Topic 8: Metabolic Syndrome Flashcards
Indicate the extent to which prevalence of obesity has increased in western countries over the past 30 years
Since 1975 it has trippled
2016 39% of adults aged 18 and over were overweight and 13% were obese
Most of the population of world lives in countries where overweight and obesity kills more than underweight
Identify the 5 factors that are considered in evaluating if a person has metabolic syndrome and state how many
of these need to be met to diagnose this syndrome
- Waist circumference: >102 males, >88 females
- triglycerides: >1.7 mmol/L
- blood pressure: >130 SBP or >85 DBP
- HDL cholesterol: <1.0 mmol/L male, <1.3 mmol/L female
- blood sugar: fasting glucose > 5.6 mmol/L
Need to be met:
- waist circumference,
- blood pressure and
- fasting trigylceride
Identify the major medical conditions that individuals with metabolic syndrome are at greater risk of developing
Heart Disease
Stroke
Type 2 Diabetes
Of the 5 risk factors for metabolic syndrome which is most commonly (a) measured (b) not measured
a) waist circumference, blood pressure and fasting triglyceride
b) HDL cholesterol, blood sugar
State the values for blood pressure (systolic & diastolic) and waist circumference (M and F Caucasian) above
which these become risk factors for metabolic syndrome
Blood pressure
SBP >130
DBP >85
Waist circumference
Males >102
Females >88
In addition to over-eating and physical inactivity, summarise other factors that can lead to obesity
- genetics - leptin deficiency
- childhood weight
- medications - antidepressants
- hormones - OCP
Explain the difference between visceral and subcutaneous fat and the relevance of waist/hip ratio
Visceral fat: lies between abdominal organs and in tissue called the omentum
Subcutaneous fat: is between the skin and the out abdominal wall
Relevance to waist/hip:
- quicky measurement adn indicator of visceral fat which is linekd to chronic diseases such as CHD, hypertension and diabetes
• State what best explains the current “obesity epidemic“ with terms of social trends in the last 30 years
Fueled by
economic growth
industrialisation - mechanised transport
sedentary lifestyle (office jobs)
processed & fast foods
high calorie foods
• Contrast healthy/unhealthy expansion of adipocytes in terms of (a) size (b) adiponectin levels (c) insulin
resistance
Healthy
- Size: small
- Adiponectin levels: high balanced hyperplasia/hypertrophy
- Insulin resistance: sensitive
Unhealthy
- Size: hypertrophic adipocytes - large
- Adiponectin levels: low
- Insulin resistance: insulin resistant
• State what is meant by lipotoxicity identifying the primary underlying cause of this state
Accumulation of excess fatty acids/tryglycerides in non-adipose tissue
Caused when nonadipose cells are exposed to chronic elevation of FFAs - diabetes
Identify the impact of lipotoxicity on the function of: heart, vasculature, liver, pancreas, skeletal muscle & kidney
HEART: coronoary atherosclerosis & CVD = decreased diastolic filling and increased epicardial fat
VASCULATURE: atherscolerosis and CVDs, icnreased SNS activty and BP
LIVER: steatosis, inflammation = Increased oxidaitve stress and VLDL production
PANCREAS: beta cell dysfunction and increased insulin resistance
SKELETAL MUSCLE: insulin resistance and decreased ATP synthesis
KIDNEY: inflammation and TNF a, I-6,, apoptosis and Fibrosis
State the impact of diabetes mellitus (DM) on glucose transport into cells and its impact on cellular and blood levels
Impaired glucose transport in diabetes is secondary to intracellular transporter depletion and to the presence of inhibitory factors interfering with the full expression fo glucose transporters at the plasma membrane contributing to postreceptor insulin resistance
Blood glucose levels is impacted by carbohydrate ingestion and regulated by insulin
Identify the 2 hormones that regulate blood glucose levels, indicating their sites of production (incl. cell types) and their principal impacts on
glucose metabolism
Summarise how these 2 hormones regulate blood glucose levels identifying their principal target tissues/organs
The pancrease produces Insulin and glucagon to stabilise blood sugar levels
Insuin helps the cells absorb glucose, reducing blood sugar and providing cells with glucose for energy.
When blood sugar levels are too low, glycagon instructs liver to released stored glucose causing rise in blood sugar.
Compare and contrast the main pathophysiological basis of Type 1 and Type 2 Diabetes Mellitus (T1DM & T2DM)
TYPE 1:
due to pancreatic islet B cell destruction by autoimmne process causing proneness to keto-acidosis
TYPE 2:
more prevelent form resulting from insulin resistance with a defect in compensatory insulin secretion
Describe the genetic and immunological basis of T1DM referring to the role of “T cells” and “self tolerance”.
Type 1 diabetes is a disease in which tolerance to self-antigens, e.g insulin, is borken leading to expansion of autoreactive T cells that attack pancreatic B cells causing loss of insulin production
