Building Competency in Diabetes Education THE ESSENTIALS

PATHOPHYSIOLOGY| 3-9

Educators need to understand counterregulatory responses in order to facilitate discussion of adaptive stress responses, including prevention, recognition and management of hypoglycemia with individuals living with diabetes.

Glucagon Glucagon is a hormone that increases the amount of glucose or fuel available in the blood. In the fasting state, glucagon is the primary regulator of the following processes (4,6–8,10): • Breakdown and release of stored glycogen in muscle and liver tissue. During the first eight to 12 hours of fasting, glucose is released from the liver through the breakdown of glycogen into glucose. • Release of amino acids from muscle tissue, which are used by the liver as a substrate in making glucose (gluconeogenesis). After eight to 12 hours of fasting, gluconeogenesis will occur to produce glucose from amino acids, glycerol and lactate. • A small effect on the release of FFAs and glycerol from fat tissue. FFAs are used as fuel by muscle tissue. Glycerol is used by the liver as a substrate in making glucose. • Conversion of FFAs into ketone bodies (beta-hydroxybutyrate and acetoacetate) after prolonged starvation (6). Catecholamines (12) Epinephrine and norepinephrine mobilize glycogen stores, decrease glucose uptake by the liver and inhibit insulin production. Catecholamines act on the liver to increase hepatic glycogenolysis and gluconeogenesis. Growth hormone (12) Growth hormone antagonizes the insulin effect and decreases glucose uptake in the adipose tissue. It increases glucose production through gluconeogenesis and glycogenolysis from the liver and kidney. Also, growth hormone stimulates lipolysis which results in an increase in FFAs. As a result of glucose homeostasis in healthy individuals, plasma glucose and insulin concentration remain remarkably flat overnight with modest increase in insulin secretion just before dawn to limit hepatic glucose production and prevent fasting hyperglycemia. Dawn phenomenon describes spontaneous rise in blood glucose and/or insulin requirements close