American Journal of Clinical Nutrition, Vol 24, 859-863, Copyright © 1971 by The American Society for Clinical Nutrition, Inc.

Neutropenia in prolonged fasting

¹ From the Veterans Administration Center, Los Angeles, California, and the University of California, Los Angeles

The nature of the fasting neutropenia in obese subjects was studied. Neutrophil counts rose in more than half the patients during the first 10 fast days and decreased in the others. Subsequently, the decrease was general, falling to 50% of base-line figures. The administration of folate throughout fasting resulted in a slight delay in the development of neutropenia and had no influence if instituted during the second month of fasting. Hypocaloric refeeding, after 55 days of fasting, was associated with slight and temporary improvement in the neutropenia, which was independent of folate administration. Average neutrophil nuclear lobe counts did not change either during the fasting period or during a period of hypocaloric refeeding. The neutropenia developed concurrently with a drastic fall in plasma volume, which suggests that intravascular redistribution of the neutrophils may account for the neutropenia. In addition, it is possible that protein depletion may, in the later phases of fasting, impair bone marrow activity. Under the stimulus of acute infection, the number of neutrophils increases regardless of the duration of the preceding fast.