Diabetes Mellitus
What is diabetes?
Diabetes mellitus is a group of metabolic diseases characterized by high blood sugar (glucose) levels that result from defects in insulin secretion, or 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, but can be controlled through diet, exercise, supplements and medication.
Different Types of Diabetes
There are two major types of diabetes, called
• Type 1
Type 1 diabetes was also called insulin dependent diabetes mellitus (IDDM), or juvenile onset diabetes mellitus.
In type 1 diabetes, the pancreas undergoes an autoimmune attack by the body itself, and is rendered incapable of making insulin.
Abnormal antibodies have been found in the majority of patients with type 1 diabetes. Antibodies are proteins in the blood that are part of the body's immune system.
The patient with type 1 diabetes must rely on insulin medication for survival.
In autoimmune diseases, such as type 1 diabetes, the immune system mistakenly manufactures antibodies and inflammatory cells that are directed against and cause damage to patients' own body tissues.
In persons with type 1 diabetes, the beta cells of the pancreas, which are responsible for insulin production, are attacked by the misdirected immune system.
It is believed that the tendency to develop abnormal antibodies in type 1 diabetes is, in part, genetically inherited, though the details are not fully understood.
• Type 2.
Type 2 diabetes was also referred to as non-insulin dependent diabetes mellitus (NIDDM), or adult onset diabetes mellitus (AODM).
In type 2 diabetes, patients can still produce insulin, but do so relatively inadequately for their body's needs, particularly in the face of insulin resistance as discussed above.
In many cases this actually means the pancreas produces larger than normal quantities of insulin.
A major feature of type 2 diabetes is a lack of sensitivity to insulin by the cells of the body (particularly fat and muscle cells).
In addition to the problems with an increase in insulin resistance, the release of insulin by the pancreas may also be defective and suboptimal.
In fact, there is a known steady decline in beta cell production of insulin in type 2 diabetes that contributes to worsening glucose control.
(This is a major factor for many patients with type 2 diabetes who ultimately require insulin therapy.)
Finally, the liver in these patients continues to produce glucose through a process called gluconeogenesis despite elevated glucose levels.
The control of gluconeogenesis becomes compromised.
• Gestational diabetes
Diabetes can occur temporarily during pregnancy. Significant hormonal changes during pregnancy can lead to blood sugar elevation in genetically predisposed individuals.
Blood sugar elevation during pregnancy is called gestational diabetes.
Gestational diabetes usually resolves once the baby is born.
However, 25%-50% of women with gestational diabetes will eventually develop type 2 diabetes later in life, especially in those who require insulin during pregnancy and those who remain overweight after their delivery.
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