Glycogen metabolism, as well. In hypoglycemia caused by excessive insulin, liver glycogen levels are high, but the high insulin levels prevent the glycogenolysis necessary to maintain normal blood sugar levels. Glucagon is a common treatment for this type of hypoglycemia. Various inborn errors of metabolism are caused by deficiencies of enzymes necessary for glycogen synthesis or breakdown. These are collectively referred to as glycogen storage diseases. Long-distance athletes, such as marathon runners, cross-country skiers, and cyclists, often experience glycogen depletion, where almost all of the athlete's glycogen stores are depleted after long periods of exertion without sufficient carbohydrate consumption. This phenomenon
Adult polyglucosan body disease Adult polyglucosan body disease Adult polyglucosan body disease (APBD) is an orphan disease and a glycogen storage disorder that is caused by an inborn error of metabolism. Symptoms can emerge any time after the age of 30; early symptoms include trouble controlling urination, trouble walking, and lack of sensation in the legs. People eventually develop dementia. A person inherits loss-of-function mutations in the "GBE1" gene from each parent, and the lack of glycogen branching enzyme (the protein encoded by "GNE1") leads to buildup of unbranched glycogen in cells, which harms neurons more than other kinds of cells. Most people first