Diabetes Mellitus Flashcards
Insulin is the primary _____ hormone of the body
anabolic
What processes does insulin regulate?
carbohydrate utilization/ storage
protein synthesis
lipogenesis
What hormones are counter-regulatory to insulin?
epinephrine
cortisol
growth hormone
Describe the regulation of glucose release from pancreatic beta cells
- glucose is transported into the beta cell, enters glycolysis and generates ATP.
- increased ATP closes an ATP-sensitive membrane potassium channel
- K channel closure depolarizes the cell, which then opens voltage-dependent calcium channels and triggers insulin secretion.
Insulin response to a constant glucose simulus is _______
biphasic:
early peak and more prolonged second phase
What are initiators of insulin release?
glucose
some amino acids
sulfonylureas- stimulate closer of K channel
What are inhibitors of insulin release?
somatostatin
epinephrine
K channel openers ex diazoxide
What cell types do NOT have insulin receptors
kidney, nerve, retina
What are the four categories of DM?
type 1- autoimmune
type 2- metabolic syndrome
“other”
gestational
Diabetes mellitus is defined by the degree of _________
hyperglycemia
What kinds of deficits can cause “other” DM?
defects in insulin action defects in B cell function (MODYs) drugs infections- CMV, rubella endocrinopathies
What are the diagnostic criteria for DM?
- A1c > 6.5%
- FPG > 125
- two hour plasma glucose >200 for OGTT
- any random plasma glucose >200 in symptomatic patient
What are the parameters for impaired fasting glucose (IFG)?
fasting glucose above 100 but below 126
What are the parameters for impaired glucose tolerance (IGT)?
plasma glucose between 140 and 200 two hours into OGTT
People with _____ are at increased risk for developing frank diabetes
pre-diabetes
People with _____ are at increased risk for developing frank diabetes
pre-diabetes
In type 1 diabetes, autoimmune destruction of B cells leads to:
absolute insulin deficiency
What HLA haplotypes are associated with type 1 diabetes?
DR3, DR4, DQ8
What antibodies can be found in type 1 diabetes?
insulin autoantibodies, islet cell antibodies, and anti-glutamic acid decarboxylase (GAD) antibodies
80-90% of beta cells are destroyed before ______ develops in type 1 diabetes
hyperglycemia
What is the renal threshold for glycosuria?
200
Describe effects of absolute insulin deficiency in type 1 diabetes
protein degradation, lipolysis, and inability to maintain body tissue, resulting in weight loss
osmotic diuresis
Type 1 diabetes symptoms are usually present for _____ before diagnosis
days- few weeks
What are the two major physiologic abnormalities in type 2 diabetes?
insulin resistance
impaired insulin secretion
The pathophysiological manifestations of type 2 diabetes occur at the level of the ____ and ________
liver and peripheral tissues- adipose and muscle
What is the major cause of fasting hyperglycemia in people with type 2 diabetes?
insulin resistance causes increased hepatic glucose production via gluconeogenesis and glycogenolysis