16.4 Diabetes and its control

• Diabetes is a metabolic disorder caused by an inability to control blood glucose concentration due to a lack of the hormone insulin (Type 1) or a loss of responsiveness to insulin (Type 2).
• There are two main types of diabetes : Type 1 (insulin dependent) and Type 2 (insulin independent).
• Type 1 (insulin dependent) diabetes is a result of the body being unable to produce insulin. It typically begins in childhood, and may be the result of an autoimmune response whereby the body's immune system attacks its own cells (in this case, the beta cells of the islets of Langerhans). Type 1 diabetes develops fairly quickly, over a few weeks, with fairly obvious symptoms.
• Type 2 (insulin indepedent) diabetes is usually caused by a loss of glycoprotein receptors on body cells, or a loss of responsiveness of these receptors to insulin. However, it can also be caused by an inadequate supply of insulin from the pancreas. It usually develops in people over 40 years of age, however obesity and poor diet can also cause Type 2 diabetes in adolescence. It develops slowly, and symptoms can go unnoticed for a long time.
• Type 1 diabetes can be controlled using 2-4 injections of insulin per day. This cannot be taken orally because it is a protein, so would be digested in the alimentary canal.
• The dose of insulin injected for Type 1 diabetes treatment must be matched exactly to the person's glucose intake. If too much insulin is taken, this can cause dangerously low blood glucose concentration (resulting in unconsciousness).
• To ensure that the correct dose of insulin is administered in the treatment of Type 1 diabetes, blood glucose concentration is measured by biosensors.
• Type 1 diabetes can also be managed by regulating intake of carbohydrates.
• Type 2 diabetes is usually controlled by regulating the intake of carbohydrate in the diet and matching this to the amount of exercise performed. This can also be supplemented by insulin injections, or by the use of drugs that stimulate insulin production. Other drugs can slow down the rate at which the body absorbs glucose from the intestine.