Obesity

Question 1

chronic condition defined as an excess of body fat or adipose tissue that causes disease.

Answer 1

Obesity

Question 2

A normal BMI

Answer 2

18.5 and 24.9 kg/m2

Question 3

overweight

Answer 3

BMI between 25 and 29.9 kg/m2

Question 4

class I obesity

Answer 4

BMI of 30 to 34.9 kg/m2

Question 5

class II obesity

Answer 5

BMI of 35 to 39.9 kg/m2

Question 6

class III obesity

Answer 6

BMI greater than 40 kg/m2

Question 7

Complications of obesity

Answer 7

type 2
diabetes, stroke, heart disease, NAFLD, and several types of
cancer, all of which are considered obesity-related causes of
preventable death globally

Question 8

Dietary Factors

Answer 8

These studies favor a high-protein, low-carbohydrate diet for
avoidance of excess weight gain.

high-protein diets
may be favorable are increased satiety, increased thermic effect
of food, and improved body composition.

Question 9

Medication-Induced Weight Gain

Answer 9

antipsychotics (e.g., olanzapine, clonazapine),
antidepressants (e.g., the SSRI, paroxetine), anti-epileptics (e.g., valproate, gabapentin), insulin and insulin secretagogues (e.g., thiazolidinediones),
glucocorticoids,
progestational hormones and implants,
oral contraceptives,
beta-blockers

Question 10

Smoking

Answer 10

first, smoking is thermogenic—that is, the metabolic rate
during the act of smoking is higher than when the subject is not
smoking;

second, smoking reduces hunger and changes taste perception so smokers tend to eat less.

Question 11

Genetics

Answer 11

The melanocortin-4 receptor (MC4R) gene, leptin gene, pro-opiomelanocortin (POMC) gene, and agouti gene all have significant effects on body fat and fat stores.

Question 12

Obesity, mental retardation, brachymetaphalangism, short stature

Missense, frameshift, nonsense, splice-site, deletions, insertions in GNAS1/GNAS. Autosomal dominant

Answer 12

Albright hereditary osteodystrophy/ pseudohypoparathyroidism type Ia

Question 13

Childhood obesity, insulin resistance and type 2 diabetes mellitus, blindness, hearing impairment

Frameshift, nonsense, missense in ALMS1. Autosomal recessive

Answer 13

Alström syndrome

Question 14

Obesity, retinitis pigmentosa, renal malformation, polydactyly, mental retardation, hypogonadism

Missense, nonsense, splice-site and frame-shift mutations in BBS1, BBS2. Autosomal recessive

Answer 14

Bardet-Biedl syndrome/Laurence- Moon-Bardet-Biedl syndrome

Question 15

Obesity, umbilical hernia, soft tissue syndactyly, congenital heart disease, mental retardation, hypogenitalism

Truncating, missense, nonsense mutations of RAB23. Autosomal recessive

Answer 15

Carpenter syndrome/ acrocephalopolysyndactyly type II

Question 16

Obesity and hyperphagia, failure to thrive, hypotonia, genital hypoplasia, mental retardation, small hands and feet

Deletions, mutations, loss of paternal allele MKRN3/ ZNF127/MAGEL2. Autosomal dominant, x-linked

Answer 16

Prader-Willi syndrome/Prader- Labhart-Willi

Question 17

Leptin

Answer 17

Absence of leptin or an ineffective leptin receptor is associated with severe obesity

Leptin has the dual effect of reducing food
intake and increasing energy expenditure, both of which favor
loss of body fat.

Treatment of leptin-deficient children with
leptin decreased their body weight and hunger, indicating
the importance of leptin in normal subjects.

Question 18

PATHOPHYSIOLOGY OF OBESITY

Answer 18

One body of neurons expresses the orexigenic peptides neuropeptide Y and agouti-related peptide, each of which function to increase food intake and reduce energy expenditure.

express POMC, and cocaine- and amphetamine-regulated transcript, which are anorexigenic peptides that lead to a reduction in appetite and increase in energy expenditure by activation of downstream pathways, such as activation of MC4R in the para- ventricular nucleus of the hypothalamus.

