Diabetes Mellitus Overview

Study Notes

A group of metabolic diseases that cause hyperglycemia due to a deficiency in insulin secretion, insulin action, or both.
The primary cause of diabetes is either an inability to produce insulin or the inability of the body to effectively use the insulin produced.

Initially classified as Type 1 (Insulin-dependent diabetes mellitus - IDDM) and Type 2 (Non-insulin dependent diabetes mellitus - NIDDM)
The ADA/WHO classification (1995) eliminated IDDM and NIDDM and instead adopted Arabic numerals.

Type 1 Diabetes Mellitus
- Characterized by hyperglycemia resulting from pancreatic islet β-cell destruction, leading to absolute insulin deficiency.
- Accounts for 10-20% of all diabetes cases.
- Often diagnosed in childhood or adolescence (juvenile diabetes).
- Patients are often underweight.
- Prone to developing ketoacidosis.
- May be present in one or more marker (examples: islet cell antibodies, insulin antibodies).
Type 2 Diabetes Mellitus
- Characterized by hyperglycemia due to insulin resistance and a relative insulin deficiency.
- Accounts for the majority of diabetes cases.
- Diagnosed in adulthood.
- 80-90% of patients are overweight
Secondary Diabetes
- Results from another medical condition or due to the treatment of a medical condition that causes abnormal blood glucose levels.
- Can be induced by conditions such as Cushing Syndrome (e.g. steroid administration), Hyperthyroidism, or Parenteral Nutrition

Definition: Any degree of glucose intolerance that occurs during pregnancy in women without a previous history of diabetes.
Cause: Metabolic and hormonal changes during pregnancy.