Physiol. Res. 51: 99-105, 2002

The Effect of an Acute Fat Load on Endothelial Function after Different Dietary Regimens in Young Healthy Volunteers

T. ŠEJDA1, J. KOVÁŘ2, J. PIŤHA3, R. CÍFKOVÁ4, E. ŠVANDOVÁ5,
R. POLEDNE2


1Third Department of Internal Medicine, Thomayer Memorial University Hospital, 2Laboratory for Atherosclerosis Research, and 4Department of Preventive Cardiology, Institute for Clinical and Experimental Medicine, 3Postgraduate Faculty of Medicine, 5National Health Institute, Prague, Czech Republic

Received February 2, 2001
Accepted June 6, 2001


Summary
Attention has recently been focused on endothelial function after a single high-fat meal, i.e. on the anticipated direct atherogenic effect of triglyceride-rich lipoproteins. Our study was designed to investigate the effect of a low-fat diet given for four weeks followed by a high-fat diet for another four weeks. At the end of each dietary period, a non-invasive ultrasound investigation of endothelial function of the brachial artery was performed along with laboratory tests. Endothelial function was measured immediately before the dietary load and after three and six hours in 11 healthy volunteers. The results were expressed as percentage of the changes in artery diameter at rest and during hyperemia; the data were processed using computer technology. When compared to the low-fat regimen, the total cholesterol content rose after the high-fat diet from 4.28 mmol/l to 5.15 mmol/l (p<0.05) in the whole group of volunteers. There was no difference between both dietary regimens in baseline triglycerides. The brachial artery dilatation under basal conditions was 5.26±2.88 mm after the high-fat diet compared with the value of 3.13±3.01 mm (p<0.05) after the low-fat diet. When measured individually endothelial function in the whole group of volunteers in the course of the day, the degree of arterial dilatation after one month on low-fat diet was 3.13±3.0 %, 3.88±2.5 % and 5.23±3.3 % at single measurement. When comparing arterial dilatation at two closest measurements, a non-significant trend, p>0.05 was seen in either case. The following values were obtained after one month on the high-fat diet: 5.26±2.9 %, 4.47±1.7 %, and 6.2±3.6 %; again showing a non-significant trend of p>0.05. In this study, a single high-fat meal at the different dietary regimen did not significantly influence the vasoreactivity of the brachial artery in young volunteers.


Key words
Postprandial lipemia · Hypertriglyceridemia · Endothelial dysfunction · Diet

Reprint requests
Tomáš Šejda, MD, Department of Internal Medicine III, Thomayer Memorial University Hospital, Vídeňská 800, 140 59 Prague 4, Czech Republic, e-mail: tomas.sejda@ftn.cz


© 2002 by the Institute of Physiology, Czech Academy of Sciences