How insulin & glucagon work (and what are they?)
Insulin and glucagon are hormones that help regulate the levels of blood glucose — aka sugar — in your body. Glucose comes from the food you eat and moves through your bloodstream to help fuel your body. Insulin controls whether sugar is used as energy or stored as glycogen. Glucagon signals cells to convert glycogen back into sugar, (Read on and all will be explained).
Insulin and glucagon work together to balance your blood sugar levels, keeping them in the range that your body requires.
How insulin works
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, (otherwise known as a sugar spike), which signals your pancreas to produce insulin. The insulin tells cells throughout your body to take in glucose from your bloodstream, to store for a “rainy day” and also helps to offset inflammation in the body. As the glucose moves into your cells, your blood glucose levels go down. Some cells use glucose as energy. Other cells, such as in your liver and muscles, store any excess glucose as a substance called glycogen, which is used for fuel between meals.
How glucagon works
Glucagon works to counterbalance the actions of insulin. About 4–6 hours after you eat, the glucose levels in your blood decrease. This triggers your pancreas to produce glucagon. This hormone signals your liver and muscle cells to convert 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 domino effect with insulin and glucagon is constantly in motion. It keeps your blood sugar levels from dipping too low, preventing hypoglycaemia, and ensuring that your body has a steady supply of energy.
Definitions
Glucose - sugar that travels through your blood to fuel your cells.
Insulin - a hormone that tells your cells either to take glucose from your blood for energy or to store it for later use.
Glycogen - a substance made from glucose that’s stored in your liver and muscle cells to be used later for energy.
Glucagon - a hormone that tells cells in your liver and muscles to convert glycogen into glucose and release it into your blood so your cells can use it for energy.
Pancreas - an organ in your abdomen that makes and releases insulin and glucagon.
Glucose disorders
Your body’s regulation of blood glucose is an amazing feat of nature and evolution. But for some people, the process does not work properly. Diabetes can cause 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. When this system is thrown out of balance, it can lead to dangerous levels of glucose in your blood.
Type 1 diabetes
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 does not produce insulin or does not produce enough insulin. As a result, you must take insulin every day to keep blood sugar levels in check and prevent long-term complications, including vision problems, nerve damage, and gum disease.
Type 2 diabetes
With type 2 diabetes, your body makes insulin, but your cells do not respond to it the way they should. This is known as insulin resistance. Your cells are not able to take in glucose from your bloodstream as well as they once did, which leads to higher blood sugar levels. Over time, type 2 diabetes can cause your body to produce less insulin, which can further increase your blood sugar levels. Some people can manage type 2 diabetes with diet and exercise. Others may need to take medication (like metformin or glyclazide) or insulin to manage their blood sugar levels.
Gestational diabetes
Some people develop gestational diabetes around the 24th-28th week of pregnancy. In gestational diabetes, pregnancy-related hormones may interfere with how insulin works. This condition often disappears after the pregnancy ends. However, if you’ve had gestational diabetes, you may have a greater risk of developing type 2 diabetes in the future.
Prediabetes
If you have prediabetes, your body makes insulin but does not use it properly. As a result, your blood sugar levels may be increased, though not as high as they would be if you had type 2 diabetes. Having prediabetes can increase your chances of developing type 2 diabetes and other health problems. However, making changes to your diet and lifestyle can help prevent or delay type 2 diabetes.
Talk with your GP
If you have more questions about insulin or glucagon, consider talking with a healthcare professional. In addition to helping you understand how these hormones affect blood sugar control, a NHS doctor, diabetes nurse or dietitian can also suggest diet and lifestyle changes to help balance blood sugar levels.
Questions you have might include:
What’s my current HbA1c numbers?
Is my blood glucose at a safe level?
Do I have prediabetes?
What can I do to avoid developing diabetes?
How do I know if I need to take insulin?
In summary
Insulin and glucagon are two important hormones that work together to balance blood sugar levels. Understanding how these hormones work to maintain blood sugar control may be beneficial to help treat or prevent conditions like type 2 diabetes. Your GP or registered dietitian can also recommend diet or lifestyle changes to balance hormone and blood sugar levels and support overall health.
Extracts taken from Kelly Wood, MD, & Susan York-Morris from https://www.healthline.com