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Flashcards in Obesity Deck (17):

What is obesity defined as?

Abnormal/excessive fat accumulation sufficient to adversely affect health and reduce life expectancy


What BMI indicates obesity and morbidly obesity?

Obese >30
Morbidly obese >40


What is the limitation of BMI?

Body builders/people with a lot of muscle mass have a large BMI but are not obese
Have a thin waist so use waist circumference instead


What is the obesogenic environment?

- increased food intake: appetising, cheap, available, high energy density, socio-economic dependent access to healthy diet, food industry more interested in profit than public health
- less exercise: sedentary life style


What medications are related to weight issues?

Mood stabilisers
diabetes medicines
beta blocker
allergy relivers
drugs for migraines/seizures


What is the effect of insulin on weight?

insulin makes you fat
- inhibits breakdown and release from fat cells:
decreases lipolysis rate in adipose tissue
stimulates FA and TG synthesis
increases uptake of TG from blood into adipose tissue
decreases rate of FA oxidation in muscle and liver
lipohypertrophy: enlargement of fat cells local to where insulin is injected


What is syndromic monogenic obesity?

Exceptionally rare
Mental retardation, dysmorphic features, organ specific abnormalities, obesity
Prader-Willi, Fragile X are examples
1 mutation of 1 gene affecting a wide range of body functions/processes


What is Bardet-Biedl & Alstrom syndrome?

2 strong links to obesity:
- primary cilium has key role in differentiation of adipocytes -> defect in adipogenesis
- cilia mediate leptin receptor signalling


What is non-syndromic monogenic obesity?

1 mutation in any 1 of 12 genes
genes part of leptin-melanocortin pathway


How do adipocytes differentiate?

- ciliopathies (primary cilia dysfunction)
- mutations in PPARgamma2


What is PPARgamma2

Transcription factor that has a key role in adipocyte differentiation, targeted by TZD drugs


How is obesity a heritable trait?

- monogenic obesity
- polygenic obesity (227 genetic variants)
- epigenetic variation


What is the difference between apple shape and pear shaped individuals?

Apple shape = more visceral fat = higher risk of weight related health problem

Pear shape = less visceral fat = lower risk of weight related health problem


How can obesity lead to type 2 diabetes?

- chronic inflammation
- altered adipokine levels as high leptin levels
- breakdown of fat metabolism (lipid accumulation in tissue)
- breakdown of glucose metabolism regulation


What drugs treatments are there for obesity?

Orlistat - reduces amount of fat absorbed from food eaten by acting as a lipase inhibitor


What surgery can be done for obesity?

- weight management course first so taught about diet/nutrition/fitness/exercise
- laproscopically after conventional treatments failed
- if morbidly obese or BMI>35 and have obesity related complications
- restrictive procedures: restrict food passage with gastric banding/vertical banded gastroplasty and sleeve gastroplasty
- malabsorptive procedures: reduce ability to absorb nutrients
- restrictive plus malabsoprtive procedures (duodenal switch, Roux-en Y gastric bypass, intragastric balloon)


What are the main malabsoprtive surgical procedures for obesity?

Biliopancreatic diversion
Roux-en-Y gastric bypass

Can cause nutrient deficiencies, malnutrition, anastomotic leaks, dumping syndrome (rapid gastric emptying)