Question 19

Damage to POMC neurons

Answer 19

Damage to POMC neurons and concomitant inflammation has been associated with diet-induced obesity and resistance to weight-regulating hormones including leptin and insulin

Question 20

reduce food intake

Answer 20

Intestinal peptides, including glucagon-like peptide (GLP),

CCK, pancreatic polypeptide, and polypeptide YY

Question 21

stimulates food intake

Answer 21

ghrelin, a small peptide produced in the stomach

Question 22

an enzyme that is activated or inhibited in relation to the ratio
of adenosine monophosphate to adenosine triphosphate and is
thought to be the underlying central point in the control system of food intake

Answer 22

Oxidation of fatty

acids modulates activity of 5′-adenosine monophosphate kinase

Question 23

Waist circumference

Answer 23

Waist circumference should be measured with the proper technique at the level directly above the iliac crests, especially in patients with a BMI greater than 25 to 35 kg/m2 who will require further risk stratification

Question 24

indicative of insulin resistance;

Answer 24

presence of acanthosis nigricans and skin tags
violaceous striae and dorsocervical fat pads indicative of hypercortisolism; and thyromegaly and delayed reflexes as signs of hypothyroidism.

Question 25

Lipid Derangements

Answer 25

dyslipidemia, characterized by low HDL cholesterol and high
TG levels, is more common in obese than in non-obese individuals, particularly those with central adiposity.

Obesity also increases the risk of heart failure and atrial fibrillation

Question 26

Obesity-related

glomerulopathy

Answer 26

a BMI ≥30 kg/m2 and the
presence of glomerulomegaly with or without focal segmental
glomerulosclerosis on kidney biopsy

Question 27

Gallbladder Disease

Answer 27

increased total cholesterol levels
seen in patients with obesity are excreted in the bile, where high
cholesterol concentrations relative to bile acids and phospholipids may increase the likelihood of precipitation of cholesterol
gallstones in the gallbladder.

Question 28

Gallbladder Disease

Answer 28

During weight loss, the likelihood
of gallstone formation paradoxically increases because the flux of
cholesterol mobilized from fat is increased throughout the biliary
system

Question 29

Gastroesophageal Reflux Disease (GERD)

Answer 29

erosive esophagitis and esophageal adenocarcinoma were also more common in obesity, with prevalence rates of 12.5% for BMI less than 25 kg/m2 compared with 26.9% for BMI greater than 30 kg/m for erosive esophagitis

Question 30

Cancer

Answer 30

Men with obesity have an increased risk for
colon, rectal, and prostate cancers

women with obesity experience more cancers of the reproductive system and
gallbladder

greater risk of endometrial cancer in overweight
women is the increased production of estrogens by aromatization in adipose tissue, which is related to the degree of excess
body fat and accounts for a major source of estrogen production in postmenopausal women.

Question 31

Breast cancer

Answer 31

Breast cancer is not only
related to total body fat but may also have a more important
relationship to central body fat, which may help explain why
breast cancer risk is increased at age 75 in women in the highest quartile BMI. Increased visceral fat as measured by CT
shows an important relationship to the risk of breast cancer.

Question 32

Obstructive Sleep Apnea

Answer 32

Increased neck circumference (≥17 inches in men and ≥16 in
women), enlarged floppy uvula, and tonsillar hypertrophy are
predictors of obstructive sleep apnea (OSA).

Question 33

Acanthosis nigricans refers

Answer 33

to a deepening pigmentation in the folds of the neck, axillae,
knuckles, and extensor surfaces that occurs in many overweight
individuals

Question 34

Low-Fat Diets (LFDs)

Answer 34

dietary guidelines recommend a reduction in the daily intake of fat to 30% of energy intake or less.

In a met-analysis of trials comparing LFDs (typically <25% of total calories from fat) with a control group consuming a regular diet (30% to 40% of total calories),

Question 35

Low-Carbohydrate Diets (LCDs)

Answer 35

Paleo diet is a variation of an LCD as it removes grains, in addition to dairy, from the diet.

