Definition & Clinical Appearance
Diabetes mellitus is a metabolic disorder with abnormally high blood glucose levels (hyperglycemia) as it’s most prominent feature. During intestinal digestion carbohydrates and proteins are broken down into simple sugars and amino acid, respectively. The liver converts all of the sugars and some of the amino acids into glucose, a simple sugar that is used for energy by every cell in the body. Glucose passes from the bloodstream into the cells with the help of insulin, a hormone produces by the pancreas. By attaching to receptor sites on the surface membrane of a cell, insulin promotes the movement of glucose-transport proteins from the interior of the cell to its surface, where they bind with glucose and carry it into the cell. In diabetes mellitus, several problems may interfere with this process: pancreatic insulin production may be partially or completely impaired, or body cells may become unable to respond to normal amounts of insulin efficiently. These underlying problems in fact distinguish the two main types of the diabetes. In the more common type 2 diabetes mellitus, also known as adult-onset diabetes, insulin production by the pancreas is only moderately reduced, but cells are unable to respond efficiently to insulin – a condition referred to as insulin resistance. In both type 1 and type 2 diabetes, the hyperglycemia leads to excretion of glucose in the urine and an accompanying increase in urine production. If inadequate amounts of insulin are administered to patients with type 1 diabetes, unrestrained release of fatty acids from adipose (fat) tissue leads to the overproduction of ketone bodies in the liver. Accumulation of ketone bodies can cause a life-threatening condition known as diabetic ketoacidosis (DKA). DKA may occasionally affect those with type 2 diabetes in periods when the body is highly stressed, for example, during a severe infection. People with type 2 diabetes are susceptible to another life-threatening condition known as a hyperosmolar nonketotic state, characterised by extremely high blood sugar levels. This condition usually occurs in elderly persons with some other serious underlying illness. An episode of either DKA or the hyperosmolar state may be the first indication that someone has diabetes. People with diabetes may also suffer from low blood sugar (hypoglycemia) if too much insulin or oral hypoglycaemic agent is given for treatment. Treatment of type 1 diabetes requires between on and four daily injections of insulin. Insulin cannot be taken by mouth, since digestive juices would destroy it). In addition, diet and exercise must be planned carefully to ensure that blood glucose levels are neither too high nor too low. Type 2 diabetes may be controlled with a combination of diet, exercise, and weight loss, although medications (including insulin) are usually necessary.
Signs and Symptoms
• Excessive and frequent urination (as often as every hour or so).
• Nighttime awakening to urinate is common.
• Increased thirst.
• Increased appetite.
• Unintentional weight loss.
• Blurred vision.
• Fatigue and weakness.
• Recurring or persistent infections of the bladder, skin or gums.
• Numbness and tingling in feet and hands.
• Symptoms of hypoglycemia.
• Emergency symptoms of hyperosmolar nonketotic states: extreme thirst, lethargy, weakness, mental confusion, coma.
• Emergency symptoms of diabetic ketoacidosis: nausea and vomiting, laboured breathing, mental confusion, coma.
Aetiology
Type 1 diabetes is an autoimmune disorder, resulting from a mistaken attack by the immune system on insulin-producing cells in the pancreas. Genetic factors are important in type 2 diabetes. Contributing factors Obesity predisposes individuals to the development of type 2 diabetes. Certain drugs, such as corticosteriods or thiazide diuretics, may increase the risk of type 2 diabetes. Other disorders, such as hemochromatosis, chronic pancreatitis, Cushing’s Syndrome, or acromegaly, may lead to diabetes. Surgical removal of the pancreas may also lead to diabetes. Pregnant women may develop diabetes (gestational diabetes), which usually disappears after childbirth, these women are at an increased risk for subsequent development of type 2 diabetes. Contrary to popular belief, eating lots of foods rich in sugar does not promote diabetes.
Start of Pathology / Onset
In type 1 diabetes mellitus, also known as juvenile diabetes, the pancreas produces little or no insulin. Type 1 diabetes develops suddenly and most commonly affects those under age 30; the average age of onset is between 12 and 14. However, type 1 diabetes accounts for only about 5% of cases of diabetes mellitus. The onset of type 2 diabetes is usually gradual and tends to affect people over age 40, particularly those who are overweight. Infrequently, an adult may develop type 1 diabetes.
