Doppler Ultrasound Investigation of Microcirculations

NCT01045005 | Withdrawn DMC

• 1 other identifier: 05060CL-A
• Study Type: interventional
• Target: N/A
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Type 1 Diabetes Mellitus

Keywords

Type 1 diabetes; Endothelial dysfunction; Doppler Ultrasound Velocity Waveforms

Outcome Measures

Primary Outcomes (1)

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

  At initial visit and then yearly

Secondary Outcomes (1)

• Radial Artery pressure waveforms

  At initial visit and then yearly

Study Arms (2)

Type 1 Diabetes

ACTIVE COMPARATOR

Subjects with type 1 diabetes mellitus who are administered oxygen and carbon dioxide

Other: Administration of Oxygen and carbon dioxide

Control Subjects

ACTIVE COMPARATOR

Healthy volunteers administered oxygen and carbon dioxide via respiratory apparatus

Other: Administration ofOxygen and carbon dioxide

Interventions

Administration ofOxygen and carbon dioxide OTHER

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.

Control Subjects

Administration of Oxygen and carbon dioxide OTHER

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.

Type 1 Diabetes

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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

Sponsors & Collaborators

• Queen's University, Belfast: lead

Study Sites (1)

Department of Therapeutics and Pharmacology, Queens University Belfast

Belfast, Antrim, BT9 7RL, United Kingdom

Location

Related Publications (6)

• 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.

  PMID: 19762395 BACKGROUND

• 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.

  PMID: 19375374 BACKGROUND

• 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.

  PMID: 19118490 BACKGROUND

• 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.

  PMID: 17941877 BACKGROUND

• 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.

  PMID: 17623012 BACKGROUND

• 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.

  PMID: 16499475 BACKGROUND

MeSH Terms

Conditions

Diabetes Mellitus, Type 1

Interventions

Carbon Dioxide

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases

Intervention Hierarchy (Ancestors)

Carbon Compounds, Inorganic; Inorganic Chemicals; Gases; Oxides; Oxygen Compounds

Study Officials

• Gary E McVeigh, MD PhD FRCP

  Queens University Belfast

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 6, 2010
• First Posted: January 8, 2010
• Study Start: January 1, 2006
• Primary Completion: July 1, 2010
• Study Completion: July 1, 2010
• Last Updated: August 20, 2019

Record last verified: 2019-08

Locations

GB (1)