The role of circadian clocks in metabolism

Abstract

Not long ago, the mysteries of the human body were unraveled by identification of biological rhythm. The fact that organisms try to maintain homeostasis of regular rhythm of the day by adapting to daily fluctuations of environmental changes or stresses is well-known. Physiologic responses to extrinsic stimuli from environment as well as intrinsic timekeeping clock generate an organism's biological rhythm. Substantial evidence has revealed that disruption of fine-tuned circadian rhythm contributes to numerous pathologies including the metabolic syndrome. Therefore, understanding the circadian rhythms and the impact of its dyssynchrony on metabolic disorders especially related to insulin resistance are necessary for the treatment of circadian rhythm-related disorders. This review will focus on components of the circadian clock and their roles in adaptation to and anticipation of daily metabolic fluctuation. Furthermore, the pathophysiology of metabolic syndrome affected by the failure of circadian clocks will be discussed.