Glucose utilization by sweat glands during fasting in man

Abstract

Fifteen normal subjects were fasted for 3 to 7 days while undergoing daily sweating in an environmental chamber. Sweat lactate concentration decreased 19% and reached a new steady state by the third day of fast. Recovery of 14C-labeled lactate in sweat after injection of 14C-labeled glucose was enhanced during starvation, suggesting preferential utilization of circulating glucose for sweat production during the fasted state. Sequential skin biopsies demonstrated that sweat gland glycogen content decreased markedly during sweating in fasted subjects; nearly complete recovery of normal glycogen content was observed 6 hr after conclusion of sweating. In the sweat gland, significant dependence upon carbohydrate metabolism persists during the fasted state.