Causes and Natural History of Dyslipidemias

  • STATUS
    Recruiting
  • participants needed
    2000
  • sponsor
    National Heart, Lung, and Blood Institute (NHLBI)
Updated on 7 October 2022
atherosclerosis
myocardial infarction
blood test
hypercholesterolemia
cholesterol level
cholesteryl ester transfer protein
dyslipidemia
hyperlipidemia
cholesterol measurement
plasma cholesterol
xanthoma
pcsk9
combined hyperlipidemia
familial hypercholesterolemia

Summary

This study will evaluate people with dyslipidemias - disorders that affect the fat content in the blood. Fats, or lipids, such as cholesterol and triglycerides, are carried in the blood in particles called lipoproteins. These particles are involved in causing blood vessel diseases that can lead to conditions like atherosclerosis (hardening of the arteries) or heart attack. Participants will undergo accepted medical tests and procedures to evaluate their condition. Most of the test results are helpful in making a diagnosis and in guiding treatment.

People with lipid disorders are eligible for this study. Representative types of patients include those with:

  • Plasma cholesterol levels greater than 200 mg/dl or less than 120 mg/dl
  • Plasma LDL-C levels greater than 130 mg/dl or less than 70 mg/dl
  • Plasma HDL-C levels greater than 70 mg/dl or less than 25 mg/dl
  • Unusual cholesterol deposits or xanthomas (nodules of lipid deposits on the skin)

Children under 2 years of age are excluded from the study.

Participants will undergo some or all of the following procedures:

  • Plasma evaluation. Apolipoproteins (plasma proteins involved in metabolism of cholesterol, triglycerides, phospholipids, and proteins in the blood) and enzymes involved in lipid metabolism are measured.
  • Fat biopsy. A small sample of fat tissue is collected for examination. For this test, an area on the buttock or abdominal wall is numbed. A needle is inserted into the fat, and a small amount of tissue is sucked out by a syringe.
  • Leukapheresis. White blood cells are collected to help diagnose the lipid disorder. For this test, blood is collected through a needle in an arm vein, similar to donating blood. The blood circulates through a machine that separates it into its components, and the white cells are removed. The rest of the blood is returned to the body, either through the same needle or through another needle in the other arm.
  • Skin biopsy. Skin cells are collected for study. The cells are grown in the laboratory and the amount of cholesterol that enters or leaves the cells is measured, providing information on abnormalities in cholesterol transport. For this test, an area of skin is numbed with an anesthetic and a small circular area is removed, using a skin punch instrument similar to a sharp cookie cutter.
  • Heparin infusion study. Heparin, a blood thinner, releases enzymes that break down fat in the blood. Lipase activity (breakdown of fats) in the blood is measured following the injection of heparin into a vein.

Description

The lipoprotein transport system is vital to the delivery of the hydrophobic fats that are carried in the aqueous environment of the blood. The lipoprotein particles that comprise this system are polydisperse and contain triglycerides, free and esterified cholesterol, phospholipids and proteins. Inborn errors in the lipoprotein transport system lead to alterations in both the steady state concentrations of the various lipoproteins and in the metabolism of these particles. These inborn errors lead to both hyperlipoproteinemia and hypolipoproteinemia. Profound changes in the ambient lipoprotein concentrations have a variety of clinical manifestations. The present study protocol is designed to permit a full plasma evaluation of the lipids, lipoproteins and apolipoproteins, in patients with potential genetic defects in these processes. We will use a variety of research plasma assays. These specialized plasma assays are necessary to correctly diagnose and treat patients that present with the more unusual disorders of lipid metabolism; these patients cannot be diagnosed by standard, CLIA- Certified assays and may require tissue or blood cells for diagnosis and adequate treatment. The study population will include patients which are referred to the Lipid Service, Cardiovascular Branch, NHLBI from private care providers, academic institutions or the NHLBI-MDB website, with any of the following potential lipid abnormalities or clinical stigmata associated with dyslipoproteinemias: a) increased plasma levels of cholesterol, triglycerides, HDL-cholesterol or LDL-cholesterol b) decreased plasma concentrations of cholesterol and HDL-cholesterol c) postprandial hyperlipidemia or d) eruptive xanthomas, xanthelasma, tuberous or tendinous xanthomas, or corneal opacities.

Details
Condition Hypercholesterolemia, Atherosclerosis
Clinical Study IdentifierNCT00353782
SponsorNational Heart, Lung, and Blood Institute (NHLBI)
Last Modified on7 October 2022

Eligibility

Yes No Not Sure

Inclusion Criteria

Children >= 2 years of age and >12 kg and adults
Dyslipidemia subjects of interest the group
The following is a representative list of the types of patient presentations with
dyslipidemia and potential diagnoses eligible for this protocol
Plasma cholesterol levels >200 mg/dl or <120 mg/dl includes patients with diagnoses
such as familial hypercholesterolemia, familial combined hyperlipidemia
sitosterolemia, lipoprotein lipase, hepatic lipase or apo-CII deficiency, and
dysbetalipoproteinemia
Plasma LDL-C levels >130 mg/dl or <70 mg/dl includes patients with diagnoses such as
familial hypercholesterolemia, PCSK9, apo3500, familial combined hyperlipidemia
sitosterolemia, dysbetalipoproteinemia, abetalipoproteinemia and
hypobetalipoproteinemia
Plasma HDL-C levels >70 mg/dl or <25 mg/dl includes patients with deficiency of
cholesteryl ester transfer protein, lecithin cholesterol acyltransferase, phospholipid
transfer protein, lipoprotein lipase, hepatic lipase, or apo-CII, ANGPTL3, and Tangier
disease
Plasma triglyceride levels >150 mg/dl includes patients with deficiency of lipoprotein
lipase, hepatic lipase or apoC-II, GPIHBP1, LMF1, dysbetalipoproteinemia, Type I, Type
IV and Type V hyperlipidemia
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer  to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact

site

Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider

Loading...

Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 

 • 

Private

Reply by • Private
Loading...

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.
Loading...

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note