Use of I 131-labelled fat in the study of lipid handling in patients with coronary artery disease

Abstract

In order to study the handling or disposition of lipid in patients with coronary artery disease, fifty-one normotensive male subjects between the ages of nineteen and fifty-three received a test meal which contained a small amount of radioactive I 131-labelled glyceryl trioleate. Serial blood samples were drawn after the test meal in order to determine the total circulating radioactivity contained in the whole blood and in the trichloroacetic acid precipitable fraction. These were reported as percentage of ingested dose. The series included twenty “normal” subjects and twenty-one patients, of comparable ages, with documented myocardial infarctions. At peak time and at twenty-four hours the differences between the mean levels of radioactivity obtained in the control group and those obtained in the group with myocardial infarction were statistically highly significant (p < 0.0005). There was little overlap and a high degree of separation. An abnormal response to the test was demonstrated in every patient who had had a myocardial infarction although many of these patients had normal serum levels of cholesterol, lipid phosphorus, and alpha and beta lipoproteins. There was no significant relationship between test values and age or weight among the control group or among the group with myocardial infarction. Ten patients with abnormalities such as hypercholesteremia, marked obesity and intermittent claudication were also studied and the data are presented. The clinical significance and possible applications of this test are discussed.