD, McVeigh GE. Nitric oxide modulation of ophthalmic artery blood flow velocity waveform morphology in healthy volunteers. Clin Sci (Lond). 2006 Jul;111(1):47-52. doi: 10.1042/CS20050365.

    PubMed 16499475

Questions about this trial

What is this clinical trial studying?

A study testing Administration ofOxygen and carbon dioxide and Administration of Oxygen and carbon dioxide in people with Type 1 Diabetes Mellitus, run by Queen's University, Belfast at 1 site in United Kingdom.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: withdrawn, as of the sponsor's last update on 20 Aug 2019. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study was withdrawn before enrolling participants, so there are no results.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Doppler Blood flow velocity waveforms measured at rest and after administration of oxygen and carbon dioxide (time frame: At initial visit and then yearly). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01045005, which also lists 6 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Aug 2019.

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