Obesity Part 2 Flashcards
What are the metabolic effects associated with obesity?
- Dyslipidimia (increase in serum TAGs especially VLDL)
- Glucose Intolerance
- Insulin Resistance
Tissues affected
- Liver
- Muscle
- Adipose
What is metabolic syndrome X?
Definition: a clustering of atherosclerotic and cardiovascular disease risk factors including: • Visceral adiposity (obesity), • insulin resistance • low levels of HDLs • a systemic proinflammatory state
What are the key componentsof metaboliccsyndrome X?
key components leading to metabolic syndrome include: • hypertension, • dyslipidemia, • insulin resistance, • chronic inflammation, • impaired fibrinolysis, • procoagulation and most telling • central obesity
What are the indicators of metabolic syndrome X?
Elevated fasting blood glucose= equal to or above 100 mg/dL
Elevated waist circumference equal to or above 40 inches men; 35 inchesvwomen
Elevated TAGs equal to or above 150 mg/dL
Reduced HDL cholesterol less than 40 mg/dL men; less than 50 mg/dL women
Elevated blood pressure more or equal to 130/80 mm
What are the normal insulin actions?
✓Stimulates lipogenesis,
✓increases amino acid uptake/protein synthesis
✓Increases glycogen storage
✓inhibits lipolysis,
✓Inhibits gluconeogenesis and
✓Inhibits glycogenolysis
What causes insulin resistance?
✓ Precedes the development of type II diabetes
✓ is commonly observed in obese and sedentary individuals.
What are the major metabolic changes associated with insulin resistance?
- Decreased lipoprotein lipase leading to increased plasma TAGs (Chylomicrons and VLDL)
- Increased lipolysis in adipose tissue and
- Increased fatty acids in plasma
- Increased glucose output by the liver
- Increased protein degradation in muscle
What are the effects of insulin resistance on lipid metabolism?
Triad in insulin resistance:
Increased VLDL, Increased LDL & Decreased HDL
Also: increased TAG & ApoB
Increased FFA
Increased ApoA-I
Explain insulin resistance
- Decreased number of insulin receptors?
• Decreased insulin receptor (tyrosine
kinase) activity?
- Complex changes in intracellular metabolic pathways resulting in tissue insensitivity to insulin?
- Insulin resistance (metabolic syndrome)
• Results in increased TAGs in circulation
(dyslipidemia)
- due to increase synthesis of VLDL by the liver and
- results in increased risk of atherosclerosis
What is the impact of insulin resistance to obesity?
There is a strong correlation between weight gain and the development of insulin resistance. i.e. weight gain increases insulin resistance and weight loss decreases insulin resistance
● A possible role for free fatty acids, leptin and adiponectin and some cytokines, all produced by adipocytes in the development of insulin resistance.
What is a microbiota? A microbiome?
- Microbiota: the collection of community of microbes.
- Microbiome: the full collection of genes of all the microbes in a community
Colonic fermentation of dietary fibers
What are useful methods for managing obesity?
- Diet and lifestyle:
• Decrease caloric intake: limit to 800-1000 kcal/day
• Increasephysicalactivity
• Improve the quality of food consumed
• less saturated fat ,
• increase intake of fruit and vegetable,
• increase fiber - Pharmacologic agents:
• Sibutramine: An Appetite suppressant
• Increases fullness- a feeling of satiety
• Orlistat: Gastric & Pancreatic lipase inhibitor,
• inhibits the digestion of dietary fats (TAG’s) and
• therefore reduces dietary TAG absorption. - Surgical management:
✓ Recommended for the morbidly obese (BMI>35).
✓ Intended to reduce food intake (smaller portions) and/or
✓ To reduce overall food absorption
✓ Used in conjunction with behavioral modifications in order to achieve long term weight loss objectives
What factors regulateobesity?
Regulation involves genetic, hormonal and environmental factors
