 The net effect is an increase in the concentration of glucose in the blood, further complemented by a decrease in the sensitivity of peripheral tissue to insulin, thus preventing this tissue from taking the glucose from the blood.Last, cortisol has a permissive effect on the actions of hormones that increase glucose production, such as glucagon and adrenaline.Cortisol also plays an important, but indirect, role in liver and muscle glycogenolysis, the breaking down of glycogen to glucose-1-phosphate and glucose - this results from the effects on glucagon action, described above.