How Insulin and Glucagon Work
Functions of insulin and glucagon and what can happen if they cannot function properly.
NOV 11, 2016
Written by Susan York Morris
Insulin and glucagon are hormones that help regulate the levels of blood glucose, or sugar, in your body. Glucose, which comes from the food you eat, moves through your bloodstream to help fuel your body.Insulin and glucagon work together to balance your blood sugar levels, keeping them in the narrow range that your body requires. These hormones are like the yin and yang of blood glucose maintenance. Read on to learn more about how they function and what can happen when they don’t work well.
Insulin and glucagon work in what’s called a negative feedback loop. During this process, one event triggers another, which triggers another, and so on, to keep your blood sugar levels balanced. During digestion, foods that contain carbohydrates are converted into glucose. Most of this glucose is sent into your bloodstream, causing a rise in blood glucose levels. This increase in blood glucose signals your pancreas to produce insulin.
The insulin tells cells throughout your body to take in glucose from your bloodstream. As the glucose moves into your cells, your blood glucose levels go down. Some cells use the glucose as energy. Other cells, such as in your liver and muscles, store any excess glucose as a substance called glycogen. Your body uses glycogen for fuel between meals.
Glucagon works to counterbalance the actions of insulin. About four to six hours after you eat, the glucose levels in your blood decrease, triggering your pancreas to produce glucagon. This hormone signals your liver and muscle cells to change the stored glycogen back into glucose. These cells then release the glucose into your bloodstream so your other cells can use it for energy. This whole feedback loop with insulin and glucagon is constantly in motion. It keeps your blood sugar levels from dipping too low, ensuring that your body has a steady supply of energy.
Your body’s regulation of blood glucose is an amazing metabolic feat. However, for some people, the process doesn’t work properly. Diabetes mellitus is the best known condition that causes problems with blood sugar balance.Diabetes refers to a group of diseases. If you have diabetes or prediabetes, your body’s use or production of insulin and glucagon are off. And when the system is thrown out of balance, it can lead to dangerous levels of glucose in your blood.
Of the two main types of diabetes, type 1 diabetes is the less common form. It’s thought to be an autoimmune disorder in which your immune system destroys the cells that make insulin in your pancreas. If you have type 1 diabetes, your pancreas doesn’t produce insulin. As a result, you must take insulin every day. If you don’t, you’ll get very sick or you could die. For more information, read about the complications of type 1 diabetes.
With type 2 diabetes, your body makes insulin but your cells don’t respond to it normally. They don’t take in glucose from your bloodstream as well as they once did, which leads to higher blood sugar levels. Over time, type 2 diabetes makes your body produce less insulin, which further raises your blood sugar levels. Some women develop gestational diabetes late in their pregnancies. In gestational diabetes, pregnancy-related hormones may interfere with how insulin works. This condition normally disappears after the pregnancy ends. However, if you’ve had gestational diabetes, you’re at greater risk of developing type 2 diabetes in the future.
If you have prediabetes, your body makes insulin but doesn’t use it properly. As a result, your blood glucose levels are raised, though not as high as they would be if you had type 2 diabetes. Many people who have prediabetes go on to develop type 2 diabetes.