HypertensionNCT00331370
Hypertension Related Damage to the Microcirculation in South Asian: Emergence, Predictive Power and Reversibility
A study testing GP training and Health Education in people with Hypertension and Diabetes, run by Aga Khan University at 1 site in Pakistan.
Trial summary
Damage to very small blood vessels is a consequence, but can also precede high blood pressure. Such damage, measured by disturbances in the vessels in the retina (back of the eye) is a strong predictor of heart disease and stroke. Read more about this study
- Who is it for?
- Ages 9 years and older
- Conditions the study is for
- Hypertension, Diabetes, Cardiovascular Disease
- What is being tested?
- GP training and Health Education
- Type of treatment
- Lifestyle or therapy programme
- How many people
- 2,880 participants
- Where
- 1 sitePakistan
- Study dates
- May 2006to Jun 2009
- 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 9 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- All subjects aged 9 years or over residing in randomly selected communities
Who cannot join
- Pregnancy
- Those who have severe co-morbid conditions
- Patients with known history of glaucoma will be excluded from our study because instillation of mydriatic drops was thought to be hazardous for them.
Trial locations and contacts
1 site in 1 country.
Pakistan1 site
Aga Khan University
Karachi, Sindh, 74800
Tazeen H Jafar, MD, MPH, 0092-21-4930051 ext. 4818, tazeen.jafar@aku.edu
Muhammad Saleem Khan, MSc Epi&Bio, 0092-21-4930051 ext. 4936, muhammad.saleem@aku.edu
About this study
Official title: Hypertension Related Damage to the Microcirculation in South Asian: Emergence,Predictive Power and Reversibility
Damage to very small blood vessels is a consequence, but can also precede high blood pressure. Such damage, measured by disturbances in the vessels in the retina (back of the eye) is a strong predictor of heart disease and stroke. South Asian people have one of the highest rates of hypertension in the world (30% in adults). In Pakistan, this is usually severe, undetected and untreated. The Wellcome Trust has already funded a study of blood pressure control in adults and children in this population. We propose a substudy, taking photographs of the retina and making measurements of the vessels, to determine whether such blood pressure related changes occur at an early age in young children with a family history of high blood pressure compared to those without, whether such changes predict an increase in blood pressure over time, and whether, in adults, such changes can be reversed by blood pressure treatment. The hypothesis of our study is: young offspring of South Asian people with hypertension have a disturbed microcirculation, as assessed by abnormalities of retinal vessels, compared to offspring of normotensive parents. Our 2nd hypothesis is: Abnormal retinal vascular geometry will improve proportionately to achieved reductions in BP.
Read the detailed description
Background
The role of the microcirculation is increasingly being recognized in the etiopathogenesis of cardiovascular disease. Delays in this recognition are in part due to the difficulty of studying the microcirculation non-invasively, in large numbers of individuals. Retinal vessels provide an easily accessible "window" to the microcirculation. Abnormalities of the retinal vasculature have been shown to be associated with cardiovascular risk factors and all cause mortality. Non-invasive assessment of the retinal circulation presents a valuable opportunity to study the structure and function of the microvasculature
Aims of the project
To compare geometry of retinal microvasculature of 1) hypertensive vs normotensive adults, 2) children aged 10 to 14 years of hypertensive parent (test group) versus normotensive parent (control group), and, 3) to assess the impact of blood pressure lowering on these changes over 2 years.
Primary outcome would be abnormal retinal geometry defined as the composite outcome of a) abnormal arteriolar length: diameter ratios (a measure of relative arteriolar narrowing), b) narrowed branching angles (an indicator of arteriolar rarefaction), or c) disturbed junction exponents (a marker of endothelial dysfunction.
Significance of the study
If successful, this work could be extended to address future questions, including the predictive value of these abnormalities for development of diabetes and hypertension as well as CVD; to explore further the role of microvascular disturbances in disease etiology, and to assess the impact of drug therapy on these abnormalities and their relationship to outcomes in the South Asian population
- Conditions
- Hypertension, Diabetes, Cardiovascular Disease, Retinopathy
- Being tested
- GP training and Health Education
- Medical subject headings
- Hypertension, Diabetes Mellitus, Cardiovascular Diseases, Retinal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GP training and Health EducationBehavioural
What is being measured
The primary outcome is the main question the study is designed to answer.
