Quest 1 Flashcards
What are the advantages of classifying obesity as a disease?
changes the narrative about it (not a choice
forces medical community to respond
call to action to find solutions, causes, etc
WHat are the disadvantages to calling obesity a disease?
may promote despair
panic when moderate weight increase
promote stigma
external locus of control
WHat is the definition of obesity
chronic/progressive condition, characterized by excess body fat
commonly classified using BMI over 30, but not ideal as it doesnt take body comp into account
WHat is the edmonton staging system?
ranks severity of obesity based on clinical assessment of weight related health problems, mental health, and quality of life
uses a holistic view, used to assess if pt is candidate for bariatric surgery
What are the 5 stages of the edmonton staging system?
stage 0 - normal
stage 1 - subclinical risk factors with mild symptoms
stage 2 - begins meeting clinical criteria for admission, established obesity related co-morbidities
stage 3 - significant obesity related organ damage/limitations
stage 4 - severe damage and symptoms
What are the 3 strategic goals of obesity canada?
- address the social stigma associated with obesity
-change the way policy makers and health professionals approach obesity
-Improving access to evidence-based prevention and treatment resources
What is weight bias
negative stereotyping of individuals with obesity
what is implicit vs explicit bias
implicit is bias that you arent consciously aware of
explicit is bias that you are aware you have
What kind of stigmas do health care providers have around weight?
bad patients
bad people
ill-equipped to treat them
What are some individual health consequences of weight stigma?
causes unhealthy eating/less activity
psychological disorders
stress-induced pathophysiology
substandard health care and lower health care utilization
what are some key messages about weight bias from the everyBODY matters summit
weight bias and obesity discrimination will not be tolerated in education, health care, and public policy
obesity should not be recognized and treated as a chronic disease in healthcare
weight and health need to be decoupled in education
what are some key strategies to reduce weight bias from the everyBODY matters summit
create resources to support policy makers
use personal narratives from people living with obesity to engage the audiences and communicate anti-discrimination messages
develop a better clinical definition for obesity
What are some strategies to address weight stigma in primary care providers
increase provider empathy
altered perceived norms around stigma
have providers examine their own biases
educate providers on complexity of obesity
reduce focus on weight
pt centered communication
welcoming environment that values diversity
WHat is people first language
saying people with obesity instead of saying obese people
What is reductionist thinking
thinking that complex systems can be explained by reducing em to a small number of variables
looking at components of a system instead of the system as a whole
applies a one size fits all approach
What is systems science
focuses on the connections between components rather than the components themselves
ie: a system is more than the sum of its parts
Why is a systems approach important
Allows you to focus on a higher level and understand the interactions and driving forces that cause the result
What are the benefits of using a reduced foresight map
shows the connections, but identifys the strongest connections with bolder lines
What are some solutions to complex problems
consider that individuals matter
match capacity to complexity
set functional goals and directions, distributing decision, action, and authority
understand the system and look for modifiable connections that can shift feedback loops to balance instead
What is energy balance
relation between energy intake and expenditure
energy cant be destroyed, just transfered
What happens with an energy surplus
weight gain and increase in fat mass
How is adipose tissue remodeled
differentiation of precursors into adipocytes (hyperplasia) and the increase of cell size of the adipocytes (hypertrophy)
hyperplasia is healthier as it can maintain proper vascularity, but hypertrophic tissue is associated with increased hypoxia and inflammation due to expansion
combination of what increases body weight
increase in adipose tissue mass (size or number)
increase in lean body mass (muscle hypertrophy)
increase in glycogen mass (max 1-2kg change)
increase in water mass
What are the 4 dietary macronutrients
carbs (fuel, 4kcal/g)
protein (growth/repair, 4kcal/g)
lipids (fuel/excess stored as lipid with adipose tissue, 9kcal/g)
alcohol (fuel, dysregulates lipid metabolism, 7kcal/g)
Which macronutrient is the best for weight loss
protein, the rest dont really matter, total calorie count is the most important
What is the microbiome and microbiota
microbiome: genetic material of all non-human microbes
microbiota: the microbes themselves
How are microbiota and obesity linked
increased energy harvesting from carbs that otherwise would be indigestible - more calories extracted from food
increased inflammation
What are the components of total energy expenditure
basal metabolic rate (60-75% of TEE)
Thermic effect of food (10-15% of TEE)
activity thermogenesis (NEAT=20%, EAT = 10%)
What is basal metabolic rate
energy expended for homeostatic processes
mean rate of bmr is 0.863kcal/kg/hr
higher for men, lowers with age, and is less in overweight people.
