Clock genes, pancreatic function, and diabetes

•Disruption of circadian rhythms is associated with glucose intolerance and diabetes.•The endocrine pancreas has an intrinsic self-sustained clock.•Clock genes play important roles in the pancreatic β cell function.•Alterations in pancreatic clock gene expression impair insulin secretion.

Circadian physiology is responsible for the temporal regulation of metabolism to optimize energy homeostasis throughout the day. Disturbances in the light/dark cycle, sleep/wake schedule, or feeding/activity behavior can affect the circadian function of the clocks located in the brain and peripheral tissues. These alterations have been associated with impaired glucose tolerance and type 2 diabetes. Animal models with molecular manipulation of clock genes and genetic studies in humans also support these links. It has been demonstrated that the endocrine pancreas has an intrinsic self-sustained clock, and recent studies have revealed an important role of clock genes in pancreatic β cells, glucose homeostasis, and diabetes.