Primary outcome would be abnormal retinal geometry defined as the composite outcome of a) abnormal arteriolar length: diameter, b) narrowed branching angles, or c) disturbed junction exponents.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 May 2006 (estimated)
- Study startMay 2006
- Study completionJun 2009
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypertensionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Randomised
- Intervention model
- Factorial
- Masking
- Single blind
- Enrolment
- 2,880 participants
Sponsor and investigators
- Lead sponsor
- Aga Khan University
- Sponsor type
- University, hospital or other
- Collaborators
- Imperial College London
- Investigators
- Tazeen H Jafar, MD, MPH, Principal investigator, Aga Khan UniversityNish Chaturvedi, MD, MFPHM, Study chair, Imperial College LondonAlun Hughes, MD, Phd, Study chair, Imperial College LondonJuanita Hatcher, Phd, MSc, Study chair, Aga Khan UniversitySimon Thom, MD, FRCP, Study chair, Imperial College LondonKhabir Ahmad, MD, MSc, Study chair, Aga Khan UniversityMuhammad Saleem Khan, MSc Epi&Bio, Study chair, Aga Khan University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00331370
- Sponsor's protocol ID
- DHCPP00493
- Status last verified
- May 2006
- First submitted
- 30 May 2006
- Last updated
- 31 May 2006
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 31 May 2006. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hypertension Related Damage to the Microcirculation in South Asian: Emergence,Predictive Power and Reversibility
- ClinicalTrials.gov ID
- NCT00331370
- Acronym / sponsor ID
- DHCPP00493
- Conditions
- Hypertension, Diabetes, Cardiovascular Disease, Retinopathy
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 2,880 participants
- Lead sponsor
- Aga Khan UniversityUniversity, hospital or other
- Collaborators
- Imperial College London
- Study start
- May 2006
- Study completion
- Jun 2009
- First posted
- 31 May 2006 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Damage to very small blood vessels is a consequence, but can also precede high blood pressure. Such damage, measured by disturbances in the vessels in the retina (back of the eye) is a strong predictor of heart disease and stroke. South Asian people have one of the highest rates of hypertension in the world (30% in adults). In Pakistan, this is usually severe, undetected and untreated. The Wellcome Trust has already funded a study of blood pressure control in adults and children in this population. We propose a substudy, taking photographs of the retina and making measurements of the vessels, to determine whether such blood pressure related changes occur at an early age in young children with a family history of high blood pressure compared to those without, whether such changes predict an increase in blood pressure over time, and whether, in adults, such changes can be reversed by blood pressure treatment. The hypothesis of our study is: young offspring of South Asian people with hypertension have a disturbed microcirculation, as assessed by abnormalities of retinal vessels, compared to offspring of normotensive parents. Our 2nd hypothesis is: Abnormal retinal vascular geometry will improve proportionately to achieved reductions in BP.
Detailed description
Background
The role of the microcirculation is increasingly being recognized in the etiopathogenesis of cardiovascular disease. Delays in this recognition are in part due to the difficulty of studying the microcirculation non-invasively, in large numbers of individuals. Retinal vessels provide an easily accessible "window" to the microcirculation. Abnormalities of the retinal vasculature have been shown to be associated with cardiovascular risk factors and all cause mortality. Non-invasive assessment of the retinal circulation presents a valuable opportunity to study the structure and function of the microvasculature
Aims of the project
To compare geometry of retinal microvasculature of 1) hypertensive vs normotensive adults, 2) children aged 10 to 14 years of hypertensive parent (test group) versus normotensive parent (control group), and, 3) to assess the impact of blood pressure lowering on these changes over 2 years.
Primary outcome would be abnormal retinal geometry defined as the composite outcome of a) abnormal arteriolar length: diameter ratios (a measure of relative arteriolar narrowing), b) narrowed branching angles (an indicator of arteriolar rarefaction), or c) disturbed junction exponents (a marker of endothelial dysfunction.
Significance of the study
If successful, this work could be extended to address future questions, including the predictive value of these abnormalities for development of diabetes and hypertension as well as CVD; to explore further the role of microvascular disturbances in disease etiology, and to assess the impact of drug therapy on these abnormalities and their relationship to outcomes in the South Asian population
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Single blind
Who may qualify
- Ages
- 9 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- All subjects aged 9 years or over residing in randomly selected communities
Key exclusion criteria (3 listed)
- Pregnancy
- Those who have severe co-morbid conditions
- Patients with known history of glaucoma will be excluded from our study because instillation of mydriatic drops was thought to be hazardous for them.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| GP training and Health Education | Behavioural | – |
Primary outcome
Primary outcome would be abnormal retinal geometry defined as the composite outcome of a) abnormal arteriolar length: diameter, b) narrowed branching angles, or c) disturbed junction exponents.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 May 2006.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tazeen H Jafar, MD, MPH principal investigator
Aga Khan University
Nish Chaturvedi, MD, MFPHM study chair
Imperial College London
Alun Hughes, MD, Phd study chair
Imperial College London
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing GP training and Health Education in people with Hypertension and Diabetes, run by Aga Khan University at 1 site in Pakistan.
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 1 inclusion and 3 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: status not confirmed, as of the sponsor's last update on 31 May 2006. 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 Pakistan. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Tazeen H Jafar, Md,MPH (0092-4930051 ext. 4818, tazeen.jafar@aku.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Primary outcome would be abnormal retinal geometry defined as the composite outcome of a) abnormal arteriolar length: diameter, b) narrowed branching angles, or c) disturbed junction exponents.. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 31 May 2006; AzTrials last refreshed its copy on 8 Nov 2026.