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 classification is given for obesity?
BMI > 30
What is the problem with BMI?
BMI does not account for muscle mass
What is a GWAS and what has it shown for obesity?
Genome Wide Association Study - shows there are multiple genes involved in BMI, Waist:Hip Ratio, Body Fat, Birthweight, Satiety upon Food Intake (Leptin and GLP-1)
What are some of the driving factors of obesity?
Food intake (cheap, high calorie high fat high salt&sugar food widely available), Sedentary lifestyle (cars, fewer playgrounds, screen time), Income, Education
What are some comorbidities associated with obesity?
T2DM,
CVD,
Stroke,
Cancer,
Hypertension,
Osteoarthritis,
Sleep Apnoea,
Depression
Describe the relationship between mortality and BMI
Lowest risk of mortality is in a healthy BMI, there is a slightly higher risk at lower BMIs, but there is an exponential increase as BMI reaches overweight and obese levels
How would you assess the patient for a management plan for obesity?
Assess the patient’s current lifestyle, comorbidities and willingness to cooperate, from there you can suggest lifestyle changes, drugs or surgery
At what stage would you consider drugs for obesity control?
At any stage where comorbidities are present, always when severe or morbidly obese
When would you consider surgery for obesity control?
Morbidly obese or severely obese with comorbidities
Obesity and the hypothalamus
Responds to signals from the periphery e.g. the gut
Causes appetite suppression via short term signals
long term signals from adipose tissue indicate levels of fat stores
Where is leptin produced and where does it act?
Adipose tissue, acts on the brain
What is the general function of leptin?
Induces satiety feeling to stop eating -> anti-starvation hormone by telling the brain it has enough fat to survive
How can leptin deficiency present?
Infertility,
stunted linear growth,
obesity,
decrease body temperature and energy expenditure, decreased immune function,
Hyperphagia (really hungry)
mode of starvation
What are 6 physiological functions of leptin?
Regulation of appetite,
increases blood pressure,
regulates thyroid hormone synthesis,
decreases insulin secretion,
increases heart rate,
regulates menstrual cycle
How can you treat leptin deficiency and what does this do?
Administer recombinant leptin therapy - reduces weight and restores FSH & LH pulsatility
Where else can leptin administration be used?
Restoring LH pulsatility in women with amenorrhea
Can you use leptin to treat T2DM
Leptin resistance
High leptin has little effect as it signals to the CNS that the system has sufficient fat reserves
Medication for obesity
derivatives of endogenous lipostatin
gastric and pancreatic lipase inhibitor
reduces dietary fat absorption by around 30%
Orlistat
lipase inhibitor
3% weight reduction
GI problems, steatorrhea
What are the effects of GLP-1?
Low appetite, high satiety, high insulin, more sodium excretion
What is a long acting GLP-1, and how effective is it?
Liraglutide, daily injection, 4-5% weight loss
GI side effects
When can bariatric surgery be recommended?
BMI > 40 or > 35 with comorbidities
Non-surgical measures have failed, fit for surgery, will commit to follow-up plan
What are the three types of bariatric surgery?
Gastric bypass (top of stomach joined to small intestine - do not absorb as much),
Gastric band (band around stomach constricting, less food needed to feel full),
Sleeve gastrectomy (some stomach is removed vertically, cannot eat as much to feel full)
