Role of insulin in glucose homeostasis

Let’s take a look at what’s going on at the cellular level. Even at high blood levels, very little glucose enters the cell. For this, the cell needs insulin. The higher the level of glucose, the more insulin goes into production to balance sugar levels in the blood.
Insulin binds to its target cell through insulin receptors, this triggers a cascade of reactions that causes the cell to include glucose transport proteins into its membrane. Now glucose molecules enter the cell through transport proteins.
Thus, insulin enables the insulin-dependent uptake of glucose into these tissues and hence lowers blood glucose levels by removing the exogenous glucose from the bloodstream. This in turn reduces the production of insulin by the pancreas. When blood levels of insulin decrease and insulin receptors are no longer occupied, the glucose transporters are recycled back into the cell.
In a healthy individual, insulin production and release is a tightly regulated process, allowing the body to balance its metabolic needs.

However, in diabetes mellitus, the process of glucose utilization is disrupted, leading to its increase in blood level – this condition is called hyperglycemia. Diabetes mellitus (DM) occurs either due to a lack of insulin (DM type 1) – when the immune system attacks and destroys the cells in which it is produced, or due to a violation of the action of insulin (DM type 2) – when the cells do not respond to insulin as they should normally. Due to the lack of insulin, glucose does not enter the cells, and its high level in the blood for a long time is dangerous, because it causes vascular lesions, leading to cardiovascular diseases, atherosclerosis, and stroke, it damages the nervous tissue, kidneys, and eyes. Understanding the mechanisms of insulin action is therefore essential for the continued development of effective therapeutic strategies to combat DM.

More details:

Prediabetes and measures of prophylaxis

Differences between type 1 and type 2 diabetes

Causes, mechanisms of the disease development and symptoms (Diabetes mellitus type 1)

Causes, mechanisms of the disease development and symptoms (Diabetes mellitus type 2)