Dr. Scott M. Grundy, director of the Center for Human Nutrition, was honored at the American Heart Association's 63rd Scientific sessions with an invitation to give the George Lyman Duff Memorial Lecture. Considered the most prestigious honor given by the Council on Arteriosclerosis of the American Heart Association to one of its members, the George Lyman Duff Memorial Lecture was established in 1956 by the Society for the Study of Arteriosclerosis in memory of Dr. Duff, a founding member and past president of the society. Dr. Duff was one of Canada's most distinguished pathologists and medical educators.

Dr. Grundy was asked to give the lecture because of his outstanding achievement in the field of arteriosclerosis. Dr. Joseph L. Goldstein, UT Southwestern's chairman of the Department of Molecular Genetics, and Dr. Michael S. Brown, UT Southwestern's director of the Center for Genetic Diseases, delivered the same lecture in 1981. Dr. Grundy spoke on the causes of high blood cholesterol in the American public. Much of the research work cited in his lecture was carried out in the Center for Human Nutrition and supported by a National Institutes of Health MERIT award and by the Friends of the Center for Human Nutrition. In his lecture, Dr. Grundy pointed out that 40 percent of American adults have moderately high cholesterol (200 to 240 milligrams per deciliter) and another 25 percent have distinctly elevated cholesterol (more than 240 mg/dL).

Four factors have been discovered, he said, that produce moderately high cholesterol. The nutrition center has been developing new approaches to control three of these factors, all of which are dietary--too much saturated fat intake, too much dietary cholesterol consumption and excess body weight. The fourth cause, Dr. Grundy said, it an unexplained rise of cholesterol with age.

Even higher cholesterol levels can be caused by genetic abnormalities, he said. Some patients have a deficiency of low-density lipoprotein (LDL) receptors, as shown by Drs. Goldstein and Brown in their Nobel prize-winning research. Other patients have an abnormality in the B protein of LDL, which Dr. Grundy and Dr. Gloria Lena Vega, associate professor of clinical nutrition, discovered.

Dr. Grundy said some patients with high cholesterol make too much LDL genetically. The discovery of all these genetic causes of high blood cholesterol should lead to new treatment approaches, he said, and the nutrition center is developing diagnostic tests for these different conditions.