Obesity Flashcards
What is obesity?
A condition of abnormal or excessive fat accumulation in adipose tissue, to the extent that health is impaired
What BMI is considered clinically obese?
> 30
Is obesity genetic?
- around 60-70%
- Identical twins tend to have similar BMIs, irrelevant of environment
- polygenomic
Mechanism of appetite?
- leptin (body fat)
- insulin (pancreas)
- hypothalamus
What is the most common gene associated with obesity?
MC4R
What social/environmental factors affect the risk of obesity?
- ability to play outside
- car use
- screen time
- education level / achievement
- poverty
- social deprivation
What drives obesity?
The environment either heightens or reduces the impact of genetics on the risk of obesity
What co-morbidities are associated with obesity?
- depression
- sleep apnoea
- stroke
- myocardial infarction
- hypertension
- diabetes
- peripheral vascular disease
- gout
- osteoarthritis
- bowel cancer
- infertility
- gallbladder disease
Impact of obesity of cancer?
Incidence of cancers increases in those with obesity
What does an BMI above 35 mean for your life expectancy?
2 x the risk of death of those of a healthy BMI
Only effective example of reduction in obesity at a national level?
- economy collapse, fuel and food shortages
How do we treat obesity?
- determine degree of obesity
- assess lifestyle, co-morbidities and willingness to change
- management, lifestyle changes, drug treatment
- consider referral to specialist
- possibly: bariatric surgery
Why do weight rebounds happen?
Hypothalamus thinks: starvation, therefore encourages you to regain +more (increases appetite)
What does leptin deficient mean?
- insatiable hunger
- body is in survival mode, irrelevant of what is seen in the mirror
- almost impossible to lose weight
- infertility
- stunted linear growth
- decreased body temperature
- decreased energy expenditure
- decreased immune function
How to address health issues caused by diabetes?
- identify how difficult losing weight is
What is the impact of visceral fat?
- Visceral fat (fat at the waist), feeds the most into co-morbidities
- worse in men
What dietary recommendations should be made?
- 3 portions of fruit+veg (minimum)
- more fruit+veg the better
What drugs are used to treat obesity?
- Orlistat
- Gastric and pancreatic lipase inhibitor
- prevents fat absorption by 30%
- less than 3% change in weight
- low adherence (due to uncomfortable side effects)
(have to be safe, because used as a preventative measure)
-GLP1 agonists
What about Bariatric surgery?
criteria
BMI>40 BMI35-40 and other comorbidities BMI30-34.9 (T2DM) BMI>50 : first line option - non-surgical failed to achieve/maintain clinically beneficial weight-loss (at least 6 months) - receive intensive specialist treatment - fit for anaesthesia and surgery - commit to long-term follow up
What are the 3 types of Bariatric surgery?
- Gastric Bypass
- Gastric Band
- Sleeve Gastrectomy
What is the effectiveness of Bariatric surgery?
- most effective: Gastric Bypass (25% body weight - long term)
- least effective: Gastric Band
Impact of treatment of leptin deficiency?
- puberty
- increased educational treatment
- lose weight
Risks of bariatric surgery?
- risk of gambling
- risk of risky sex
What is the process of a Gastric Bypass surgery?
the top part of the stomach is joined to the small intestine, feel fuller faster, less calories consumed
What is the process involved in a Gastric Band?
band is placed around the stomach, therefore less food is required to feel hungry
What is the process involved in a Sleeve Gastrectomy?
removal of some of the stomach, therefore unable to eat as much as you could before - feel full sooner
What can leptin administration restore in deficient children?
FSH and LH pulsatility
What can leptin administration restore in deficient women?
Periods (due to LH pulsatility being resotred)
What is leptin?
An anti-starvation hormone NOT an anti-obesity hormone
What is semaglutide?
Long-acting glucagon-like peptide-1 (GLP-1) receptor agonist.
What is liraglutide/saxenda?
- Long-acting glucagon-like peptide-1 receptor agonist
- Daily injection.
- Double the dose used for T2DM.
- 4-5% weight loss
What is tirzepatide?
Long-acting glucagon-like peptide-1 (GLP-1) receptor and glucose-dependent insulinotropic Polypeptide (GIP) receptor co-agonist.
What is cagrilinitide?
Long-acting amylin analogue given in combination with semaglutide.
