High Density Lipoprotein (HDL) Functionality in Metabolic Syndrome

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00716300
Recruitment Status : Unknown
Verified February 2009 by The University of Western Australia.
Recruitment status was:  Recruiting
First Posted : July 16, 2008
Last Update Posted : February 18, 2009
Information provided by:
The University of Western Australia

Brief Summary:
The aim of the study is to examine the kinetic, anti-oxidant, anti-inflammatory and cellular cholesterol efflux properties of high-density lipoprotein (HDL) in subjects with the metabolic syndrome (MetS) and lean individuals.

Condition or disease
Metabolic Syndrome X

Detailed Description:

Background and Purpose of This Study:

The metabolic syndrome (MetS) is characterized by impaired glucose and insulin metabolism (insulin resistance), abnormal body fat distribution called central obesity (a pot belly) and high blood pressure. People with the metabolic syndrome have markedly increased risk of heart disease which is mainly attributed to the abnormal fat metabolism and its associated metabolic disorders. Therefore, understanding of the body fat disorder is important to reduce the incidence and severity of heart disease.

Fats in the blood originate from dietary sources and from production by the liver. They are then delivered into peripheral body cell for utilization or storage. A particular protein, called high-density lipoprotein (HDL) apolipoprotein (apo) A-I, is an important fat carrier responsible for transporting excess fat from cells, via the bloodstream, back to the liver. Low HDL-apoA-I concentration is related to increased risk of heart disease. Subjects with MetS have reduced level of apoA-I and we wish to test the hypothesis that it is responsible for the impaired movement of fat from the periphery to the liver. Recent evidence suggests that the functionality of HDL, including anti-oxidant, anti-inflammatory and cholesterol efflux properties, is also important in preventing the development of heart disease. However, these function tests have not yet been investigated extensively in MetS.

Consequently, we wish to examine the transport and anti-atherogenic properties of HDL in subjects with MetS and compare these with normal lean subjects. Such findings would be of significant clinical importance in the understanding of the diverse role of HDL-apoA-I in reducing or preventing the progression of heart disease.


Patients with MetS or lean individuals will be recruited for the study via newspaper advertisements. Following informed consent and once found suitable for participation, 15 men with MetS and 15 lean men will be enrolled. We will give the participants a harmless substance called a stable (non-radioactive) isotope. The isotope will trace the speed at which apoA-I is released into the blood (production) and are removed from the bloodstream (clearance) by the liver.

Participants will be asked to fast (only water allowed) for 12 hours prior to the isotope study. The stable isotope will be administered by intravenous injection in the form of a clear fluid (total volume approximates 15 to 25ml, 1-1.5 tablespoons). A small plastic tube (a cannula) will be placed into a vein in the arm, from where a total of 160mll (10.5 tablespoons) of blood will be obtained. The isotope study lasts 10 hours, during which participants will rest quietly and be allowed water only. At the end of the study day, participants will be given a meal and will be allowed home by taxi or family transport.

These studies will allow us to measure the metabolic action of apolipoprotein A-I, thereby gaining a better understanding of the mechanisms that leads to abnormal blood fat levels in those with MetS. To complete this study, each participant is required to attend 7 visits over a 6-week period.


All participants will receive health education, as well as information on personal health status and a review of heart risk factors.

Study Type : Observational
Estimated Enrollment : 30 participants
Observational Model: Case Control
Time Perspective: Cross-Sectional
Official Title: Functional Studies of High Density Lipoprotein in the Metabolic Syndrome
Study Start Date : July 2008
Estimated Primary Completion Date : June 2009
Estimated Study Completion Date : December 2009

Resource links provided by the National Library of Medicine

obese and insulin resistant subjects
lean and normolipidaemic subjects

Biospecimen Retention:   Samples With DNA
DNA plasma

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population
15 men with features of the metabolic syndrome 15 age-matched normolipidaemic men

Inclusion Criteria:

MetS :the presence of at least three of the following:

  • waist circumference > 102 cm, triglycerides > 1.7 mmol/L, HDL cholesterol < 1.05 mmol/L
  • blood pressure ≥ 130/ ≥ 85 mmHg
  • fasting glucose > 6.1 mmol/L

Lean control:

  • BMI < 25 kg/m2
  • waist circumference < 102 cm
  • triglycerides < 1.0 mmol/L
  • HDL-cholesterol > 1.3 mmol/L

Exclusion Criteria:

  • subjects with plasma LDL-cholesterol > 5 mmo/L
  • diabetes mellitus (defined by oral glucose tolerance test)
  • genetic hyperlipidaemia (e.g. FH)
  • consumption of > 30 g alcohol/day
  • apolipoprotein E2/E2 genotype
  • macroproteinuria
  • creatinaemia ( > 120 umol/L)
  • hypothyroidism
  • hepatic dysfunction (AST or ALT > 2x ULN)
  • major systemic illness and use of steroids or other agents that may influence lipid metabolism
  • cardiovascular event within the past 6 months
  • subjects on hypocaloric diets
  • anaemia; any significant illness that in the opinion of reviewing physician would bear on the study (e.g. heart murmur or psychiatric conditions)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00716300

Contact: Dick C Chan, PhD 61-8-92240268

Australia, Western Australia
University of Western Australia Recruiting
Perth, Western Australia, Australia, 6000
Contact: Dick C Chan, PhD    61-8-92240268   
Sponsors and Collaborators
The University of Western Australia
Principal Investigator: Gerald F Watts, MBBS The University of Western Australia

Responsible Party: Prof Gerald F Watts, University of Western Australia Identifier: NCT00716300     History of Changes
Other Study ID Numbers: DC-HDL2008
First Posted: July 16, 2008    Key Record Dates
Last Update Posted: February 18, 2009
Last Verified: February 2009

Keywords provided by The University of Western Australia:
HDL kinetics
Anti-inflammatory and anti-oxidation studies
30 subjects recruited (15 MetS and 15 lean controls)

Additional relevant MeSH terms:
Metabolic Syndrome X
Pathologic Processes
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases