Chylomicronemia, fat tolerance, and atherosclerosis

Abstract

The development of atherosclerosis in normal persons with normal plasma lipid levels may be directly attributable to the large particle size of the newly absorbed lipids (chylomicrons) appearing in the plasma following fat-rich meals. The severity of the hyper- and macrochylomicronemia is dependent on the amount of fat ingested. Meals composed of fat-free and essentially fat-free foods do not give rise to chylomicronemia and the serum remains clear and free of large particles. A fat tolerance test is described in which the amount of fat administered (in the form of heavy cream) is determined by the height and weight of subject. Serial samples of venous blood are taken at hourly intervals following the fat test meal. The degree of chylomicronemia is estimated by the Tyndall light scattered by the serum sample and is quantitatively measured by photo-electric nephelometry. Nephelometric measurements of Tyndall light are translated into units based on a standard solution. The results of the fat tolerance test are plotted as a curve which shows the height and duration of chylomicronemia following the fat test meal. Considerable differences in fat tolerance were observed in normal subjects. Repeated tests at intervals of six months showed that an individual’s fat tolerance tends to remain rather constant. Fat tolerance is believed to be a factor influencing individual susceptibility to the gradual development of atherosclerosis from fat-rich meals. The author wishes to acknowledge with gratitude the advice and assistance of Dr. Louis G. Moench of the University of Utah Medical School and the Salt Lake Clinic.