Pathophysiology + Screening Flashcards
Diabetes Mellitus is classified as a ____ disorder
Metabolic
DM is characterized by the presence of… due to these factors.
Presence of hyperglycemia, due to defective insulin secretion, insulin action, or both
The major cells of the pancreas involved with blood glucose control are the…
Islet cells
The two most important part of islet cells are:
Alpha + beta cells
Delta cells are not talked about much
Beta cells produce…
Insulin
And amylin (satiety)
Alpha cells produce…
Glucagon
Insulin is released in response to…
Elevated BG levels
Bring back up to normal euglycemia
Glucagon is released in response to…
Low BG levels
Bring back up to euglycemia
In terms of the fed and fasting states, insulin and glucagon are released…
Insulin = fed state
Glucagon = fasting state
Insulin works as a lock + key, meaning…
Insulin is the key to get glucose into cells
The major site of glucose uptake is…
Skeletal muscle
After insulin stimulates uptake of glucose in skeletal muscle, the glucose is then stored as…
Stored as glycogen +Glycogen, and used in energy metabolism (glycogenesis)
Insulin also stimulates production of proteins from AA’s
Formation of glucose from a non-carb source usually occurs in-between meals, via…
Proteins - amino acids converted to glucose via gluconeogenesis
Insulin is involved with the liver after meals via…
Stimulation of liver to store glucose as glycogen (glycogenesis)
And suppresses gluconeogenesis
In a fasting state, glucagon is involved with the liver via…
Glucagon stimulates liver to provide glucose by glycogenolysis (glycogen back into glucose) and gluconeogenesis (formation of glucose from non-carb, like amino acids)
If the amount of glucose entering the liver is greater than storage capacity for glycogen, insulin will help by…
Promoting glucose conversion to fatty acids, stored in adipose tissue
Glycerol phosphate + Free fatty acids stored as TG’s
In starvation or insulin deficiency, lipolysis can occur, which is when…
TG’s split back to glycerol and FFA’s, FFA metabolized and ketone bodies used as energy source
Insulin has antilypolytic properties
The brain has a strong connection to glucose as…
Glucose is its main energy source
does not depend on presence of insulin for use
Type 1 DM (T1DM) is characterized by…
An absolute lack of insulin secretion
T1DM is primarily caused by…
Autoimmune beta-cell destruction
Markers of immune destruction are often present in T1DM, which may include…
Islet cell antibodies, insulin antibodies, GAD antibodies
GAD = glutamic acid decarboxylase
After initiation of insulin, some T1DM patients go through a honeymoon phase, where…
Insulin secretion recovers temporarily + insulin requirements may be quite low
The honeymoon phase can occur ____ after initiation of insulin, and last for _____
Days-weeks following initiation, and last for months
An important factor about the honeymoon phase in T1DM patients is that…
The period is transient - so need to continue receiving insulin + monitor for hypoglycemia
Prediabetes is defined as…
An intermediate state between normal glucose levels and diabetes
Strong predictor of T2DM and CVD
Diagnosis of prediabetes via fasting plasma glucose is…
Numbers
6.1-6.9 mmol/L
Impaired fasting glucose (IFG)
Diagnosis of prediabetes after 2h prandial glucose is…
Numbers
7.8-11.0
Impaired glucose tolerance (IGT)
Diagnosis of prediabetes based off of A1C is…
Numbers
6.0-6.4%
Type 2 Diabetes results from a combination of…
Impaired insulin secretion and insulin resistance
Impaired secretion from too much resistance is common
T2DM often manifests only in those who lose the ability to…
Produce sufficient qualities of insulin to maintain euglycemia in face of insulin resistance
Key environmental factors that may lead to development of T2DM include…
Excessive caloric intake
Sedentary lifestyle
There are many risk factors for T2DM development, but a key risk factor is…
Abdominal obesity
Insulin resistance is found in most obese people
BMI often correlates with degree of insulin resistance
Impaired insulin secretion in response to food in T2DM occurs because of…
Impaired beta-cell function
Reduced stimulus from incretin hormones
Incretin hormones tells pancreas to pump out insulin
Consequences of defective insulin secretion is…
Hyperglycemia
First, see elevated post-prandial, then elevated fasting
Insulin resistance is simply classified as…
Lowered sensitivity to actions of insulin by target tissues
Skeletal muscle is related to insulin resistance as…
Skeletal muscle is the primary site of insulin resistance, with decreased glucose uptake
The liver is related to insulin resistance as…
It results in inability to suppress hepatic glucose production
Adipose tissue is related to insulin resistance, as…
Adipocytes become resistant to anti-lypolytic effects of insulin, leading to increased lipolysis
FFA in circulation can end up stimulating liver glucose production, impair skeletal muscle sensitivity, and impair insulin release - WORSENING overall condition
T1DM usually presents with…
Duration?
Acute symptoms of short duration
Presentation of symptoms that usually occur in T1DM include…
Frequent urination, hunger, and thirst
Fatigue, blurred vision, infection
Body systems + cells are not receiving any energy source
Urination due to osmotic diuresis
A serious complication that may arise after several days of T1DM symptoms is:
Diabetic ketoacidosis (DKA)
Presentation of T2DM differs from T1DM, as…
Asymptomatic presentation is common and often discovered incidentally
Possible symptoms or complications that may present with T2DM include:
Frequent urination, thirst
Established diabetic complications at diagnosis
Depends on how high BG is
Gestational diabetes is a condition that…
Develops during pregnancy
Cause of gestational diabetes is primarily due to…
Insulin resistance
Gestational DM may cause complications, such as…
Increased risk of fetal hyperinsulinemia, hypoglycemia
Increased risk of developing T2DM in mother and child
Are there any preventative measures for T1DM?
No successful preventive interventions so far
The most effective measure of preventing T2DM is…
Lifestyle modifications
Medications may also help in some people with pre-diabetes
Screening for T1DM is…
Good? Not good? And why?
Not recommended
Overall low prevalence, no identifiable intervention
Screening for T2DM is…
Good? Not good? Why?
Important!
Large amount of people are undiagnosed
Initial screening tests for T2DM should include…
FPG or A1C
CANRISK is…
A risk assessment questionaire to help assess risk of having prediabetes or T2DM
Identify patients who should be referred to physicians for work-up
Diagnosis of diabetes using FPG is…
FPG > 7.0 mmol/L
Fasting = no caloric intake for at least 8 hours
Diagnosis of diabetes using A1C is…
A1C > 6.5%
Diagnosis of diabetes using 2h PG in a 75g OGTT is…
> 11.1 mmol/L
Diagnosis of diabetes using a random PG is…
> 11.1 mmol/L
Disadvantages of using FPG for screening includes:
Inconvenience
Less sensitivity compared to OGTT
Advantages of using A1C for screening includes:
Convenience
Better predictor of CVD
No day-to-day variability
Disadvantages of using A1C for screening includes:
Cost
Not valid for all medical conditions/populations
Ethnicity + aging may alter A1C
Advantages of using OGTT for screening includes:
Established standard, sensitive
Disadvantages of using OGTT for screening includes:
Inconvenience
Taste, cost
