Keeping a 'watch-full' eye on metabolic disease

Evaluation of: Coomans CP, van den Berg SA, Houben T et al. Detrimental effects of constant light exposure and high-fat diet on circadian energy metabolism and insulin sensitivity. FASEB J. 27(4), 1721-1732 (2013). The synergy of metabolic homeostasis and biological clock function is at the forefront of chronobiology research. We now have a broad appreciation of the role that the molecular clock plays in glucose homeostasis, fat metabolism, oxidative stress and metabolic sensing. Furthermore, it is clear that environmental circadian disruption, as occurs during shiftwork, can have significant negative impacts on metabolism. The implication is that misalignment among central and peripheral oscillators facilitates the appearance of metabolic disease. Coomans and colleagues provide additional insight into the link between circadian disruption and metabolic disease. They have determined that brief exposure to constant light, a paradigm known to alter central clock function, disrupts circadian rhythms of insulin sensitivity and energy metabolism and increases bodyweight. Besides the basic implications for central clock control of glucose homeostasis, their data reveal that reduced output of the pacemaker may have implications for metabolic health in the aged.