Thiamin deficiency impairs endotoxin-induced increases in hepatic glucose output

Abstract

We addressed the role of thiamin, a cofactor for several enzymes involved in glucose metabolism, in the glucose metabolic response to endotoxin. Characterized by hyperglycemia, increased hepatic glucose production exceeding elevated rates of whole-body glucose utilization, this response is mediated by hormones and cytokines and is dependent on the immune and nutritional status of the host. We hypothesized that a thiamin-deficient state would impair the metabolic response to endotoxin. Rats were fed a thiamin-deficient or control diet for 6 wk before in vivo assessment of glucose kinetics. In control rats, Escherichia coli endotoxin increased the rate of glucose appearance (+76%), disappearance (+70%), and metabolic clearance (+50%). Thiamin deficiency resulted in increased plasma glucose (18%) and lactate (3- to 4-fold) as well as in a 30% decrease in insulin and an increase in glucagon (2.6-fold) and corticosterone (3.6-fold). Thiamin deficiency inhibited the endotoxin-induced hyperglycemia and the rise in hepatic glucose production, glucose utilization, and metabolic clearance rate.