Question 36

Pharmacotherapy

Answer 36

The National Heart, Lung, and Blood Institute of the National Institutes of Health recommends that for individuals who fail to respond to lifestyle interventions after 6 months of treatment, have a BMI of greater than 30 kg/m2, or a BMI of greater than 27 kg/m2 with a weight-induced comorbidity, weight-loss medication may be added to their treatment plan

Question 37

Phentermine/Topiramate

Answer 37

Low-dose, controlled-release phentermine plus topiramate (as 1 capsule)

Phentermine is an adrenergic agonist that promotes weight loss by activation of the sympathetic nervous system with a subsequent decrease in food intake and increased resting energy expenditure

Question 38

Lorcaserin

Answer 38

selective serotonin 2C receptor agonist, was approved by the FDA in 2012 as a long-term treatment for obesity.

selectively activates the central serotonin 2C receptor over the 2A and 2B receptors and reduces appetite by binding to the 5HT-2C receptors on anorexigenic POMC neurons in the hypothalamus.

The recommended dose of lorcaserin is 10 mg twice daily with or without food. There is also a new 20 mg extended release tablet to be taken once daily.

Question 39

Bupropion/Naltrexone

Answer 39

Bupropion’s primary mechanism of action is as a reuptake inhibitor of dopamine and norepinephrine.

Inhibiting reuptake of dopamine and/or norepinephrine modulates the “reward pathway” that various foods can stimulate.

Naltrexone is a pure opioid antagonist that blocks an opioid pathway that may slow weight loss.

Question 40

Orlistat

Answer 40

inhibiting GI lipases, thereby decreasing the absorption of fat from the GI tract.

Question 41

EVALUATION AND SELECTION OF BARIATRIC

SURGERY CANDIDATES

Answer 41

a BMI of 40 kg/ m2 or greater or a BMI of 35 kg/m2 or greater with obesity- related co-morbidities and at least 6 months of documented medically supervised weight loss attempts.

Question 42

Contraindications to bariatric surgery

Answer 42

psychiatric conditions such as schizophrenia, severe bipolar disorder, active substance abuse, recent major depression with hospitalization or suicide attempts, and developmental delay.

Age is not an absolute contraindication in patients with severe co-morbidities and bariatric surgery is performed in patients older than age 65 or younger than age 18

Question 43

recommended by the European Association for Endoscopic Surgery

Answer 43

A preoperative EGD is recommended by the European Association for Endoscopic Surgery to detect and treat any upper GI lesions that may cause postoperative complications or influence the decision of which type of bariatric surgery should be performed

Question 44

Gastric Bypass

Answer 44

There are many variations of laparoscopic RYGB techniques, but essential components include construction of a gastric pouch, attaching the pouch to the jejunum, and re-routing digestive enzymes such that they do not contact food until it reaches the jejunojejunostomy

Prophylactic subcutaneous heparin (5000 units), sequential compression devices, and cefoxitin (2 g IV) should be administered prior to incision

Question 45

Gastric Bypass

Answer 45

The greater omentum is elevated, and the ligament of Treitz is identified.

The jejunum is divided into biliopancreatic and Roux limbs at 20 cm distal to the ligament of Treitz.

Next, the jejunojejunostomy is performed after a 75 to 150 cm Roux limb is passed toward the proximal gastric pouch, either through the transverse mesocolon (retrocolic) or in front of the colon (antecolic); the retrocolic method may either take a retrogastric or antegastric route.

Any mesenteric defects between loops of bowel are potential hernia sites and, therefore, are closed with permanent running suture.

The gastric pouch should be between 15 mL and 30 mL in size and is constructed based on the size of the lesser gastric curve. Finally, the gastrojejunostomy is constructed either through circular-stapled, linear-stapled, or hand- sewn techniques, and a surgical drain may be placed.

Question 46

Sleeve Gastrectomy

Answer 46

removing about 80% of the stomach, with a resultant remain- ing sleeve that is lesser curve-based and is 28 to 32 French (Fr) in diameter.

The patient is given a PPI for 6 months postoperatively as well as multivitamins to be taken for life.

Diet is slowly advanced over 8 weeks as an outpatient from full liquids to pureed food to soft food and finally to a regular diet.

Question 47

Complications

Answer 47

Complications can be divided into 3 categories: intraoperative, early postoperative (within 30 days of surgery), and late postoperative (>30 days after surgery).

