Effect of a fatty meal on whole blood and plasma viscosity

¹ Department of Nutrition and Food Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, Division of Pathology, Institute of Nutrition of Central America and Panama (INCAP), Guatemala, C. A., and Medical Research Department, Beth Israel Hospital and Harvard Medical School, Boston, Massachusetts

The viscosity of whole blood of 40 medical students measured with a Brookfield cone and plate viscometer showed no change before and after a fatty meal although the serum lipids increased. In separate experiments, no change was noted in plasma viscosity as determined by the capillary tube technique although plasma lipids increased. From theoretical considerations, it was suggested that methods of determining viscosity within a 2% error would be necessary in order to detect changes in plasma and whole blood viscosity after a fatty meal. However, even with the GDM low-shear rate coaxial viscometer, which has an accuracy reputed to be 2%, no change was observed in the whole blood or plasma viscosity. The results with the GDM viscometer compared favorably with the results from the Brookfield cone and plate viscometer. In 2 out of 52 cases a definite decrease in whole blood viscosity was found 3 hr after a fatty meal. The plasma viscosities, however, did not change. It is postulated that in rare cases a decrease in the yield stress of the cell aggregates due to the increased lipids results in a decreased blood viscosity. The mechanics by which this occurred is under study.

Submitted on June 15, 1963