Obesity and Regulation of Appetite (DJ) Flashcards
BMI = formula
kg/m2
BMI for:
overweight
obese
morbidly obese
Overweight = 25-29.9
Obese < 30
Morbidly obese < 35
____ measures visceral fat (which is more toxic than fat in other places) which is correlated to in increase in morbidity
waist circumference
What waist circumferences in men and women are assc with obesity/inc morbidity
men >40 in
women >35 in
term for energy burned during rest
basal metabolic rate
term for energy spent digesting food
thermic effect of food
fidgeting/extra movement assc with daily activity that increase energy expenditure
NEAT
non-exercise activity thermogenesis
What we spend the most amt of energy doing during the day?
basal metabolic rate
greater than normal physical activity and thermic effect of food
basal metabolic rate increases with ___ and decreases with ____
Decreases with age and increases with obesity
What are the main strategies for effective weight control
Restriction of food intake and physical activity
Afferent and Efferent signals that maintain energy balance favors weight (loss or gain)
gain
What integrates afferent signals to determine appetite/efferent signals/energy intake
arcurate nucleus in hypothalamus
secreted in stomach → stimulates food intake (and GH)
ghrelin
Acts on Y1 and Y5 receptors to induce hunger
NPY
antagonizes MC4 receptor and reverses alpha MSH effect
AgRP
When is ghrelin expressed and when in NPY expressed?
both peak before meal and are present during fasting
What are the orexigenic substances expressed in the PVN?
NPY and AgRP
Decreases expression of NPY
leptin
binds MC4R and inhibits food intake
alpha-MSH
What activates alpha-MSH?
leptin
What is alpha-MSH derived from?
POMC (it is cleaved)
Co-localized in same neurons as POMC
Activated by leptin to inhibit food intake
CART
cocaine and amphetamine regulated transcript
Suppresses glucagon secretion and prolongs gastric emptying
glucagon-like-peptide-1
gut derived substance that promotes satiety? promotes hunger?
satiety = glucagon-like peptide hunger = ghrelin
Obese people are often “____ resistant” (not insulin)
leptin
centrally acting; levels increase in response to exercise, neuroglyucopenia, and enforced wakefulness –> hunger
Hypocretin
Serotonin, orexigenic or anorexigenic?
anorexigenic
TNF-alpha, orexigenic or anorexigenic?
anorexigenic (cachexia!!)
secreted from fat cells of insulin sensitive people but it is deficient in pts with obesity or insulin resistance
adiponectin
similar to insulin in that it increases in conc after meals and is anorexigenic
pancreatic polypeptide
released with feeding and serves as an anorectic/sateiy signal to intestinal cells
peptide YY
terminates meal rather than inhibits meal initiation
best known for stim of pancreatic enzyme secretion and gallbladder contraction but also involves regulation of portion size
Cholecystokinin
has been noted in obese pts and can be INDUCED BY OVERFEEDING
Overreactivity of endocannabinoid system (ECS)
ECS is normallt silent but it can be activated to …
increase appetite reduce pain and anxiety extinguish adverse memories inhibit motor behavior modulate temp, hormone release, smooth muscle tone
Centrally, what is happening when ECS is overreactive?
overactivation of CB1 receptor → DA released → increased motivation to eat
Peripherally, what does overreactive ECS cause?
dyslipidemia insulin resistance glc intolerance increased cardiometabolic risk Increased lipolysis in fat and liver Dec satiey feelings in GI Decreases glc uptake in skeletal muscle
selective antagonist to CB1 receptor. What effect would this molecule have on weight?
Rimbonaband, weight loss
What gene? 2 mutated alleles causes pts to never feel full
FTO
Affected are always hungry, never get signal to stop eating.
leptin deficiency
Feel the need to eat more frequently but still can get full
MC4 receptor mutation
Is leptin deficiency or MC4 receptor mutation more common
leptin deficiency
Causes decreased inter-prandial intervals
MC4 receptor mutation
