Endocrine Aspects of Bariatric Surgery

Question 1

Name 5 orexigenic hormones.

Answer 1

1) NPY
2) Orexin A & B
3) MCH
4) Agouti-related protein
5) Norepinephrine

Question 2

Name 7 anorexigenic hormones.

Answer 2

1) CRH
2) aMSH
3) CART
4) Bombesin
5) Cholecystokinin (CCK)
6) Serotonin
7) Leptin (adipocytokine)

Question 3

Which 5 signals are integrated by the hypothalamus to modulate eating behavior?

Answer 3

1) Hedonic input (pleasure of eating)
2) GI hormones
3) Neuronal signals
4) Pacreatic hormones
5) Adipocytokines

Question 4

What are the typical leptin levels like in obese people? How can this be explained?

Answer 4

Leptin is usually elevated, despite being anorexigenic; high leptin leads to leptin resistance so obese people do not have suppressed appetite as a result of elevated leptin

Question 5

What happens to leptin levels after someone loses weight?

Answer 5

Leptin levels drop (part of trying to maintain adipose tissue homeostasis), so hunger is stimulated.

Question 6

What are the recommendations for consideration for bariatric surgery?

Answer 6

BMI > 35 AND complications/comorbidities (esp DMII, esp if hard to control with lifestyle & meds)

Question 7

What are the 3 types of restrictive bariatric surgery? Which is most common?

Answer 7

1) Vertical banded gastroplasty
2) Sleeve Gastrectomy
3) Laparoscopic adjustable gastric banding

Lap banding is most common

Question 8

What are 2 types of malabsorptive bariatric surgery?

Answer 8

1) Duodenal switch/biliopancreatic diversion

2) Duodenal sleeve

Question 9

What is the combined restrictive/malabsorptive surgery?

Answer 9

Roux-en-Y bypass

Question 10

What are some complicating factors that accompany LapBand surgery?

Answer 10

1) Usually need to be adjusted surgically a few times to find “sweet spot” of restriction
2) 40% revision rate since many patients continue to overeat
3) Many patients avoid diet restrictions by blending their food or eating many small meals throughout the day

Question 11

What are the major complications that accompany malabsorptive surgeries?

Answer 11

1) Steatorrhea
2) Fat-soluble micronutrient deficiencies
3) Flatulence - due to microorganisms breaking down nutrients in the gut

Question 12

Which vitamin deficiencies are most common for roux-en Y gastric bypass?

Answer 12

1) Iron
2) B12
3) Vitamin D

Question 13

How does gastric bypass lead to weight loss? What is one piece of evidence for this?

Answer 13

Metabolically starves patients; they begin to produce ketone bodies