Hypoglycemia; Iatrogenic clinical trials

Liver Glycogen and Hypoglycemia in Humans

The purpose of this research study is to learn more about how sugar levels in the liver affect the ability of people both with and without type 1 diabetes. People with type 1 diabetes do not make their own insulin, and are therefore required to give themselves injections of insulin in order to keep their blood sugar under control. However, very often people with type 1 diabetes give themselves too much insulin and this causes their blood sugar to become very low, which can have a negative impact on their health. When the blood sugar becomes low, healthy people secrete hormones such as glucagon and epinephrine (i.e., adrenaline), which restore the blood sugar levels to normal by increasing liver glucose production into the blood. However, in people with type 1 diabetes, the ability to release glucagon and epinephrine is impaired and this reduces the amount of sugar the liver is able to release. People with type 1 diabetes also have unusually low stores of sugar in their livers. It has been shown in animal studies that when the amount of sugar stored in the liver is increased, it increases the release of glucagon and epinephrine during insulin-induced hypoglycemia. In turn, this increase in hormone release boosts liver sugar production. However, it is not known if increased liver sugar content can influence these responses in people with and without type 1 diabetes. In addition, when people with type 1 diabetes do experience an episode of low blood sugar, it impairs their responses to low blood sugar the next day. It is also unknown whether this reduction in low blood sugar responses is caused by low liver sugar levels. The investigators want to learn more about how liver sugar levels affect the ability to respond to low blood sugar.