Diabetes mellitus is a group of metabolic diseases characterized by high blood sugar (glucose) levels that result from defects in insulin secretion, or its action, or both. Diabetes mellitus, commonly referred to as diabetes was first identified as a disease associated with "sweet urine," and excessive muscle loss in the ancient world. Elevated levels of blood glucose (hyperglycemia) lead to spillage of glucose into the urine, hence the term sweet urine.
Normally, blood glucose levels are tightly controlled by insulin, a hormone produced by the pancreas. Insulin lowers the blood glucose level. When the blood glucose elevates (for example, after eating food), insulin is released from the pancreas to normalize the glucose level. In patients with diabetes, the absence or insufficient production of insulin causes hyperglycemia. Diabetes is a chronic medical condition, meaning that although it can be controlled, it lasts a lifetime.
The early symptoms of untreated diabetes are related to elevated blood sugar levels, and loss of glucose in the urine. High amounts of glucose in the urine can cause increased urine output and lead to dehydration. Dehydration causes increased thirst and water consumption.
The inability of insulin to perform normally has effects on protein, fat and carbohydrate metabolism. Insulin is an anabolic hormone, that is, one that encourages storage of fat and protein.
A relative or absolute insulin deficiency eventually leads to weight loss despite an increase in appetite.
Some untreated diabetes patients also complain of fatigue, nausea and vomiting.
Patients with diabetes are prone to developing infections of the bladder, skin, and vaginal areas.
Fluctuations in blood glucose levels can lead to blurred vision. Extremely elevated glucose levels can lead to lethargy and coma.
HOW IS DIABETES DIAGNOSED?
The fasting blood glucose (sugar) test is the preferred way to diagnose diabetes. It is easy to perform and convenient. After the person has fasted overnight (at least 8 hours), a single sample of blood is drawn and sent to the laboratory for analysis. This can also be done accurately in a doctor's office using a glucose meter.
When fasting blood glucose stays above 100mg/dl, but in the range of 100-126mg/dl, this is known as impaired fasting glucose (IFG). While patients with IFG do not have the diagnosis of diabetes, this condition carries with it its own risks and concerns, and is addressed elsewhere.
HEMOGLOBIN A1C (HbA1C)
In the blood stream, red blood cells contain haemoglobin. Glucose sticks to the haemoglobin to make a 'Glycosylated haemoglobin' molecule, called haemoglobin A1C or HbA1C. The more glucose in the blood, the more haemoglobin A1C or HbA1C will be present in the blood. When sugar sticks to these cells, it gives us an idea of how much sugar is present in the bloodstream for the preceding three months. In most labs, the normal range is 4%-5.9 %. In poorly controlled diabetes, its 8.0% or above, and in well controlled patients it's less than 7.0% (optimal is less than 6.5%).The benefits of measuring A1c is that is gives a more reasonable and stable view of what's happening over the course of time (three months), and the value does not vary as much as finger stick blood sugar measurements
The American Diabetes Association currently recommends an A1c goal of less than 7.0% with A1C goal for selected individuals of as close to normal as possible (less than 6%) without significant hypoglycemia. Other Groups such as the American Association of Clinical Endocrinologists feel that an A1c of less than 6.5% should be the goal.
Insufficient production of insulin (either absolutely or relative to the body's needs), production of defective insulin (which is uncommon), or the inability of cells to use insulin properly and efficiently leads to hyperglycemia and diabetes. This latter condition affects mostly the cells of muscle and fat tissues, and results in a condition known as insulin resistance. This is the primary problem in type 2 diabetes. The absolute lack of insulin, usually secondary to a destructive process affecting the insulin-producing beta cells in the pancreas, is the main disorder in type 1 diabetes.
TYPES OF DIABETES
TYPE 1 DIABETES
It is also called Insulin Dependent Diabetes Mellitus (IDDM) or Juvenile-onset Diabetes. A condition characterized by high blood glucose levels caused by a total lack of insulin. It occurs when the body's immune system attacks the insulin-producing beta cells in the pancreas and destroys them. The pancreas then produces little or no insulin.
TYPE 2 DIABETES
It is also called Non-Insulin Dependent Diabetes Mellitus (NIDDM) or Adult-onset Diabetes. It results from reduced insulin secretion from the β-cells of the ‘islets of langerhans’ of pancreas or insulin resistance, a condition in which cells fail to use insulin properly.