Obesity

Question 1

Obesity Definitions

Answer 1

BMI:

• Overweight = 25-29.9
• Obese = 30 +

Central Obesity:

• Waist circumference - >102cm M and >88cm F
• Waist to hip ratio - >.90M and >.85F

Up to 70% of variation in weight is genetic
Weight is homostatically regulated

Question 2

Role of obesity in cancer

Answer 2

ENDOMETRIAL
Oesophagus
Renal
Gallbladder
Colon
Breast

Question 3

Other diseases associated with obesity

Answer 3

GORD
Gallbladder disease
OSA
CVD
HTN
DM
Dyslipidaemia
OA
Gout

Question 4

Pathophysiology of adipose tissue

Answer 4

Increases hormones, cytokines and free fatty acids

–> insulin resistance

–> endothelial dysfunction

Question 5

Mechanisms of energy expenditure

Answer 5

Involuntary = BMR
NEAT
Obligatory
Voluntary

Question 6

Mutations causing human obesity

Answer 6

Ob - leptin deficient

ObR - defective leptin signalling

MC4-R - impaired function of MC4-R –> obese and increase muscle mass

Question 7

Role of leptin

Answer 7

Synthesized by adipocytes - increased with increased size of cells

Reduces the expression of neurotransmitters that increase food intake

Inhibits food intake and increases energy expenditure

Most obese people are leptin resistant

Question 8

Satiety and hunger signals

Answer 8

Hunger = Ghrelin

Satiety = CCK, PP, GLP-1, Oxyntomodulin, PYY, Însulin, Leptin

Question 9

Obesity management

Answer 9

Diet and lifestyle changes

Medications:

• Phentermine - sympathomimetic amine
• Topiramate - Monosaccharide antiepileptic
• Orlistat - intestinal lipase inhibitor
• Liraglutide - GLP-1 receptor agonist

Bariatric surgery - gastric bypass > gastric band

Question 10

Effect of gastric band on weight loss?

Answer 10

RESTRICTS INTAKE
Reduces food intake
Gastric emptying is unchanged
Reduces leptin
Improves glucose control - reduces fasting BGLs and insulin sensitivity
Increases ghrelin
Unchanged GLP-1

Question 11

Effect of gastric sleeve on weight loss?

Answer 11

RESTRICT INTAKE
Reduces food intake
Increases gastric emptying times
Reduces leptin
Improves glucose control - reduces fasting BGLs and insulin sensitivity
Reduced ghrelin
Increased GLP-1

Question 12

Effect of roux-en-Y on weight loss?

Answer 12

RESTRICTS INTAKE AND MALABSORPTION
Reduces food intake
Unclear effect on gastric emptying
Reduces leptin
Improved glucose control
Reduced ghrelin
Increased GLP-1