Insulin
Biological or Clinical Significance:
Human insulin is a polypeptide hormone originating in the beta cells of the pancreas and serving as a principal regulator for the storage and production of carbohydrates. Its secretion is normally stimulated by increases in the amount of glucose in circulation. This leads to higher insulin levels and more rapid tissue-assimilation of glucose, followed by a decline in the insulin level as the glucose level subsides.
Type I diabetes mellitus is an autoimmune disease that leads to destruction of the beta cells, and loss of the insulin secretory response to increased circulating glucose levels. Type II diabetes mellitus is a disease caused by insulin resistance, i.e., there is a reduction in the ability of the cell to respond to increased circulating insulin. Measurement of circulating levels of insulin is not helpful in the diagnosis or monitoring of either type of diabetes. Insulin tends to circulate at inappropriately high levels in patients with insulin-secreting pancreatic tumors.
Principle of Test Method:
The human insulin assay is an automated sandwich immunoassay using electrochemiluminescent detection.