Obesity Flashcards
Define overweight and obesity by BMI percentile (WHO criteria)
- AGE 5-19:
- Overweight: >85th percentile
- Obese: 97th percentile
- AGE <2:
- Overweight = Weight >97th
- Obese = Weight >99.9th
- AGE 2-5:
- Overweight = BMI >97th
- Obese = BMI > 99.9th
- Overweight = BMI >97th
- ADULTS
- Overweight = BMI 25-29.9
- Obese = BMI >30
What is the prevalence of overweight and obesity in Canadian children?
- Overweight 20%
- Obese 12%
- Note: age 5-17
What cells produce leptin? What does it signal?
Adipocytes
Satiety signal (long-term)
List 3 clinical features of leptin deficiency
- Severe, early onset obesity
- Decreased immune function
- Hypogonadotropic hypogonadism
*Think physiologic signs of starvation
What cells produce Ghrelin? What does it signal?
- Gastric X/A-like cells
- Stimulated by fasting
- Stimulates hunger/food intake (decreases after a meal, short-term effect)
- Acts on hypothalamus
What cells produce cholecystokinin? What does it signal?
- Proximal intestinal I cells
- Promotes meal termination, reduces meal size, stimulated by duodenal presence of fat and protein (short-term effect)
What cells produce Peptide YY3-36 (PYY)? What does it signal?
- Distal intestinal L cells (ileum and colon)
- Acts on hypothalamus
- Stimulated by fat in the lumen, reduces appetite and food intake
What cells produce Glucagon-like peptide 1 (GLP1)? What does it signal?
- Distal intestinal L cells (ileum and colon)
- Stimulated by presence of nutrients in the lumen
- Signals short-term inhibition of food intake. half life is 2 minutes
- Degraded by DPP-4
What cells produce pancreatic polypeptide? What does it signal?
- Pancreatic F cells
- Released in proportion to calories ingested
- Reduces appetite and food intake
Describe the neurons in the arcuate nucleus of hypothalamus that impact obesity signaling
List 5 syndromes associated with obesity
- Prader Willi: obesity, hypotonia, MR, short stature, hypogonadotropic hypogonadism
- Barder-Biedl: hypogonadism, pigmentary retinopathy, polydactyly, MR
- Alstrom: myocardiopathy, sensory deficit (retinopathy, deafness), obesity, dyslipidemia, diabetes
- Borjeson-Forssman-Lehman: severe MR, epilepsy, hypogonadism, facial dysmorphism
- Cohen: MR, characteristic facies
- Carpenter: acrocephalosyndactyly, polydactyly, MR
List 5 monogenic causes of obesity
- Leptin deficiency
- Leptin receptor deficiency
- POMC
- PC-1
- NTRK2
- SIM1
- MC4R
List 5 treatment modalities for hirsutism
- Cosmetic (laser hair removal, waxing, electrolysis, shaving)
- Topical (eflornithine hydrochloride cream- Vaniqa)
- OCP
- Anti-androgen (cyproterone, spironolactone)
- Lifestyle (weight management)
- Metformin
List 3 neuroendocrine appetite stimulants
- Ghrelin
- NPY (localized in arcuate nucleus adjacent to POMC)
- AgRP (localized in arcuate nucleus adjacent to POMC)
- Endocannabinoids (stimulate food intake via CB1 receptor)
- Orexins A and B (stimulate NPY releat)
List 2 neuroendocrine appetite suppressants
- Leptin
- Peptide YY 336
- Insulin
- GLP-1
- Cholecystokinin
- POMC
- Alpha-MSH
- CART (hypothalamic neuropeptide)
What is the definition of metabolic syndrome
- NCEP ATP III (Adult): 3 or more of
- High fasting glucose (>5.6)
- High triglycerides (>1.7)
- Low HDL (<1.0 in males, <1.3 in females)
- High blood pressure (>130/85)
- High waist circumference (>40 in males, >35 in females)
- Modified ATP III for pediatrics: 3 or more criteria but no waist circumference
- IDF: 2 or more criteria
List 8 additional features of metabolic syndrome (aside from TG, HDL, WC, BP, FBG)
- Increased FFAs
- Increased VLDL
- Increased small dense LDL
- Increased ApoB
- Increased inflammatory cytokines (IL-6)
- Increased CRP
- Increased plasminogen activator inhibitor (PAI-1)
- Fatty liver disease, PCOS, sleep-disordered breathing?
List 5 features of PWS on history?
5 physical exam features?
- History
- Prenatal: reduced fetal movement, polyhydramnios, breech
- Neonatal hypotonia, weak cry
- Feeding difficulty, poor suck, may have FTT
- Delayed motor skills
- Hyperphagia (onset 2-8 years)
- Behavioural and learning difficulties
- Mild/mod cognitive impairment
- Delayed puberty, premature adrenarche
- Physical exam
- BMI >95th percentile with decreased lean body mass
- Depigmentation relative to family
- Cryptorchidism, small testes
- Micropenis
- Almond shaped eyes
- Small hands and feet
- Strabismus
- Scoliosis
- Short stature
List 4 advantages and 3 disadvantages to using BMI as a surrogate marker for adiposity
- Advantages
- More accurate than weight alone
- Correlates with body fat and CVD risk
- Norms are established in children and adults
- Easy to measure and track
- Cheap and non-invasive
- Disadvantages
- Does not differentiate weight of muscle vs fat
- Does not differentiate central vs generalized obesity
- Not useful in pregnancy
- Not useful in children <age>
</age><li>Not useful for extremes of height</li>
List 10 things to assess at a first clinic visit for obesity management
- History
- Readiness to change, what has she tried in the past
- Dietary history
- Screens
- Physical activity
- Sleep
- Mental health review
- Review of systems: r/o hypothyroidism, Cushing, PCOS, OSA, DM2
- Family history of obesity, CVD, type 2 diabetes
- Physical exam
- BMI
- Waist circumference
- Acanthosis nigricans
- Blood pressure
- Fundoscopy
- Signs of dyslipidemia
- Labs
- OGTT
- Lipid profile
- LFTs
- Thyroid function
- Urinalysis
*
List 2 anti-obesity medications approved in Canada and their mechanism of action
- Orlistat (approved for >12 yo). Prevents absorption of fat from intestine by inhibiting pancreatic lipase.
- Metformin. Mechanism is unclear, reduces hepatic glucose production, increases peripheral insulin sensitivity.
- Saxenda (liraglutide): GLP1 agonist, approved in adults.
