Defects in Insulin secretion and action Flashcards
what defect is seen in Type 1 diabetes
autoimmune destruction of pancreatic beta cells
what defect is seen in Type 2 diabetes
beta cells try to compensate of hyperglycaemia caused by insulin resistance, so usually presents with hyperinsulinemia
what defect is seen in Gestational diabetes
declining beta cell function and associated with high risk of later T2DM
what defect is seen in Maturity onset diabetes of the young(MODY)
monogenic disease with some features of both type 1 and 2 diabetes, beta cell dysfunction but not autoimmune
what defect is seen in neonatal diabetes
monogenic diabetes caused by mutation in the glucose sensing mechanism
what 2 proteins do Katp channels consist of
Kir6 = an inward rectifier subunit
SUR1 = sulphonylurea receptor
(both required for normal function)
what defects can occur in the proteins of the Katp channel
Kir6 mutation can cause neonatal diabetes
Kir6 or SUR1 mutation can cause hyperinsulinemia
what drugs inhibit and stimulate Katp
inhibit = sulphonylureas stimulate = diazoxide
how is glucokinase affected in MODY
glucokinase activity impaired, glucose sensing defect, blood glucose threshold for insulin secretion is increased
describe what insulin resistance means
this is when higher than normal levels of insulin are required to achieve insulin actions
how does insulin resistance primarily occur
through reduced insulin sensing and/or signalling
what is the most common cause/association of insulin resistance
obesity
what defect is seen in leprechaunism/Donohue syndrome
mutation in gene for insulin receptor, severe insulin resistance
(rare)
what defect is seen in Rabson Mendenhall syndrome
severe insulin resistance, hyperglycaemia and compensatory hyperinsulinemia
(rare)
