Diabetes is a disease that affects the body's ability to regulate blood sugar. There are two types of diabetes that vary slightly in their chemistry and manifestations, as well as in their methods of management and treatment. Regardless, both type 1 and type 2 diabetes are characterized by and associated with the same set of biological molecules.
Glucose
Of the many biological molecules involved in diabetes, glucose is perhaps the most central. It's the most ubiquitous of the sugar molecules---in fact, it's a constituent of table sugar and is the building block for all starch. Glucose is commonly called "blood sugar," and it's an important fuel for all body cells, particularly the brain cells, for which glucose is the primary source of nutrition. To ensure that all body and brain cells have constant access to nutrition, the body carefully regulates glucose concentration in the blood. In diabetes, these regulatory processes are disturbed, and blood glucose concentrations can easily get too high or too low, leading to disease symptoms.
Insulin
Insulin is a hormone, or biological signaling molecule. Biochemists Reginald Garrett, Ph.D. and Charles Grisham, Ph.D. describe it as a protein---biochemically similar to the protein that comprises muscle, but quite different in function. Insulin is produced by the pancreas, a body organ that makes digestive juices and several hormones. The primary role of insulin is to signal cells to take up blood sugar in accordance with their energy needs---insulin is typically secreted by the pancreas after eating. Both types of diabetes result from insulin-related problems; in type 1 diabetes, the pancreas is unable to produce insulin, while in type 2 diabetes, the cells are unable to respond to insulin. For this reason, type 1 diabetes can be managed with insulin injections to replace the missing hormone, but type 2 diabetics do not benefit from supplementation, since they already produce the hormone on their own. Dr. R. Lawrence, in his seminal 1951 work "Type of Human Diabetes," notes that insufficient insulin treatment in type 1 diabetics leads to hyperglycemia---high blood sugar---and coma.
Glucagon
A second pancreatic hormone involved in diabetes is glucagon. This biological molecule has an action nearly opposite to that of insulin---it causes specialized liver cells to release stored glucose, and raises blood sugar. Paradoxically, glucagon levels can be quite high in diabetics, according to a 1969 study in the "American Journal of the Medical Sciences." Since diabetics have difficulty getting sugar from the blood into the cells because of insulin deficiency or insensitivity, cells send "starvation" signals, which result in the release of glucagon. Blood sugar increases as glucose floods the bloodstream from its storage point in the liver, but glucagon in incapable of helping cells take up any of that glucose, and the cells remain sugar-starved. The glucagon signals exacerbate already high blood sugar, however, which can be very damaging to cells.
Ketone Bodies
Acetone, a common ingredient in fingernail polish and polish remover, is an example of a ketone body---a class of biological molecules that are produced inside some cells as fat is broken down. Normally, these ketone bodies don't enter systemic circulation, but in the case of diabetes, starving brain cells send such a strong distress signal that ketone bodies are released into the blood. They then travel to the brain, where they can be taken up and used as an emergency energy source. This is called ketosis, notes Dr. Lawrence, and typically accompanies extremely high blood sugar. While ketosis itself isn't necessarily dangerous, it indicates an extreme level of cellular starvation that is quite dangerous.
References
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
- "British Medical Journal"; Types of human diabetes; R. Lawrence, February 1951.
- "American Journal of the Medical Sciences"; Pancreatic Glucagon Secretion in Normal and Diabetic Subjects; E. Aguilar-Parada et al; June 1969
