Obesity Flashcards
[Review] What do anabolic and catabolic mean?
Anabolic: synthesis (think “anabolic” steroids to build muscle)
Catabolic: breakdown (cats break things down)
[Review] What is BMR?
Basal metabolic rate: energy required for body maintenance.
What is the average BMR?
10kcal/lb.
What 2 factors decrease BMR?
- High adipose tissue.
2. Low muscle tissue.
Which 3 populations tend to have high adipose tissues (and subsequently, low BMR)?
Females (d/t estrogen).
Elderly.
Obese pts.
When would we see an increase in energy/BMR requirements?
Illness/infection.
Exercise.
What is the primary regulator of hunger?
The hypothalamus.
What is the primary hormone that stimulates hunger?
Ghrelin.
Where is ghrelin synthesized?
The stomach.
Besides ghrelin, what other hormone stimulates hunger?
Dopamine.
Which 2 chemical mediators stimulate the feeling of satiety?
CCK (cholecystokinin).
PPY (peptide YY).
Which hormone is considered the “opposite of ghrelin” because it stimulates satiety?
Leptin.
List 3 possible causes of low hunger drive.
- Sympathetic stimulation.
- Low iron.
- Meds.
What is the primary purpose of brown adipose tissue?
Thermogenesis for insulation.
Who has the highest % of BAT?
Infants.
Adults in _________ will have higher BAT.
Cold climates.
What are 3 purposes of white adipose tissue?
Energy.
Insulation.
Organ protection.
Breakdown of WAT for energy is stimulated by:
Lipase.
List the 3 substances synthesized by WAT.
Leptin.
Adiponectin.
Cytokines.
What are 4 functions of adiponectin?
- Suppress fatty acid influx into the liver.
- Increase fatty acid oxidation (breakdown).
- Enhances insulin function & glucose uptake.
- Anti-inflammatory.
What are 3 outcomes of high WAT r/t the 3 substances synthesized by it?
- Decreased leptin BBB distribution & receptor binding d/t resistance.
- Decreased adiponectin synthesis & secretion.
- Increased cytokine levels (r/t #2).
What is the major risk r/t leptin resistance?
Continuous weight gain: decreased stimulation of satiety = don’t feel full = overating.
What are 3 potential outcomes of decreased adiponectin synthesis?
- Increased fatty acid deposition (VAT, fatty liver, hyperlipidemia).
- Insulin resistance.
- Inflammation & risk of pro-inflammatory diseases.
Why is high WAT a risk factor for cardiac disease? (2)
- Dysfunctional angiogenesis.
2. Increased oxidative stress > atherosclerosis.
List 3 environmental factors that can lead to excess fat accumulation.
Inactivity.
Increased sugar intake.
Overeating.
What are 3 metabolic causes of excess fat accumulation?
- High estrogen/estradiol levels.
- Low testosterone levels.
- Impaired thyroid function.
The bacterial phylum of Firmicutes affects caloric absorption by:
Increasing digestion: more nutrients digested means more can be absorbed & stored.
The bacterial phylum of Bacteroides can:
Help decrease possible weight gain by decreasing absorption.
Why can obesity cause conditions such as gastric reflux, urinary incontinence and obstructive sleep apnea?
Increased abdominal girth = increased pressure on thoracic, abdominal and pelvic regions & less space for other organs (stomach, bladder, lungs) to expand.
Obesity carries a risk of drug-drug interactions with ________ drugs. Explain.
Lipophilic: fat attracts lipophilic drugs and stores them, so we will see increased half-life & decreased elimination = longer drug effects.
What are 4 risks of obesity in pregnant women?
- Gestational diabetes.
- Gestational HTN.
- Infertility.
- Large infant (& complicated delivery).
What BMI is considered overweight? What BMI is considered morbidly obese?
>25 = overweight. >40 = morbidly obese.
What waist circumferences in men and women would be indicators of obesity?
> 102 cm in men.
> 88 cm in women.
List the 5 risks factors of metabolic syndrome.
- Large waist circumference.
- Elevated BP.
- Low plasma HDL.
- Elevated plasma triglycerides.
- Elevated fasting plasma glucose.
Which 2 drug classes are helpful in treating obesity?
Lipase inhibitors.
Anorexiants.
What is the mechanism of action for lipase inhibitors?
Prevent hydrolysis of fats = decreased absorption & increased excretion.
Orlistat (Xenical) is pregnancy category:
X.
What is the mechanism of action for anorexiants?
Stimulating the SNS to increase BMR.
List 3 side effects of lipase inhibitors.
- Decreased lipophilic med/vitamin absorption.
- Fecal fat leakage.
- GI bloating & flatulence.
Lipase inhibitors are effective for up to ____ of ingested fats.
30%.
What is the prototype drug for lipase inhibitors?
Orlistat (Xenical).
What is the prototype drug for anorexiants? What is it a combo of?
Contrave: combo of Biproprion + Naltrexone.
What is bariatric surgery?
Creation of a gastric pouch to decrease stomach size and limit food intake/absorption.
What should be monitored in patients who have undergone bariatric surgery? Why?
Vitamin & electrolyte levels: since we cut some of the duodenum out (where vitamins & electrolyes are absorbed), pt may be at a deficit.
