Conjugated Linoleic Acid Supplementation Study (CLASS)

November 12, 2015 updated by: University of Aberdeen

Effects of cis9,trans11 Conjugated Linoleic Acid on Platelet Function, Markers of Haemostasis and Inflammation on Humans

Cardiovascular disease is a major cause of mortality worldwide resulting in one out of three global deaths. One of the main characteristics of cardiovascular disease is impaired blood flow and increased formation of clots. Platelets are clot-forming cells responsible for prevention of bleeding. However, in disease state they may be overly activated and tend to stick to each other, promoting blood clots and blockage of vessels.

Conjugated linoleic acids (CLA) are unique fatty acids present in dairy food products and beef which would help to prevent platelets from clotting and thus help to prevent cardiovascular disease. However, the mechanisms by which those fatty acids affect platelet function are not yet fully understood. We designed a human intervention study assessing the mechanisms by which CLA beneficially affect platelet function and markers of haemostasis and inflammation in humans.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Despite being trans fatty acids, dietary conjugated linoleic acids( CLA) have been associated with decreased atherogenesis, beneficial effects on insulin sensitivity , glucose and lipid profile and body composition in animal studies.Todate only few studies have studied the effects of the two individual CLA isomers on body composition , lipoprotein metabolism immune function , inflammation , insulin sensitivity and oxidative stress in humans.

A previous study revealed that both cis9,trans11 and trans10,cis12 CLA, as well as CLA mix, significantly decreased agonist-induced platelet aggregation and TxB2 production ex vivo compared with linoleic acid. No effect on agonist-induced platelet aggregation or other blood clotting parameters in healthy female volunteers was observed upon supplementation with 3.9 g/d CLA, compared with sunflower oil, but this may have been due to the low number of subjects participating in this study.

Indeed, supplementation with 13.0 g/day of CLA mix - 50:50 blend, compared with placebo oil, significantly decreased fibrinogen levels in type 2 diabetes patients, and fibrinogen and plasminogen activator inhibitor-1 levels were significantly lower upon intervention with CLA milk (4.7 g/d cis9,trans11 CLA and 0.4 g/d trans10,cis12 CLA), compared with CLA mix (2.3 g/d cis9,trans11 CLA and 2.2 g/d trans10,cis12 CLA), and lower compared with olive oil, in postmenopausal women.Thus overall evidence indicates that especially the cis9,trans11 CLA isomer may prevent platelet activation and aggregation, and possibly display anticoagulant properties. However, so far this has not been assessed in detail.

In this study we assess effects of supplementation of cis9,trans11 CLA-rich oil on platelet function by measuring not only platelet aggregation but also in vitro coagulation and platelet activation in healthy overweight humans. In addition, we examine the effects of CLA supplementation on plasma and cellular marker of inflammation and oxidative stress.

Study Type

Interventional

Enrollment (Actual)

50

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
    • Scotland
      • Aberdeen, Scotland, United Kingdom, AB21 9SB
        • Rowett Institute of Nutrition and Health

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

30 years to 74 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:• Healthy men and women aged 35-74 years

  • blood pressure below 160/90 mmHg;
  • fasting plasma glucose < 7 mmol/L;
  • total cholesterol < 8 mmol/L,with cholesterol/HDL ratio < 6 and/or ASSIGN score < 20%)
  • platelet count > 170x109/L
  • haematocrit above 40 % for males and above 35 % for females
  • haemoglobin above 130 g/L for males and above 115 g/L for females
  • having a 10-20% risk for developing cardiovascular disease within the next 10 years based on the ASSIGN calculation (http://cvrisk.mvm.ed.ac.uk/index.htm) including the following factors: age, gender, number of cigarettes smoked per day, Scottish Index of Multiple Deprivation (SIMD)/postcode, systolic blood pressure, levels of total and HDL cholesterol and family history of cardiovascular disease or having at least one additional risk factor such as being over 50 years old, BMI above 25 kg/m2, elevated triglyceride levels (> 1.7 mmol/L) or elevated glucose levels (> 5.6 mmol/L);

Exclusion Criteria:Exclusion criteria Subjects are excluded if

  • They are regularly taking aspirin or aspirin-containing drugs, or other anti-inflammatory drugs;
  • They are taking drugs or herbal medicines known to alter platelet function or the haemostatic system in general;
  • They are diagnosed with diabetes, hypertension, renal, hepatic, haematological disease or coronary heart disease;
  • They are undertaking more than 6 hours vigorous exercise per week
  • They are pregnant (or planning to become pregnant) or lactating;
  • They have given a pint of blood for transfusion purposes within the last month;
  • They have unsuitable veins for blood sampling;
  • They are inability to understand the participant information sheet or inability to speak, read and understand the English language.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: cis9,trans 11 CLA oil
50 volunteers on cross over design , receiving 4g/day of cis9,trans11 CLA
Dietary supplement: Placebo oil
Placebo oil of 4g/day
Placebo Comparator: Placebo oil
50 volunteers cross over design, placebo oil 4g/day
Dietary supplement: Placebo oil
Placebo oil of 4g/day

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change of expression of P-selectin and fibrinogen receptor activation on platelets by flow cytometry
Time Frame: At 2 weeks
Using fluorescently-conjugated monoclonal antibodies and whole blood flow cytometry after ex vivo stimulation with adenosine diphosphate (ADP), thrombin receptor-activating peptide (TRAP) P-selectin expression as early marker of platelet activation Activated fibrinogen receptor as late marker of platelet activation
At 2 weeks
Change of in vitro bleeding time using the Platelet Function Analyzer (PFA-100)
Time Frame: At 2 weeks supplementation
Using collagen-epinephrine coated cartridges Using collagen-adenosine diphosphate coated cartridges
At 2 weeks supplementation
Change of coagulation marker assessed as fibrinogen levels in plasma
Time Frame: At 2 weeks supplementation
Using semi-automated coagulometer using fibrinogen assay according to Clauss method
At 2 weeks supplementation

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in light transmission aggregometry of platelet rich plasma induced by collagen and arachidonic acid
Time Frame: At 2 weeks supplementation
Using a Helena Platelet Aggregation Chromogenic Kinetics System-4 (PACKS-4) light transmission aggregometer
At 2 weeks supplementation
Change in plasma levels of von Willebrand factor (vWF), soluble ICAM (s-ICAM) and soluble P-selectin (sP-selectin) as markers of endothelial activation
Time Frame: At 2 weeks supplementation
Using enzyme-linked immunoabsorbent assay (ELISA) in plasma
At 2 weeks supplementation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Aberdeen

Investigators

  • Principal Investigator: Baukje De Roos, PhD, Univeristy of Aberdeen

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2010

Primary Completion (Actual)

November 1, 2012

Study Completion (Actual)

November 1, 2012

Study Registration Dates

First Submitted

November 2, 2010

First Submitted That Met QC Criteria

November 3, 2010

First Posted (Estimate)

November 4, 2010

Study Record Updates

Last Update Posted (Estimate)

November 13, 2015

Last Update Submitted That Met QC Criteria

November 12, 2015

Last Verified

November 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RINH_1000

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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