obesity and the regulation of appetite Flashcards
leptin made where
adipose tissue
obesity
biological response to modern environment where body regulates to. a set point to high
what are the two types of adipose tissue
and the two types of white adipose tissue
brown and beige adipose e- white contaisn white adipocytes and is most common type ( large vacuole that stores lipids produced via lipogenesis and from food consumed)
white
Subcutaneous white adipose tissue SWAT found under the skin throughout the body and has several functions
and acts a layer of insulation
visceral white adipose tissue VWAT is located around the internal organs and is the main type of adipose tissue used for energy storage
brown adipose tissue BAT contains brown adipocytes
many small vacuoles holding lipids - abundant in mitochondria contributing to brown appearance. main function being to oxidise lipids for heat production through a process known as non-shivering thermogenesis
beige adipose tissue if found scattered throughout SWAT deposits. ( beige or brite ( white undergo browning )
what can WAT browning be intimated by
atherogenic stimulus such as prolonged exposure to the cold
what type of adipocytes have the ability to revert back to white adipocyte once the body reaches normal temp again
beige adipocytes
how does fat increases cancer risk
too much body fat can trigger inflammation - producing too much insulin from beta cells and oestrogen from the fat cells - these all causes cells divide more than usual - potentially increasing the risk of amber
being overweight can block blood vessels in brain leading to
stroke or vascular dementia
visceral fat is the fat you need to watch as this causes
raise in blood cholesterol
increase in blood pressure
increase risk of type 2 diabetes
apple shaped - visceral round abdominal - pear shaped is SC around bottom
NICE guidance for obesity treatment
encourage life style change and integrate activities
then identified by bmi - Asians and africans more at risk
treatment then includes
morlistate
liragltuide
stages of obesity vmi
healthy is 18.5-24.9 overweight 25-29.9 obesity I - 30-34.9 Obesity II - 35-39.9 Obesity III- 40 or more
short term energy storage
liver as glycogen
long term energy storage
white adipose tissue ( triglyceride
atypical spill over storage
liver
muscle and bone
brown adipose tissue is more metabolically active than white adipose tissue and is richly vascularised and packed with mitochondria
where do you find brown adipose tissue in neonates
shoulder and sternum and between shoulder blades and kidney area
function of WAT
Triglyceride storage
Heat insulation
Mechanical cushion
Adipokine production
reasons for obesity causes cancer
Proposed molecular mechanisms:
Chronic low grade inflammation
Adipose production of oestrogen (altered aromatase)
Increased levels of insulin and bioavailable insulin like-growth factor (IGF)
Oxidative stress
genetic causes of obesity
polymorphisms in different genes and interaction between that and the environment.
melanocortin-4 receptor
POMC mutuations
BDNF mutations
leptin mutations
prayer will syndrome - multiple defects
strategies to reduced bodyweight
Lifestyle interventions
Diet & exercise
Sleep
Pharmacological interventions (see BNF) Orlistat: Lipase inhibitor. Prevents fat absorption. Used in combination with lifestyle interventions
Liraglutide: GLP-1 agonist.
Naltrexone–bupropion (off label): Bupropion = Norepinephrine-dopamine reuptake inhibitor and nicotinic acetylcholine receptor antagonist; Naltrexone = Opioid receptor antagonist
Bariatric Surgery (see LSRC Obesity Surgery)
Gastric bypass
Gastric band
Sleeve gastrectomy
which cell types are found in WAT
adipocytes
fibroblasts
endothelia cells
immune cells
reason for why obesity increase risk of cancer
causes oxidative stress
increases production of growth factors
results in chronic tissue inflammation
