Obesity Flashcards
(22 cards)
How does diet lead to excess fat storage (3)
Lipoprotein lipase hydrolysis TAG in chylomicrons to release FAs
They are stored in adipose tissue as TAG
Excess carbohydrates can also be synthesised into FAs and stored as TAG
Explain leptin deficient via gene mutation (3)
Ob/Ob mice are leptin deficient
Therefore unable to regulate food intake
Adiposity increases
Explain agouti and AgRP mutations (3)
Leads to increased AgRP expression
This inhibits alpha-MSH binding to MC4R
Which is an inhibitor of food intake
Why can’t gene mutations explain the reasons for the obesity epidemic
Similar gene mutations seen in humans are rare
Genetic predeposition for obesity (4)
It is thought that the human genome has evolved to favour energy storage in case of famine
This is known as the thrifty gene
Within the modern day obesogenic environment
This predisposes to obesity
Issues with lifestyle treatment for weight loss (2)
Although weight loss through lifestyle interventions have been shown improve metabolic health
It is not easily accomplished of maintained
What are the two types of bariatric surgery?
Malabsorptive
Restrictive
Explain malabsorptive surgery (2)
Shortens the gut
Which leads to a reduction in food absorption
Explain restrictive surgery (2)
Induces early satiety
And/or limits the rate of food intake
What have meta-analyses shown about bariatric surgery
Found that bariatric surgery reduces long term mortality in obese patients
Issues with bariatric surgery (3)
Safety risks
Costs of intervention
Limits use for large patient populations
What may be needed for long term prevention of obesity?
Combination of lifestyle and pharmacological interventions
Define obesity (2)
Condition of excessive fat accumulation in adipose tissue
To the extent that health may be impaired
Obesity essay plan (14)
Define obesity Overall cause of obesity Diet cause of obesity Genetic defects Genetic deposition Behavioural Metabolic syndrome Lifestyle Surgery Need for pharmacological intervention Sibutramine Rimonabant Orlistat Drug conclusion
Behavioural factors that contribute to obesity (5)
Frequent consumption of energy dense foods and drinks High fat diets Decreased PA Snacking Alcohol
Causes of obesity (3)
Ultimately obesity results from long term energy imbalance
Where energy intake exceed energy expenditure
However the causes of energy imbalance are complex
Leptin mechanism (6)
Secreted by adipocytes
Serum concentrations are proportional to amount of AT
Acts on hypothalamus to increase the expression of POMC and CART
Also inhibits the expression of AgRP and NPY
This decreases food intake
And increases EE
Potentials mechanisms underlying leptin resistance in obese individuals (2)
Desensitisation of receptors
And/or desensitisation or transporters into brain
Orlistat mechanism (5)
Synthetic derivative of lipststatin Potent inhibitor of pancreatic lipase Most fat digestion is mediated by pancreatic lipase Orlistat blocks the digestion of fat Thus reducing absorption of fat
Sibutramine mechanism (3)
NT reuptake inhibitor
Reuptake inhibitors enhance the signals of NTs
Sibutramine leads to a reduction in food intake by enhancing satiety
Rimonabant mechanism (3)
Rimonbant is an endocannabinoid CB1 receptor antagonist
Well known that cannabinoids increase food intake
Antagonism of the CB1R reduces food intake
Drug conclusions (3)
Although orlistat is not as effective as rimonabant or sibutramine in reducing body weight.
Orlistat is a good choice for the treatment of obesity
Because of its safety on cardiovascular events
