Obesity Flashcards
Obesity Definitions
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
Role of obesity in cancer
ENDOMETRIAL Oesophagus Renal Gallbladder Colon Breast
Other diseases associated with obesity
GORD Gallbladder disease OSA CVD HTN DM Dyslipidaemia OA Gout
Pathophysiology of adipose tissue
Increases hormones, cytokines and free fatty acids
–> insulin resistance
–> endothelial dysfunction
Mechanisms of energy expenditure
Involuntary = BMR
NEAT
Obligatory
Voluntary
Mutations causing human obesity
Ob - leptin deficient
ObR - defective leptin signalling
MC4-R - impaired function of MC4-R –> obese and increase muscle mass
Role of leptin
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
Satiety and hunger signals
Hunger = Ghrelin
Satiety = CCK, PP, GLP-1, Oxyntomodulin, PYY, Însulin, Leptin
Obesity management
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
Effect of gastric band on weight loss?
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
Effect of gastric sleeve on weight loss?
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
Effect of roux-en-Y on weight loss?
RESTRICTS INTAKE AND MALABSORPTION Reduces food intake Unclear effect on gastric emptying Reduces leptin Improved glucose control Reduced ghrelin Increased GLP-1
