Obesity Flashcards
What is the following BMI cut-off points for:
- underweight
- normal weight
- overweight
- obese
- morbidly obese
- underweight <18.5
- normal weight 18.5-24.9
- overweight 25-29.9
- obese >30
- morbidly obese >40
What is the association between insulin and obesity?
insulin:
- decreases the rate of lipolysis in adipose tissue (and lowers plasma fatty acid level)
- -> increases the uptake of triglycerides from blood into adipose tissue
- stimulates fatty acids and triglyceride synthesis in tissues
- decreases rate of fatty acid oxidation in muscle and liver
Which T2D drugs have the following impact on insulin levels:
- increase
- stable
- decrease
- increase: insulin injections, sulfonylureas, TZD
- stable: metformin, DPP-4 inhibitors
- decrease: SGLT2 inhibitors
Describe the thrift gene hypothesis.
Genes that predispose people to obesity could have a selective advantage to populations that experience frequent starvation
What are the characteristics of syndromic monogenic obesity? Give examples of syndromic monogenic obesity.
Characteristics:
- mental retardation
- dysmorphic features
- organ specific abnormalities
Examples:
- Prader-Willi syndrome
- Bardet-Biedl + Alström Syndrome
- primary cilium has a key role in differentiation of adipocytes
- the cilia mediate leptin receptor signalling
What pathway is involved in non-syndromic monogenic obesity?
Leptin-melanocortin pathway
What is polygenic obesity?
227 genetic variants involved in different biologic pathways have been identified
- involves CNS, food sensing + digestion, insulin signalling, lipid metabolism, muscle and liver biology, gut microbiotica
- also involved in adipocyte differentiation (ciliopathies and mutations in PPAR gamma 2 )
What conditions/disease does obesity increase the risk of?
- cardiovascular disease
- pulmonary disease
- metabolic disease
- osteoarticular disease
- cancer
- psychiatric illnesses
How can obesity cause T2D/what is the association between the two?
Obesity causes:
- chronic inflammation of the fat tissue
- altered adipokine levels
- -> especially leptin = this causes tissues to become leptin resistant
- breakdown of fat metabolism
- -> accumulation of lipids in tissue
- breakdown of glucose metabolism
What are the main treatment options for obesity (non pharmacological/pharmacological)?
- PREVENTION/LIFESTYLE CHANGES!!
- Orlistat: gastric and pancreatic lipase inhibitor (reduced absorption of dietary fat)
- Phentermine: noradrenaline transporter inhibitor - appetite suppression
- Liraglutide: GLP1 agonist - reduced appetite
- Lorcaserin: Selective 5-HT agonist - increased satiety
When is surgery indicated in obesity?
When BMI >40 or >35 with obesity-related complications
- must go through weight management course first
What is the difference between restrictive and malabsorption procedures in the treatment of obesity?
- restrictive: restrict ability to eat
- e.g. = adjustable gastric band - malabsorptive: reduce ability to absorb nutrients
- e.g. = gastric bypass
