Block 3 - metabolic syndrome and glucose homeostasis (L1-2) Flashcards
What are the traditional risk factors for CVD?
dyslipidemia (high cholesterol)
obesity
hypertension (high BP)
smoking
diabetes
What are the other major clinical conditions which are risk factors for CVD?
insulin resistance and hyperinsulinemia
glucose intolerance
Most risk factors for CVD are also risk factors for…
Type 2 Diabetes
Do risk factors for T2D and CVD occur more often together or more often individually?
together
What are the major risk factors for both CVD and T2D?
high BP
dyslipidemia (high triglycerides and low HDL cholesterol)
raised fasting glucose
central obesity
What is the Metabolic Syndrome?
clustering of specific pathologies that represent and increased risk of CVD and therefore increased probability of heart attack or stroke
What are other names for the Metabolic Syndrome?
syndrome x
insulin resistance syndrome
cardio metabolic syndrome
What is the prevalence of metabolic syndrome?
40% of adults over 50 have it
What are the defining components of metabolic syndrome?
visceral (central) obesity
insulin resistance
hyperinsulinemia
glucose intolerance
dyslipidemia
essential hypertension
Besides the major components, what are other components of the metabolic syndrome?
adipocyte dysfunction
accelerated atherosclerosis
endothelial dysfunction
renal dysfunction
hepatic steatosis
inflammation
hypercoagulability
Describe visceral obesity as a core component of metabolic syndrome
increase in visceral (abdominal) adipose tissue
- closely associated with components of the metabolic syndrome, such as insulin resistance, due to adipose tissue-derived factors
assessment of overall overweight or obesity is done by BMI (kg/m^2), but this doesn’t reflect fat distribution
assessment of visceral obesity is done by waist circumference and MRI
The umbrella factor that all other components stem from is…
increase body size (BMI and central adiposity)
Describe the relationship between visceral fat and insulin sensitivity. What is the M value?
As adipose tissue volume increases, glucose disposal decreases
M value measures insulin sensitivity
Underweight individuals have a —– risk compared to normal weight individuals.
increased/higher
Describe insulin resistance as a core component of metabolic syndrome
the state in which normal or elevated circulating insulin does not elicit the expected response
What are the primary and other organs of insulin resistance?
primary - skeletal muscle
other - liver and adipose tissue
What qualifies someone as “pre-diabetic”? What effects does this have for them?
- insulin resistant but not showing signs of hyperglycemia due to compensatory hyperinsulinemia
- already at increased risk of heart attack and stroke
It often takes how long for diabetes to be diagnosed after the initial onset of visceral obesity? Why?
years to decades
It takes that long for insulin resistance to peak and then for fasting blood glucose levels to finally start rising and produce symptoms
Microvascular complications start to occur when…
fasting blood glucose begins to rise (diabetes), which is often years after glucose tolerance has been impaired
Describe hyperinsulinemia as a core component of metabolic syndrome
increase in insulin secretion compensates for the insulin resistance, keeping blood glucose as close to normal as possible
degree to achieve normal glucose regulation cannot be maintained over time, so a relative dysfunction in insulin secretion will allow hyperglycemia to develop (eventually insulin secretion wares out and also drops, so then blood sugar goes up)
Describe glucose intolerance as a core component of metabolic syndrome
abnormal response to an oral glucose tolerance test (OGTT, ingestion of 75g glucose and assessing the blood glucose over the next 2-3 hours)
with impaired glucose tolerance, glucose levels increase higher than normal and stay high for longer than normal