Fetuin-A as a potential biomarker of metabolic variability following 60 days of head-down-tilt bed rest

Abstract

Physical inactivity and exposure to microgravity can cause a pronounced reduction in whole-body insulin sensitivity, which is influenced by the secretion of proteins from tissues of metabolic importance. Fetuin-A, a novel liver-derived protein, or hepatokine, induces insulin resistance by attenuating insulin signalling. However, it is unknown whether head-down-tilt (HDT) best, the ground based analogue of microgravity, alters the circulating concentration of fetuin-A and if changes to this biomarker impacts whole-body insulin sensitivity under these conditions.