Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free: https://www.ghostery.com/fr/products/

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site: http://www.youronlinechoices.com/fr/controler-ses-cookies/, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Realytics
Google Analytics
Spoteffects
Optimizely

Targeted advertising cookies

DoubleClick
Mediarithmics

The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at cil-dpo@inra.fr or by post at:

INRA
24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal logo Université Clermont Auvergne & associés

Human Nutrition Unit

Zone de texte éditable et éditée et rééditée

Vascular Function Exploration

Contact : Marie-Anne Verny (Ingénieur, Equipe NutriVasc)

To analyze vascular function and related functional parameters on humans, several methods have been implemented on the technical platform “exploration of vascular function” since 2010. The development of these non-invasive techniques has been performed in collaboration with the Clinical Investigation Centre (CIC) in Clermont-Ferrand (Prof. C. Dubray, Vascular medecine) and the Department of Cardiology at the University Hospital of Clermont-Ferrand (Prof. J.R. Lusson, Dr Nicolas Barber- Chamoux). An engineer from the Human Nutrition Unit, MA Verny, has been trained to these techniques by specialists and is fully competent to realize all the vascular measurements required in clinical trials.

The platform is localized at the CIC.   

Equipment and measurements:

The technical platform is equipped with the following devices to assess vascular function with non-invasive techniques:

 

Vivid S5 echocardiograph (GE)

  • Flow Mediated Dilatation (FMD) and blood flow velocity

In the macro-circulation, endothelial function is evaluated after the induction of reactive hyperemia by measuring FMD and blood flow velocity at the brachial artery with an ultrasound Doppler (VIVID S5 GE).

echographe-Vivid-S5
Suivi par échographie de l’évolution du diamètre de l’artère brachiale suite à l’induction d’une hyperémie post occlusive. Analyse informatique des images.

                                           FMD (%) = ((artery maximum diameter – artery basal diameter)/artery basal diameter)*100

  • Intima/media thickness

The thickness of the carotid intima-media is closely correlated with the occurrence of cardiovascular events. This parameter is measured by ultrasound (VIVID S5).

Epaisseur-intima_média

Endo-PAT 2000 (Itamar Medical Ltd)

In the peripheral arterial beds, endothelial function is assessed after the induction of reactive post occlusive hyperemia using peripheral arterial tonometry (Endo-PAT 2000, Itamar). The measurement of the endothelium-mediated changes in vascular tone is made in the fingertips using a pair of unique plethysmography-based bio-sensors.

The results were expressed as reactive hyperemia index (RHI, %), which correspond to the ratio between the average pulse wave amplitude during hyperemia (60 to 120 s of the post-occlusion period) and the average pulse wave amplitude during baseline in the occluded hand and corrected by the values from the control arm.

Normal: RHI > 1.67
Abnormal: RHI ≤ 1.67

The EndoPAT device also generates the augmentation index (AIx), which is a measure of peripheral microvascular stiffness calculated from the shape of the pulse wave recorded by the probes during baseline. To correct for the independent effect of heart rate, the AIx is adjusted to a heart rate of 75 beats/min (AIx@75 beats/min).  Measures arterial stiffness is considered an independent risk factor for CVD not necessarily correlated to endothelial function. Lower AI values (including negative results) reflect better arterial elasticity.

endo-PAT-2000
Capteur enregistrant les modifications du tonus vasculaire au niveau de l’extrémité de l’index.
Signal PAT, en haut avec occlusion et hyperémie réactive ; en bas sans intervention (doigt témoin).

Periflux (Perimedes SA)

Changes in microcirculation are measured by the Flow Laser Doppler techniques using the Laser Doppler PF 5010 (Perimed). The Laser Doppler analyses overall blood perfusion at a defined point. It is an excellent technique to monitor the changes caused by the induction of post occlusive reactive hyperemia, local heat or iontophoresis.

periflux
Enregistrement signal Périflux
 Installation du volontaire : sonde échographique sur artère brachiale et capteurs laser doppler Periflux sur l’intérieur des mains

SphygmoCor (CPV ATCOR Medical)

Arterial stiffness is considered to be the main factor in arterial aging and a major risk factor for CVD. This parameter is assessed by measuring the velocity of a pulse wave (Pulse Wave Velocity, PWV) between the carotid and femoral artery. The PWV value is proportionally correlated to arterial stiffness.

Sphygmocor
Enregistrement de l’onde de pouls.
Contact :

Marie-Anne Verny

 NutriVasc Team

+33 (0)4 73 62 44 77