Insulin resistance is the main cause of diabetes type 2 and obesity.
To understand what is insulin resistance you must know a few important terms frequently used.
Insulin is a hormone produced in the pancreas. This hormone allows the glucose in the blood stream to enter into the cells. Using the famous door-key theory, body cells have doors that are only opened by insulin in order to get glucose in to be used to produce energy, to be stored in case of need and converted as fat when not needed for any of the previous two processes.
Why and when can insulin levels increase?
Insulin is always present in the blood stream in order to manage the glucose levels. In the presence of insulin resistance there are different problems occurring:
Hyperglycaemia due to glucose consumption
Extra glucose uptake by the liver
When carbohydrates – such as sugar and starchy food – are eaten they are broken down into glucose. Eventually it travels in the blood stream and get into the cells. As explained before, the insulin is responsible for bringing the glucose into the cells. At meal times, because levels of glucose are higher, the pancreas releases more insulin into the blood stream in order to provide an effective response to assist this big amount of glucose that was consumed and try to keep a normal blood glucose concentration.
Following this rationale, insulin resistance will block the action of insulin – allowing glucose coming into the cells. As a result, glucose will increase in the blood stream, causing raised levels of blood glucose, also known as hyperglycaemia. Hyperglycaemia is aggravated by the liver which is also affected by insulin resistance.
For more info about the liver and hyperglycaemia, read here.
The problematic cicle
Because blood glucose is raised in the blood stream, the pancreas receives a signal to release more insulin as a response of this glucose demand. Due to high insulin levels there is a miscommunication between the insulin, the fat cells in the liver and the fat in the adipose tissue.
In one hand the liver continues to synthesize and store fat, which results in the build-up of triglyceride in the liver. On the other hand, when the insulin level is higher, such as after a meal, the insulin stops the process of fat breakdown. In an insulin resistance condition, however, the breakdown process is not turned off, increasing the visceral fat and causing weight gain if continuously.
More insulin – more fat (inside the cells/liver and adipose tissue) – the more the pancreas is working in order to produce even more insulin to cover the glucose. This cycle can lead to Diabetes type 2, progress ongoing diabetes type 2 and obesity.
At some point the pancreas won’t be able to give response to this high demand of insulin. Here is the point where diabetes will progress and the need of compensate the pancreas malfunction with medication. The pancreas stops producing enough insulin but the body still needs it.
Insulin resistance can be present in either obese individuals and individuals with diabetes. Not all people with obesity and insulin resistance have diabetes type 2.
So what can cause insulin resistance in the first place?
Insulin resistance is a very complex process and hard to explain or understand what comes first in the process. I would say that there is a group of conditions that will develop and increase the insulin resistance.
Bear in mind that insulin resistance is intimate connected with lifestyle. A healthy diet and regular physical activity also have an important role, not only for people with diabetes but for everyone.