Question 48

Early postoperative complications

Answer 48

Early postoperative complications are anastomotic leaks, pulmonary and cardiovascular complications including DVT and PE, and mortality.

Question 49

Late postoperative complications

Answer 49

Late postoperative complications include anastomotic stricture, gallstone formation, nutritional deficiencies, bowel obstruction, intussusception, marginal ulcers or ulcers in the remnant stomach and duodenum, fistula, dumping syndrome, and hypoglycemia.

Cholelithiasis develops in up to 38% of patients after RYGB.

Question 50

Gallstone formation

Answer 50

Gallstone formation occurs secondary to a combination of vagus nerve damage, altered enteric nerve stimulation, decreased gallbladder emptying, and changes in calcium concentration and the bile salt/ cholesterol ratio

To reduce the incidence of cholelithiasis, a 6-month course of ursodiol is recommended for patients whose gallbladder is not removed prophylactically.

Question 51

Early dumping

Answer 51

Early dumping ensues 15 to 30 minutes after eating and is thought to be due to the rapid entry of hyperosmotic foods into the jejunum.

It is due to rapid fluid shifts into the intestinal lumen with a meal which results in a parasympathetic response leading to a reduction in systemic vascular resistance, an effect called “splanchnic blood pooling.”

Symptoms include cramping abdominal pain, voluminous diarrhea, bloating, dizziness, nausea, flushing, and tachycardia; symptoms result from hypovolemia and a subsequent sympathetic response.

Question 52

is triggered by consumption of simple sugars, acidic foods, and nutrient-rich drinks such as Gatorade

Answer 52

Dumping syndrome

Early dumping is usually self-limited and resolves between 7 and 12 weeks after surgery.

Late dumping syndrome occurs 2 to 3 hours after a meal and is secondary to rapid glucose absorption, subsequent hyperglycemia, and release of glucagon-like peptide-1 and gastric inhibitory polypeptide.

Question 53

Nutritional Deficiencies

Answer 53

patients who do not take daily vitamins postoperatively or patients who experience frequent vomiting are at increased risk of developing such deficiencies, most common of which are protein, iron, vitamin B12, folate, calcium, and the fat-soluble vitamins A, D, E, and K.

Question 54

Nutritional Deficiencies

Answer 54

The parietal cells of the stomach produce intrinsic factor (IF), which is necessary for vitamin B12 absorption in the terminal ileum

Calcium, iron, and folate deficiency can occur because they
are absorbed mainly in the duodenum and proximal jejunum.

Question 55

Patients who undergo RYGB

Answer 55

Patients who undergo RYGB may develop B12 deficiency because RYGB separates the parietal cells in the fundus of the stomach from the smaller gastric pouch.

Question 56

Ulceration

Answer 56

Ulceration at the gastrojejunal anastomosis (GJA) is a common late complication of RYGB.

GJA ulceration often develops in the first 3 months postoperatively but can occur at any time.

Anastomotic ulcers may be due to small amounts of acid produced by the gastric pouch, ischemia, bile acid reflux, Hp infection, NSAIDs, smoking, alcohol, foreign bodies such as non- absorbable sutures or staples, or tension on the Roux lim

Question 57

Treatment of Ulceration

Answer 57

In patients with
RYGB, anastomotic ulcers should be treated with soluble PPI
or capsules that are broken open, taken twice daily, and tapered
over 6 months.

Sucralfate solution at 1 g 4 times daily should
be used concurrently when possible; the tablet form of PPI does
not appear to be as effective. Bile reflux can be treated with bile
acid binders such as cholestyramine or colestipol. Smoking cessation is critical.

Question 58

stenosis

Answer 58

stomal stenosis is present if the standard 9.5 mm endoscope cannot traverse the anastomosis.

Treatment of stomal stenosis can be performed with a through- the-scope (TTS) balloon, Savary dilator, or electrosurgical incision. Balloon dilation is the most commonly used technique and is successful in more than 90% of cases.

The balloon catheter should be advanced beyond the GJA, with care to avoid entry into the blind limb; a guidewire and/or fluoroscopic imaging can be used when observation of catheter advancement is sub-optimal, or resistance is encountered.