Diabetes Mellitus - Understanding Causes, Symptoms and Treatment

As of the year 2000, according to the World Health Organization, at least 171 million people worldwide suffer from diabetes. For at least 20 years, diabetes rates in North America have been increasing rapidly. In 2010 nearly twenty six million people have diabetes in the United States alone, and seven million people remain undiagnosed. Another fifty seven million people are estimated to have pre-diabetes. Diabetes mellitus occurs throughout the world, but is more common in the more developed countries.

The Centers for Disease Control has termed the growth in the number of diabetic patients an epidemic.The National Diabetes Information Clearing house estimates that diabetes costs $132 billion in the United States alone every year. Approximately 10% of diabetes cases in North America are type 1, with the rest being type 2. It is estimated that one in three Americans born after 2000 will develop diabetes in their lifetime.

There are three main types of diabetes:

Type 1 diabetes:results from the body's failure to produce insulin, and presently requires the person to inject insulin. (Also referred to as insulin-dependent diabetes mellitus, IDDM for short, and juvenile diabetes.)Type 2 diabetes:results from insulin resistance, a condition in which cells fail to use insulin properly, sometimes combined with an absolute insulin deficiency. (Formerly referred to as non-insulin-dependent diabetes mellitus, NIDDM for short, and adult-onset diabetes.)Gestational diabetes:is when pregnant women, who have never had diabetes before, have a high blood glucose level during pregnancy. It may precede development of type 2 diabetes mellitus.

Causes: The cause of diabetes depends on the type.Insulin is the principal hormone that regulates uptake of glucose from the blood into most cells (primarily muscle and fat cells, but not central nervous system cells). Therefore deficiency of insulin or the insensitivity of its receptors plays a central role in all forms of diabetes mellitus.

Type 1 diabetes is partly inherited and then triggered by certain infections, with some evidence pointing at Coxsackie B4 virus which can trigger a reaction which results in destruction of the insulin-producing beta cells of the pancreas. There is a genetic element in individual susceptibility to some of these triggers which has been traced to particular the genetic "self" identifiers relied upon by the immune system. However, even in those who have inherited the susceptibility, type 1 diabetes mellitus seems to require an environmental trigger.

Humans are capable of digesting some carbohydrates, in particular those most common in food; starch, and some carbohydrates such as sucrose, are converted within a few hours to simpler forms most notably the glucose (blood sugar), the principal carbohydrate energy source used by the body. The rest are passed on for processing by gut flora (microorganisms) largely in the colon. Insulin is released into the blood by beta cells (ß-cells), found in the Islets of Langerhans (regions of the pancreas that contain its endocrine (i.e., hormone-producing) cells in the pancreas, in response to rising levels of blood glucose, typically after eating. Insulin is used by about two-thirds of the body's cells to absorb glucose from the blood for use as fuel, for conversion to other needed molecules, or for storage.

Symptoms: The classical symptoms of diabetes are polyuria(frequent urination), polydipsia (increased thirst) and polyphagia (increased hunger). Symptoms may develop rapidly (weeks or months) in type 1 diabetes while in type 2 diabetes they usually develop much more slowly and may be subtle or absent.

Prolonged high blood glucose causes glucose absorption, leads to changes in the shape of the lenses of the eyes, resulting in vision changes; sustained sensible glucose control usually returns the lens to its original shape. Blurred vision is a common complaint leading to a diabetes diagnosis; type 1 should always be suspected in cases of rapid vision change, whereas with type 2 change is generally more gradual, but should still be suspected.

The most common symptoms of diabetes mellitus are those of fluid imbalance leading to urinary frequency and dehydration. Severe dehydration causes weakness, fatigue, and mental status changes. Symptoms may come and go as plasma glucose levels fluctuate. Hyperglycemia (high blood sugar) can also cause weight loss, nausea and vomiting, and blurred vision, and it may predispose to bacterial or fungal infections.

Treatment: Diabetes mellitus is a chronic disease which cannot be cured except in very specific situations but as of 2011 but a lot of research is in progress. It is associated with an impaired glucose cycle that alters the patient's metabolism. Management concentrates on keeping blood sugar levels as close to normal as possible, without causing hypoglycemia (under-sweet blood). Management of this disease may include carefully managing diet, exercising, taking oral diabetes medication, using some form of insulin, and maintaining proper circulation in the extremities. The disease may be further complicated by other external factors such as stress, illness, menses, injection site scarring, and other physiological factors unique to individual patients.

Insulin is also the principal control signal for conversion of glucose to glycogen, a molecule that serves as the secondary long-term energy storage facility in liver and muscle cells. Lowered glucose levels result both in the reduced release of insulin from the beta cells and in the reverse conversion of glycogen to glucose when glucose levels fall. This is mainly controlled by the hormone glucagon which acts in the opposite manner to insulin. Glucose is forcibly produced from internal liver cell stores (as glycogen) re-enters the bloodstream. Normally liver cells do this when the level of insulin is low (which normally correlates with low levels of blood glucose).

Higher insulin levels increase some anabolic ("building up") processes such as cell growth and duplication, protein synthesis, and fat storage. Insulin (or its shortage) is the principal signal in converting many of the bidirectional processes of metabolism from a catabolic (reducing to smaller elements such as fatty acids or amino acids) to an anabolic direction, and vice versa. In particular, a low insulin level is the trigger for entering or leaving ketosis (the fat burning metabolic phase).