An extract on #oceanvibes
Although other cells can use other fuels (most prominently fatty acids), neurons depend on glucose as a source of energy, unless the person is in ketosis. They do not require insulin to absorb glucose, unlike muscle and adipose tissue, and they have very small internal stores of glycogen. Glycogen stored in liver cells (unlike glycogen stored in muscle cells) can be converted to glucose, and released into the blood, when glucose from digestion is low or absent, and the glycerol backbone in triglycerides can also be used to produce blood glucose.
Sufficient lack of glucose and scarcity of these sources of glucose can dramatically make itself manifest in the impaired functioning of the central nervous system: dizziness, speech problems, and even loss of consciousness. Low blood glucose level is known as hypoglycemia or, in cases producing unconsciousness, "hypoglycemic coma" (sometimes termed "insulin shock" from the most common causative agent). Endogenous causes of insulin excess (such as an insulinoma) are very rare, and the overwhelming majority of insulin excess-induced hypoglycemia cases are iatrogenic and usually accidental. A few cases of murder, attempted murder, or suicide using insulin overdoses have been reported, but most insulin shocks appear to be due to errors in dosage of insulin (e.g., 20 units instead of 2) or other unanticipated factors (did not eat as much as anticipated, or exercised more than expected, or unpredicted kinetics of the subcutaneously injected insulin itself).
Possible causes of hypoglycemia include:
External insulin (usually injected subcutaneously)
Oral hypoglycemic agents (e.g., any of the sulfonylureas, or similar drugs, which increase insulin release from -cells in response to a particular blood glucose level)
Ingestion of low-carbohydrate sugar substitutes in people without diabetes or with type 2 diabetes. Animal studies show these can trigger insulin release, albeit in much smaller quantities than sugar, according to a report in Discover magazine, August 2004, p 18. (This can never be a cause of hypoglycemia in patients with mature type 1 diabetes, since there is no endogenous insulin production to stimulate. It can occur during the honeymoon period, a period up to several years after a type 1 diabetes diagnosis during which endogenous insulin production still occurs.)
Use of insulin pumps is increasing because of:
Easy delivery of multiple insulin injections for those using intensive insulin therapy.
Accurate delivery of very small boluses, helpful for infants.
Growing support among doctors and insurance companies due to the benefits contributing to reducing the incidence of long-term complications.
Improvements in blood glucose monitoring. New meters require smaller drops of blood, and the corresponding lancet poke in the fingers is smaller and less painful. These meters also support alternate site testing for the most routine tests for practically painless testing. This compensates for the need for pump users to test blood sugar more frequently.