Location
Pancreas.
Complications
After 10 to 20 years of diabetes, patients are at risk of developing complications, such as vision disorders, kidney damage, and peripheral nerve degeneration (neuropathy). Strict control of blood glucose can delay or prevent these complications. Loss of sensation in the feet may allow injuries to go unchecked and become infected. In addition, people with diabetes are at increased risk for developing narrowing of the coronary arteries as well as narrowing of arteries supplying the brain and legs. The combination of foot infections and decreased blood supply can lead to gangrene (tissue death), which may require amputation.
Prophylaxis / Prevention
To prevent the development of type 2 diabetes, lose weight if you are more than 20% overweight, and maintain weight within healthy limits. Exercise regularly. There is no known way to prevent type 1 diabetes. People with either type of diabetes should get regular eye examinations to aid in early detection and treatment of diabetes-related vision disorders.
Prognosis
Diabetes mellitus (and its complications) is the fourth leading cause of death in the United States. Treatment is largely a process of self-management. Although there is no cure, almost all people with diabetes are able to control their symptoms and lead full, productive lives.
Medical Treatment
For type 1 diabetes: Daily injections of insulin are necessary. One to four daily injections are required to control blood glucose levels. Long-acting and rapid-acting insulin preparations are available: a combination of the 2 kinds is often prescribed. A strict diet and schedule of meals are necessary to control blood glucose levels. Your doctor may recommend a diet low in fat, salt, and cholesterol, and may advise you to see a nutritionist for dietary planning. Because both exercise and insulin lower glucose levels, exercise and insulin injections must be timed so that they do not combine to case a dangerous drop in blood sugar (hypoglycemia). Strict adherence to the timetable of injections, meals, and exercise is necessary for proper management of the disease.
For type 2 diabetes: A diet low in fat and other calories, in addition to regular exercise, is necessary to control weight. Oral hypoglycaemic drugs, such as tolbutamide, chlorpropamide, tolazamide, acetohexamide, glyburide, glipixzide, glimepiride, repaglinide, or meglitonide may be prescribed to increase insulin production by the pancreas, if exercise and diet do not lower glucose levels sufficiently. Other oral agents can reduce insulin resistance (metaformin, pioglitazone and rosiglitazone) or slow the absorption of sugars from the intestine (acarbose and miglitol). Insulin injections may be necessary in more severe cases of type 2 diabetes, or if a patient with type 2 diabetes contracts and additional illness. For both types of diabetes: Blood tests to measure glucose levels should be performed as your doctor recommends, one to four times a day. Your doctor will recommend a blood monitoring device to use at home. Careful attention must be paid to the risk factors for atherosclerosis because of its increased occurrence with diabetes. Those suffering from diabetes should not smoke, should reduce dietary saturated fat, cholesterol, and salt, and should take any medications prescribed for high blood pressure or high cholesterol levels. People with diabetes should drink generous amounts of water when stricken with another illness, such as the flu, to replace lost fluid and prevent diabetic coma. When ill, people with type 1 diabetes should test their urine for ketones every four to six hours. People with diabetes should practice good foot care and check their feet every day. Nerve damage from diabetes mellitus reduces sensation in the feet, and small foot problems may turn into major infections. Laser photocoagulation to prevent the rupture of tiny blood vessels in the eye may help prevent or treat diabetic retinopathy. Most patients with diabetes need an eye examination by an ophthalmologist at least once a year to detect the earliest manifestations of retinopathy. Dialysis, an artificial blood-filtering process, may be necessary to treat kidney failure. In advanced cases a kidney transplant may be advised. Amitriptyline, desipramine, or nortiptyline, medications usually used to treat depression, or the antiseizure medication gabapentin may be prescribed to relieve the pain in the limbs. Excellent control of blood glucose levels delays or prevents late complications affecting they eyes, kidneys, and nerves. Kidney damage can be slowed by controlling blood pressure and using ACE inhibitors.