The etiology (cause) of diabetes is not confirmed. Although it appears that diabetes may be genetic, environmental factors also may contribute to its occurrence. For example, viruses or obesity may precipitate the disease in people who have a genetic predisposition.
The World Health Organization indicates that the prevalence of the disease is increasing worldwide, especially in areas showing improvement in living standards.
The abnormal concentration of glucose in the blood of diabetic clients draws water from the cells to the blood. When hyperglycemia exceeds the renalthreshold, the glucose is excreted in the urine (glycosuria). With the loss ofthe cellular fluid, the client experiences polyuria (excessive urination), and polydipsia (excessive thirst) typically results.
The inability to metabolize glucose causes the body to break down its own tissue for protein and fat. This response causes polyphagia (excessive appe-tite), but at the same time a loss of weight, weakness, and fatigue occur. The body’s use of protein from its own tissue causes it to excrete nitrogen.
Because the untreated diabetic client cannot use carbohydrates for energy, excessive amounts of fats are broken down, and consequently the liver produces ketones from the fatty acids. In healthy people, ketones aresubsequently broken down to carbon dioxide and water, yielding energy. In diabetic clients, fats break down faster than the body can handle them. Ketones collect in the blood (ketonemia) and must be excreted in the urine (ketonuria). Ketones are acids that lower blood pH, causing acidosis. Acidosis can lead to diabetic coma, which can result in death if the client is not treated quickly with fluids and insulin.
In addition to the symptoms previously mentioned, diabetic clients suffer from diseases of the vascular system. Atherosclerosis (a condition in which there is a heavy buildup of fatty substances inside artery walls, reducing blood flow) is a major cause of death among diabetic clients. Damage to the small blood vessels can cause retinal degeneration. Retinopathy is the leading cause of blindness in the United States. Nerve damage (neuropathy) is not uncommon, and infections, particularly of the urinary tract, are frequent problems.