Blood sugar, insulin and HbA1c
Insulin and glucagon are hormones that help regulate the blood sugar (glucose) levels in your body. Find out how they work together. Insulin is an essential hormone produced by the pancreas. Its main role is to control glucose levels in our bodies. The science behind type 2 diabetes including the role of insulin, the effects of high and low blood sugar and ideal HbA1C ranges.
Regulation The pancreas releases insulin and glucagon shown here in purple and green to control blood sugar levels. Blood sugar levels are a measure of how effectively an individual's body uses glucose. When the body does not convert enough glucose for use, blood sugar levels remain high.
How Insulin and Glucagon Work
Insulin helps the body's cells absorb glucose, lowering blood sugar and providing the cells with the glucose they need for energy. When blood sugar levels are too low, the pancreas releases glucagon. Glucagon forces the liver to release stored glucose, which causes the blood sugar to rise. Insulin and glucagon are both released by islet cells in the pancreas. These cells are clustered throughout the pancreas.
Beta islet cells B cells release insulin, and alpha islet cells A cells release glucagon. How insulin works The body converts energy from carbohydrates into glucose. The body's cells need glucose for energy, but most cells cannot directly use glucose.
Diabetes treatment: Using insulin to manage blood sugar - Mayo Clinic
Insulin acts like a key to allow glucose to access the cells. It attaches to insulin receptors on cells throughout the body, telling those cells to open up and allow glucose to enter. Low levels of insulin are constantly circulating throughout the body. When insulin rises, this signals to the liver that blood glucose is also high. The liver absorbs glucose, then changes it to a storage molecule called glycogen. When blood sugar levels drop, glucagon signals the liver to convert the glycogen back to glucose.
This makes blood sugar levels go up. Insulin also supports healing after an injury by delivering amino acids to the muscles. Amino acids help build the protein found in muscle tissue, so when insulin levels are low, muscles may not heal properly.
How glucagon works The liver must store glucose to power the cells during times of low blood sugar. Skipping meals and poor nutrition can lower blood sugar. By storing glucose, the liver makes sure blood glucose levels stay steady between meals or during sleep. When blood glucose falls, cells in the pancreas secrete glucagon. What happens if I have too much insulin? If a person accidentally injects more insulin than required, e. This leads to abnormally low blood glucose levels called hypoglycaemia.
The body reacts to hypoglycaemia by releasing stored glucose from the liver in an attempt to bring the levels back to normal. Low glucose levels in the blood can make a person feel ill.
The body mounts an initial 'fight back' response to hypoglycaemia through a specialised set of of nerves called the sympathetic nervous system. This causes palpitations, sweating, hunger, anxiety, tremor and pale complexion that usually warn the person about the low blood glucose level so this can be treated. However, if the initial blood glucose level is too low or if it is not treated promptly and continues to drop, the brain will be affected too because it depends almost entirely on glucose as a source of energy to function properly.
This can cause dizziness, confusion, fits and even coma in severe cases. Some drugs used for people with type 2 diabetesincluding sulphonylureas e. The body responds in the same way as if excess insulin has been given by injection. Furthermore, there is a rare tumour called an insulinoma that occurs with an incidence of per million population. It is a tumour of the beta cells in the pancreas.
Patients with this type of tumour present with symptoms of hypoglycaemia. What happens if I have too little insulin? People with diabetes have problems either making insulin, how that insulin works or both. The main two types of diabetes are type 1 and type 2 diabetes, although there are other more uncommon types.
People with type 1 diabetes produce very little or no insulin at all. This condition is caused when the beta cells that make insulin have been destroyed by antibodies these are usually substances released by the body to fight against infectionshence they are unable to produce insulin.
With too little insulin, the body can no longer move glucose from the blood into the cells, causing high blood glucose levels. If the glucose level is high enough, excess glucose spills into the urine. This drags extra water into the urine causing more frequent urination and thirst.
This leads to dehydrationwhich can cause confusion. In addition, with too little insulin, the cells cannot take in glucose for energy and other sources of energy such as fat and muscle are needed to provide this energy. This makes the body tired and can cause weight loss. If this continues, patients can become very ill.
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This is because the body attempts to make new energy from fat and causes acids to be produced as waste products. Ultimately, this can lead to coma and death if medical attention is not sought.