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.