obesity

Question 1

definition of obesity

Answer 1

BMI >30kg/m2

higher waist to hip ratio - indicating central fat distribution

Question 2

epidemiology of obesity

Answer 2

more common in men

Question 3

risks of obesity

Answer 3

t2dm

IHS

dyslipidaemia

htn

OA

cancer - breast and bowel

Question 4

RF for obesity

Answer 4

genetic - prader-willi syndrome, lawrence-moon syndrome

hypothyroidism

cushing’s syndrome

hypothalamic damage eg tumour or trauma = damage to satiety regions

corticosteroid therapy

Question 5

aetiology of obesity

Answer 5

calorie intake > expenditure

genetic predispostion

behavioural dynamics

hormonal disturbances

cultural influences

env circumstances

Question 6

behavioural factors that -> obesity

Answer 6

trend to larger portion size

sedentary lifestyle

poor diet

eating disorder

mental illness

Question 7

how does culture = obesitu

Answer 7

cultural practices, beliefs about beauty and body image, cuisines, eating habits, and lifestyles contribute to obesity, both within the US and in other countries

Question 8

how does env = obesity

Answer 8

low socioeconomic level

adverse nutrient environment in utero

Question 9

hormonal causes of obesity

Answer 9

hypothyroidism

hypercortisolism

insulinoma

Question 10

signs and sx of obesity

Answer 10

BMI - weight and height

Question 11

Ix for obesity

Answer 11

BMI 30.0 to 39.9 kg/m²; class III obesity: BMI ≥40.0 kg/m²

FBC - normal, maybe anaemia

serum transaminases - normal, may be elevated if liver dysfunction

TFT

ECG

abdo US - normal/fatty liver

polysomnography (sleep study) - for sleep apnoea

Question 12

pathology of obesity

Answer 12

appetite - 2 way communication system between the CNS (hypothalamus) nad peripheral tissues (gut and adipose)

hypothalamus - process the hormones eg leptin, peripheral nerve input eg gastric distension sending -ve feedback to hypothalamus throigh vagal afferents and input from cerebral cortex. 2 populations of neurons in arcuate nucleus. organise info and send signals to CNS. regulates appetite

leptin - secreted by adipose when substrate is plentiful - satiety signal - enhance secretion of appetite inhibitors: pro-hormone pro-opiomelanocortin, and cocaine- and amfetamine-regulated transcript peptide. Inhibit release of neuropeptide Y, agouti-related protein, and orexin A and B.

obese = leptin resistance

ghrelin - secreted by the stomach - increase appetite

endocannabinoids - orexigenic

T3 - increase appetite

peptide YY - decrease appetite

GLP1 - stim insulin

oxyntomodulin - inhibit food intake

cholecystokinin - inhibit appetite

pancreatic polypeptide - reduce appetite

insulin - anorectic

hypoglycaemia = food seeking