The Determination of Early Thiamine-Deficient States by Estimation of Blood Lactic and Pyruvic Acids After Glucose Administration and Exercise

Abstract

Thirty-six human subjects receiving diets of known low content of thiamine were studied from the standpoint of the relationship of the levels of lactic and pyruvic acid of the blood to the degree of thiamine deficiency. The normal relationship between blood glucose levels and those of lactic and pyruvic acid was investigated, and the necessity demonstrated for considering this relationship in evaluating levels of blood lactate and pyruvate. In the fasting state and in the absence of exercise there was no consistent rise in the levels of lactic and pyruvic acid in mild degrees of thiamine deficiency, and it would seem that the organism at rest can maintain the normal equilibrium levels of these metabolites during mild thiamine deprivation. The basal levels were elevated in some cases of more severe thiamine deficiency but, even then, only after pronounced clinical signs of pathology were apparent. The elevation of the lactate and pyruvate values of the blood which followed a combined “metabolic load” composed of ingestion of glucose and mild exercise was found to give more useful data than were obtained either after glucose ingestion alone or after exercise alone. The usefulness of the determination for CMI was demonstrated in subjects on controlled thiamine-deficient diets of different severity. The use of the method to pick out thiaminedeficient individuals from population groups was also illustrated.