What is Insulin and how does it work?

Insulin in Diabetes

It is common for people with type 1 diabetes to take insulin injections as their body no longer produces insulin. They are asked to take specific dosages of insulin prior to their meals in order to provide glucose to every cell of the body. Though it is used by people with type 1 diabetes, it might be necessary for people with type 2 diabetes also.

What is insulin?

Insulin is a hormone produced by the pancreas, an endocrine gland. It is a peptide hormone that is produced in the beta cells of pancreas. Insulin is secreted by the pancreas when it receives external stimuli. It helps in carbohydrate metabolism.

Functions of Insulin

Insulin not only helps regulate blood sugar levels in the body, it is also essential for many other functions.

  • Insulin acts as the key that opens up the cells of muscles and tissues of the body to absorb glucose. If there is resistance from the muscles and tissues to the insulin, it leads to insulin resistance. If there isn’t enough insulin, it leads to lack of absorption of glucose. Both conditions lead to high blood sugar levels.
  • Insulin is vital for many metabolic processes in the body. When blood sugar levels increase in the body (generally after a meal), insulin encourages the storage of glucose in the liver in the form of glycogen.
  • Insulin modifies the activity of many enzymes in the body.
  • As a growth factor, insulin helps in muscle buildup, replication of DNA, and synthesis of protein.
  • It manages the breakdown of fat cells into lipoproteins and triglycerides.
  • It assists in brain function and is known to improve memory.
  • It regulates the volume of urine and the excretion of sodium from the body.

How does Insulin work?

Once you consume food, glucose levels in your blood rises. This rise in glucose level triggers the pancreas to secrete insulin. However, secretion of insulin is not just dependent on the food consumed. Some internal factors such as hormonal imbalances can either increase or decrease the amount of insulin secreted.

Once insulin is released, it binds itself with glucose in blood and sends messages to the cells and tissues of the body to absorb the glucose present in the bloodstream. Interaction between insulin and insulin receptors present in the cells is very important for the maintenance of normal blood sugar levels.

When cells of the body and its insulin receptors do not respond to the insulin, it leads to a condition called insulin resistance. Insulin resistance then leads to diabetes. In some cases, due to autoimmune diseases, the cells of the body destroy beta cells of the pancreas where insulin is produced. This leads to type 1 diabetes.

While a reduction in insulin or lack of response to insulin leads to diabetes, hyperinsulinemia is a condition in which the levels of insulin are high. This condition is caused due to other diseases like pancreatic cancer, polycystic ovarian disease, excess consumption of trans fats, and obesity.

Types of insulin

  • Rapid-acting insulin: This is usually taken before consumption of foods.
  • Short-acting insulin: This insulin is used along with long-acting insulin and taken to reduce postprandial blood sugar levels.
  • Intermediate-acting insulin: This insulin is taken in combination with rapid-acting and short-acting insulin twice a day.
  • Long-acting insulin: This type of insulin is taken in combination with rapid-acting and short-acting insulin twice a day.

Insulin for Type 2 Diabetes

For people with advanced duration of type 2 diabetes, and for people with uncontrolled diabetes, insulin therapy is advised. This is done when oral medications are ineffective in controlling postprandial blood sugar levels.

Many people who age with diabetes ultimately have progressive pancreatic dysfunction. This leads to insufficient production of insulin. Apart from that, as the duration of diabetes increases, the chances of diabetes complications also increases. In cases of diabetic nephropathy and other complications, insulin therapy is preferred in order to stabilize HbA1c.