Glucagon : Risk of Hypoglycemia in Type 1 Diabetes
By Swati Mishra, Ph.D.
4 minutes read
So now we know what is insulin, its role and significance in type 1 diabetes (T1D) –Today’s blog post is about another very important metabolic hormone called “Glucagon” which works in tandem with insulin in regulating blood glucose levels and maintains the concentration in the tight range.
People with T1D are absolute insulin deficient and are mostly put on insulin replacement therapy, which requirer them to inject exogenous insulin (exogenous insulin is any insulin that is not produced by the body and comes from outside) multiple times a day via syringe, inhalation device, insulin pump, insulin pen or insulin jet injector, in order to keep their blood glucose in check. In normal healthy people, the insulin-producing beta cells maintain a “perfect natural balance” between amount of glucose produced based on our food intake and insulin. Which means, whether we eat Wendy’s 940 calories Beaconator Burger or a 660 calories Taco Salad, pancreas puts out the exact amount of insulin needed to turn the glucose into energy. Since people with T1D cannot produce their own insulin and rely on external insulin, which is injected manually into the blood stream to metabolize glucose, they lose their ability to tightly maintain the perfect glucose-insulin balance. Therefore, sometimes too much insulin or not eating enough carbohydrates, results into blood-glucose levels lower than that required for normal functioning [healthy range is 90–130 milligrams per deciliter (mg/dL)]. This condition is called Hypoglycemia. In non-diabetic individuals, on the event of hypoglycemia (too much exercise, carbohydrate deficient diet, starving, fasting, sickness etc), “glucagon” takes matter into its hands. Unlike insulin, glucagon is produced by alpha cells in the pancreas in response to the below normal glucose levels. Glucagon works against insulin; it directs our liver to produce glucose from stored glycogen to replenish low glucose levels. At the same time it activates the synthesis of glucose from amino acids that are derived from proteins in our diet and accelerates break down of stored fats into fatty acids that can be used by cells as a fuel.
In people with T1D, the beta cells are damaged, but the alpha cells are still there to produce glucagon. However, in most of the type-1-diabetics, due to all time high levels of circulating insulin, the alpha cells are no more signal responsive – which means hypoglycemia does not stimulate glucagon production. This makes the matter worse, and make type-1-diabetics prone to severe hypoglycemia. Common symptoms associated with hypoglycemia are: sweating, fatigue, dizziness, hunger, and weakness. Severe symptoms include: heart rate higher than usual, blurred-vision, confusion, convulsions (a sudden, violent, irregular movement of a limb or of the body, caused by involuntary contraction of muscles), loss of consciousness and coma.
Connect with me on Linkedin, Facebook and Follow me on Twitter
Wegovy and Ozempic are not just in the drugstore: alpha cells are allies and make them on their own
Alpha cells represent ~30–40% of the endocrine cells in the human islet and are the “emergency brake” against hypoglycemia: when blood glucose levels drop, they release glucagon, which stimulates hepatic glucose production. Glucagon release is driven by metabolic signals (ionic channels) paracrine inputs (insulin and somatostatin inhibit it; mediators released by alpha- and beta-cells can…
