Lecture 15 - Obesity

Question 1

Define obesity

Answer 1

Imbalance between calories consumed and energy expanded with metabolic parameters and appetite regulation via gastric and peripheral nervous systems

Question 2

Define a underweight BMI

Answer 2

<18.5

Question 3

Define a healthy weight BMI

Answer 3

18.5-24.9

Question 4

Define a overweight BMI

Question 5

Define baritatrics

Answer 5

Interventions used to manage patients with obesity
could be medical management - e..g surgical interventions

Question 6

Define obesity I BMI

Answer 6

30-34.9
Certain interventions available on the NHS

Question 7

What is the limitation of BMI?

Answer 7

Does not take into account patients muscle mass

Question 8

Define obesity II BMI

Answer 8

35-39.9

Question 9

Define obesity III BMI

Answer 9

40 or more

Question 10

Name one of the main causes of obesity

Answer 10

Overeating

Question 11

Define ghrelin hormone

Answer 11

primarily produced in the gastric fundus and is responsible for appetite stimulation
makes you feel hungry so encourages you to eat - less likely to be suppressed with patients who are obese
obesity - associated with reduced post-prandial ghrelin suppression

Question 12

Define anorexigenic intestinal hormone

Answer 12

Includes GLP-1, peptide YY (PYY) and cholecystokinin (CCK)
Secreted in response to food intake, involved in digestion, insulin secretion and post-digestive metabolism and satiety
Obese patients - delayed, reduced or otherwise attenuated activity of anorexigenic hormone
(Body not telling you to stop eating)

Question 13

Define leptin hormone

Answer 13

Predominately secreted by white adipose tissue
circulating levels correlate with fat mass and represent a hormonal signal of body energy stores
in individuals with more body fat, serum, plasma and CSF leptin levels are elevated
Sensitivity to leptin is reduced in people with obesity, reducing satiety despite high energy stores

Question 14

Define liraglutide

Answer 14

Management of obesity
GLP-1 agonist
BMI of at least 35 and they have non-diabetic hyperglycaemia and a high risk of CVD based on risk factors such as HTN and dyslipidaemia
Prescribed in secondary care by a specialist multidisciplinary tier 3 weight management service
Has benefits on every meal on the day

Question 15

Define the role of GLP-1

Answer 15

Gut hormone released into the circulation after meal ingestion which stimulates and inhibits glucagon release
Can suppress food intake and appetite and decelerate gastric emptying and induce satiety therefore reducing appetite and food intake
Attached acyl chain allows non-covalent bonding to albumin

Question 16

Define semaglutide

Answer 16

BMI of at least 35 or meet criteria for referral to a specialist weight management service
Used for a maximum of 2 years and within a specialist weight management service

Question 17

Define the criteria for obesity surgery

Answer 17

Have a BI of 40 or more or between 35-40 and other significant disease that could be improved if they lost weight
all appropriate non-surgical measures have been tired but the person has not achieved or maintained adequate, clinically beneficial weight loss
The person has been receiving or will receive intensive management in a tier 3 service
Person is generally fit for anaesthesia and surgery
Person commits to the need for long-term follow-up

Question 18

Define gastric restriction - intra gastric balloon

Answer 18

A balloon inserted to restrict the volume of the stomach
The stomach is still there and intact
Volume of stomach is reduced
Feel more full from a small volume of food
Is reversible can just be removed

Question 19

Define gastric restriction - adjustable gastric banding

Answer 19

Stomach is still present
Have a physical band that presses on the stomach to make it harder for food to pass through
When the top pouch of the stomach is filled you will start to feel full so you will naturally eat less
Reversible if there is complications

Question 20

Define bariatric surgery

Answer 20

Proportion of the stomach is physically removed

Question 21

Define sleeve gastrectomy

Answer 21

Stomach is significantly shrunk and part of it is removed
Stomach volume and SA is reduced
All of duodenum still present - still expect all of the absorption from the small intestine

Question 22

Define gastic bypass surgery

Answer 22

Proportion of the stomach is reduced significantly and its connected a little bit further down to the duodenum
Losing absorption of medications due to the loss of duodenum

Question 23

Define the complications of surgery (operative)

Answer 23

Thromboembolism
Bleeding
Pneumonia - lying flat and not being mobile
Stenosis - narrowing and can lead to blockages
Ulcers
Infection around wound site
Hernia - portion of intestine protrudes out through the abdominal wall
Peritonitis - infection in the lining of the outer stomach and the abdomen
Death (1-2%)

Question 24

Define the long-term complications (20-30%)

Answer 24

Iron deficiency
Calcium and vitamin D deficiency
Vit B-112 deficiency
Vit B-1 (thiamine) deficiency
Protein deficiency
Gallstones
Weight regain

Question 25

Describe the pH changes

Answer 25

Partitioning of the stomach results in decreased production of HCL - drugs dependent on acidity will have reduced absorption as a result
Drugs in a more neutral pH will have increased absorption likely still acidic but closer to neutral
may affect BA of drugs/formulations whose absorption is pH dependent
may be possible to use alternative salt forms or to artificially alter gastric pH

Question 26

How does GI tract motility affect absorption?

Answer 26

If movement through the GI tract is too fast - drug will pass through the system without being absorbed
If movement through the GI tract is too slow, the onset of pharmacological effect will be delayed the drug may be degraded or the epithelium may be irritated

Question 27

How does a reduction in gastric volume affect absorption?

Answer 27

Reduced SA of stomach - reduced volume from 1000-1500ml to 30ml
Limited no of drugs are absorbed through the stomach wall
Drugs in aqueous solution more rapidly absorbed than those in oily solutions, suspensions or solid forms
Particular caution with drugs with narrow therapeutic index and sustained/ MR preparations
Post-op oedema may also reduce stomach volume and opening into stomach
Solid oral medications might get stuck
Avoid effervescent formulations
Increased potential of damage to gastric mucosa e.g. bisphosphates and NSAIDs

Question 28

What are the changes to VofD?

Answer 28

Patients may rapidly lose weight post-op - altering the VofD
Increased circulating volume of drugs that are highly lipid-soluble
Close monitoring essential
Dose adjustment may be needed (e..g beta blockers)

Question 29

What are the pre-op considerations for bariatric surgery?

Answer 29

Complex polypharmacy due to co-morbidities
Advise an appropriate peri-operative medicines management
VTE prophylaxis
Initiate formulation/ drug changes proactively

Question 30

What are the post-op considerations for bariatric surgery?

Answer 30

Close monitoring for efficacy of orally administrated drug therapy
If lack of efficacy then suspect poor absorption
Consider change of formulation or route
Review drugs with GI Side effects e.g. NSAIDS
Consider PPI prophylaxis
VIt B-12 deficiency common due to reduction of functioning parietal cells and HCL in stomach
3-monthly B12 injections effective
Bypass patients prone to deficiencies in fat-soluble vitamins, calcium and iron supplementation
Deficiencies less common in banding patients