Insulin resistance and tissue repair: a "fato-logical" phenomenon

PathophysiologyType 2 diabetes mellitus (T2DM ) is a chronic metabolic disorder characterized by insulin resistance and progressive pancreatic β-cell dysfunction, leading to impaired glucose homeostasis. It results from interactions among genetic predisposition, environmental factors, and metabolic stressors, such as overnutrition and a sedentary lifestyle.Insulin Resistance and Glucose DysregulationEarly T2DM involves insulin resistance in skeletal muscle, adipose tissue, and the liver.

Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...

After cellular or tissue damage, the resident stem cells present in the human body can locally repair and regenerate the damaged tissue or organ. However, even though some tissues do not have stem cells, they can repair and regenerate with the help of pre-existing cells. For example, beta cells of the pancreas and hepatocytes of the liver can divide to renew and regenerate the tissue. Here, both cell division and cell death are well regulated by homeostasis.
However, failure of such a system...

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by insulin resistance, in which target tissues such as the liver, muscle, and adipose tissue respond poorly to insulin. It is also associated with inadequate compensatory insulin secretion, where pancreatic β-cells fail to produce sufficient insulin. Together, these abnormalities lead to persistent hyperglycemia.EtiologyT2DM develops through a complex interaction of genetic predisposition and environmental or...

Type 1 diabetes mellitus arises from an immune-mediated destruction of pancreatic β-cells, resulting in an absolute deficiency of insulin. This process develops in genetically susceptible individuals when autoimmunity, environmental exposures, and immunologic dysregulation converge to trigger a targeted attack on the insulin-producing cells of the pancreas. The β-cells are located within the islets of Langerhans and are essential for regulating blood glucose by facilitating cellular uptake of...

Carbohydrates are polymers composed of molecules containing atoms of carbon, hydrogen and oxygen. One gram of carbohydrate can provide four kilo-calories of energy, which makes it the most efficient instant energy source.
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...