Diabetes mellitus – Symptoms, Complication, Pathology of Type 1 and Type 2, Animation

August 14, 2019 0 By Bertrand Dibbert


Diabetes mellitus refers to a group of conditions
characterized by high levels of blood glucose, commonly referred to as blood sugar. During digestion, carbohydrates in food are
broken down into glucose which is carried by the bloodstream to various organs of the
body. Glucose is taken up by the cells and is either
consumed as an energy source or stored for later use. Insulin is a hormone produced by beta cells
of the pancreas and is necessary for driving glucose into cells. Binding of insulin to its receptor on target
cells triggers a signaling cascade that brings glucose transporters to the cell membrane. When insulin is deficient, glucose cannot
enter the cells; it stays in the blood, causing high blood sugar levels while the cells are
deprived of nutrition. This results in unexplained weight loss and
increased hunger. As blood sugar level exceeds the ability of
the kidneys to reabsorb, it overflows into urine, taking water along with it, resulting
in large volumes of urine, dehydration and excessive thirst. In the long run, too much sugar in the blood
may cause damages to blood vessels, resulting in increased risks of cardiovascular diseases
such as heart attack and stroke. Damaged vessels in the eyes may lead to loss
of vision; while in the kidneys, renal failure may result. High blood sugar is also toxic to the nerves,
resulting in numbness, tingling and reduced pain perception. This, together with impaired wound healing
can lead to development of skin ulcers, most commonly in the feet. Acute hyperglycemic crises may develop when
diabetic patients undergo additional stress such as infections, other illness or inadequate
treatment. These complications involve severe disturbances
of blood homeostasis and are potentially life-threatening. There are two major types of diabetes mellitus. In type 1, beta cells of the pancreas are
destroyed by the body’s own immune system by mistake. The exact mechanism remains unclear, but genetic
factors are believed to play a major role, with at least 50 genes involved in predisposition
to the disease. Insulin production is reduced; less insulin
binds to its receptor on target cells; less glucose is taken into the cells; more glucose
stays in the blood. Type 1 is characterized by early onset, symptoms
usually start suddenly, before the age of 20. Type 1 diabetes is “insulin dependent”
and can be successfully managed with insulin replacement. In type 2 diabetes, the pancreas produces
enough insulin but something goes wrong either with receptor binding or the signaling cascade
in the target cells. The cells are not responsive to insulin and
therefore cannot import glucose. Type 2 diabetics are said to be “insulin
resistant”. Here again, genetic factors predispose susceptibility
to the disease, but lifestyle plays a major role. Type 2 is characterized by adult onset; symptoms
appear gradually, usually after the age of 30. Management focuses on weight loss and includes
a low-carb diet.