Grizzly Bears Exhibit Augmented Insulin Sensitivity while Obese Prior to a Reversible Insulin Resistance during Hibernation.

Exploring potential models of diabetes and obesity, Nelson et al. show that grizzly bears exhibit three distinct seasonal periods of insulin responsiveness dissociated from obesity: insulin sensitivity in the lean state during spring, augmented responsiveness while obese in autumn, and insulin resistance during hibernation. Insulin responsiveness is mediated by AKT/PTEN signaling, independent of circulating insulin levels. [ABSTRACT FROM AUTHOR]