Monocentered, randomised, placebo-controlled, double-blind cross-over study on the effect of Conjugated Linoleic Acid (CLA) on fasting and postprandial metabolic parameters and endothelial function in men with PPARγ2 P12A polymorphism and controls
| ISRCTN | ISRCTN91188075 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN91188075 |
| Protocol serial number | N/A |
| Sponsor | Federal Research Centre for Nutrition and Food (BfEL) (Germany) |
| Funders | Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung) (Germany), Federal Ministry of Food, Agriculture and Consumer Protection (Bundesministerium für Ernährung, Landwirtschaft und Verbraucherschutz) (Germany), Cognis GmbH (Germany) |
- Submission date
- 07/06/2007
- Registration date
- 25/07/2007
- Last edited
- 17/12/2009
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Other
Plain English summary of protocol
Not provided at time of registration
Contact information
Scientific
Bundesforschungsanstalt für Ernährung und Lebensmittel, Standort Kiel
Institut für Physiologie und Biochemie der Ernährung
Hermann-Weigmann-Str. 1
Kiel
24103
Germany
| Phone | +49 (0)431 609 2220 |
|---|---|
| juergen.schrezenmeir@bfel.de |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Randomised, double-blind, placebo-controlled, interventional, crossover study. |
| Secondary study design | Randomised controlled trial |
| Scientific title | |
| Study acronym | CLA2 (Conjugated linoleic acid 2) |
| Study objectives | Conjugated Linoleic Acid (CLA) may beneficially affect lipid and glucose metabolism, inflammatory responses and body weight. These aspects are of relevance for subjects afflicted with or prone to develop so called metabolic syndrome, which is characterized by an insulin resistance, dyslipidaemia, essential hypertension and adiposity of the central type and frequently leads to early manifestation of type 2 diabetes mellitus, increased vascular risk and risk of atherosclerosis. Studies of the influence of dietary CLA, namely the individual isomers cis9,trans11-CLA and trans10,cis12-CLA as well as the commercially available 50:50 mixture of these isomers, as compared to linoleic acid as control, on fasting and postprandial metabolism. The study will test if there are genotype-dependent specific effects of the PPARγ2 P12A polymorphism (P12P versus A12A homozygosity). Expression of genes relevant for inflammation and metabolic regulation will be examined in monocytes independent of a PPARγ2 polymorphism. Further parameters to assess atherogenic processes are the expression of adhesion molecules (ICAM, VCAM, E-Selectin). Low Density Lipoprotein (LDL) will be isolated and tested for adhesion molecules expression on endothelial cells. As another study reported that a mixture of CLA isomers impairs endothelial function, this parameter will be determined in our study, with particular attention for the effect of individual isomers. As dietary fats may acutely change endothelial function, this parameter is tested both in the fasting state and following a fat-rich meal. Genotype-dependent specific effects on fat tissue are to be examined by determining the gene expression profile of the subcutaneous fat tissue. Furthermore the effect of CLA on fecal flora will be assessed. |
| Ethics approval(s) | Ethic Committee of the Medical Faculty of the Christian-Albrechts-University of Kiel, (Germany), approved on 13.09.2006 (ref: A151/06) |
| Health condition(s) or problem(s) studied | Not applicable |
| Intervention | All participants will consume, in random order, capsules with either the individual isomers cis9,trans11-CLA and trans10,cis12-CLA as well as the commercially available 50:50 mixture of these isomers, and linoleic acid as control. The material is provided as free fatty acids in capsules. Tocopherol content of the preparations is standardized. Each intervention will last for 4 weeks, interrupted by wash-out periods of 6-9 weeks between the interventions. |
| Intervention type | Drug |
| Phase | Not Specified |
| Drug / device / biological / vaccine name(s) | Conjugated Linoleic Acid |
| Primary outcome measure(s) |
Change of postprandial triglyceride levels (Area Under the Curve [AUC]) after 28 (±2) days supplementation. Postprandial triglyceride levels will be measured at the start of the study and after each intervention period. |
| Key secondary outcome measure(s) |
Measurements for the following will be made at the start of the study and after each intervention period. |
| Completion date | 12/07/2007 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Sex | Male |
| Target sample size at registration | 40 |
| Key inclusion criteria | 1. Healthy male volunteers aged 45-68 2. Homozygosis of PPARγ2 P12A polymorphism 3. Member of the Metabolic Intervention Cohort Kiel (MICK) BMI- matched controls will be recruited. |
| Key exclusion criteria | 1. Participation in a clinical study with a medicament or a medicinal product within the last 30 days or simultaneous participation in another clinical examination 2. Inability to understand and to comply with the study protocol 3. Known metabolic or gastro-intestinal diseases, which affect the absorption, metabolism or excretion of food or food components 4. Condition after surgery of the gastro-intestinal tract, which affect gastro-intestinal motility 5. Hemoglobin <12 g/dL 6. Latex allergy 7. Diabetes (fasting glucose levels >125 mg/dl after repeated determination) 8. Surgery within the last 3 months, which still affects the current state of health 9. Intake of nitrate and/or calcium antagonists and/or alpha-blockers, which affect the blood pressure 10. Deformation of finger tips, which inhibits correct recording of EndoPAT 11. Illness of thyroid gland, which has metabolic and/or cardiovascular effect 12. Known hepatitis B, hepatitis C, HIV infection or chronic liver damage 13. Kidney insufficiency 14. Drug or alcohol abuse 15. Intake of drugs affecting the absorption, metabolism or excretion of food components or the gastro-intestinal motility 16. Intake of hormone preparations, particularly cortisone 17. Eating disorders, anorexia, bulimia, unusual outsider dietary habits 18. Psychiatric disorders, epilepsy, risk of suicide 19. For those who participate in adipose tissue biopsy, additionally: 19.1. Known allergies against local anaesthetics 19.2. Heart insufficiency 19.3. Coagulation dysfunction/consumption of drugs which may cause such dysfunctions |
| Date of first enrolment | 11/10/2006 |
| Date of final enrolment | 12/07/2007 |
Locations
Countries of recruitment
- Germany
Study participating centre
24103
Germany
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not provided at time of registration |
| IPD sharing plan |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | results | 18/08/2009 | Yes | No |
