The insulin is a hormone which is being produced in the pancreas and secreted into the blood stream when our body identifies a rise of glucose level in the blood. Although the most known role of the insulin is relate to regulating glucose levels in the blood, it has many varied roles in our body: it is also a growth factor, it encourages tissues building, it accumulates glycogen inside the cells and it encourages fat accumulation.
The glucose in the blood needs the insulin in order to pass the side of the cell, therefore a lack of insulin (caused by pancreas dysfunction) or insulin resistance will be expressed by a rise of the glucose level in the blood.