obese people have lowest rate
positively correlated with muscle mass
genetically influenced
What is NEAT
non exercise movements, very variable, low levels of neat associated with obesity
Does TEE increase linearly with physical activity
no, in the constrained model of energy expenditure, the body adapts to increased physical activity by reducing energy spent on other physiological activity, maintaining the TEE within a narrow range of baseline
more not always better beyond a threshold
What is the thermic effect of food
diet-induced thermogenesis
an increase in metabolism after food intake, energy needed to process and store the food, depends on the content of the food
decreases with age, and higher levels of activity are associated with higher TEF
TEF of protein>carbs>lipids
fiber rich diets and whole foods provide higher TEF
eating one large meal has higher TEF than multiple smaller meals
What is a fat depot
accumulation of fat in specific area of the body
compare subcutaneous adipose tissue and visceral adipose tissue
both have protective and pathogenic characteristics, but SAT is more benign
increase in visceral adiposity is a marker for dysfunction of SAT and global fat dysfunction, accounting for association with metabolic diseases
VAT has higher sensitivity to catecholamines, lower sensitivity to insulin, and direct portal access to liver
What is White adipose tissue
95% of adipose tissue
functions are for energy/vitamin storage
insulation
protection
endocrine organ
unilocular, thin rim of cytoplasm, thickened perinuclear cytoplasm with small lipid droplets
flattened nucleus on periphery with visual nucleolus
composed of adipocytes, fibroblasts, smooth muscle cells, endothelial cells, and blood cells
What is brown adipose tissue
main function is for thermogenesis
darker appearance due to higher population of mitochondria
multiocular (many lipid droplets)
in highly vasculated and innervated areas
develops from muscular progenitors
mitochondria has clear, ordered crista
UNIQUELY OVEREXPRESSES UNCOUPLING PROTEIN 1
UCP1 uncouples protein gradient from ATP synthase during oxidative phosphorylation, releasing heat
BAT is inversely correlated with BMI
How do did brown and white adipocytes develop?
brown - developed from shared precursor of skeletal muscle that expresses Myf5 positive precursors
white - developed from shared precursor of skeletal muscle that expresses Myf5 negative precursors (some BAT also develops from these, creating beige adipose tissue)
What are beige adipocytes
bright inducible/recruitable brown (rBAT)
inducible thermogenic cells from WAT
develop due to exposure to cold, cancer, bariatric surgery, adrenergic stress, etc
Beige fat is multilocular and thermogenic like brown fat, but has a lower expression of UCP1 compared to BAT
How are beige adipocytes formed?
Transdifferentiating of mature WAs to BAs
induction of differentiation of BA progenitors
What are adipokines
peptides secreted from adipose tissue that communicate with the brain, liver, etc
similar to hormones
become dysregulated when adipocytes reach critical level of adiposity
What is adipokine secretion associated with in obesity
pro inflammatory morbidity increasing pattern
non obesity adipokines are overall more protective
What is leptin?
Adipokine that promotes satiety
obese mice are unable to produce enough leptin (obesity gene is expressed in WAT), while diabetic mice produce it but cannot respond to it due to defective satiety center
expression is proportional to WAT mass
acts on LEPRb-expressing neurons on hypothalamus
How does leptin affect energy balance?
binding to hypothalamus inhibits orexigenic NPY/AgRP (appetite stimulators) and stimulates anorexigenic POMC/CART (appetite suppressors)
How does leptin affect the immune system
upregulates phagocytosis and mediates proinflammatory cytokines such as TNF-alpha and IL-6
activates T-cell/B-cell proliferation
What is adiponectin
adipocyte complement related protein released from WAT
antihyperglycemic, antiatherogenic, and anti-inflammatory
inverse relationship between adiponectin and obesity
What does adiponectin do
increases insulin sensitivity in muscle, promotes insulin secretion in pancreas, activates glucose transport and decreases inflammation in liver, and increases insulin stimulated glucose uptake in adipose tissue
What is PAI-1
Plasminogen activator inhibitor
inhibits plasminogen activators
elevated levels promote thrombosis and atherosclerosis
inhibits blood clot breakdown
What is IL6
Interleukin 6
regulator of immune system
increased production during obesity
mediators of inflammation in obesity
What is TNF alpha
proiflammatory cytokine that increases in obesity
What is the inflammation response
macrophages and mast cells release leukocytes
neutrophils are activated
macrophages phagocytose the activated leukocytes
if injury persists, different inflammation response agents are recruited, like t cells
How is the inflammation response altered with obesity?
immune response normally for host defence remains triggered, causing low grade chronic inflammation
increased M1 concentration causes damage in obesity (M2 in lean)
What are 4 potential mechanisms towards infammation
adipocyte hypertrophy leading to rupture
oxidative stress of overfeeding (esp pro-inflammatory foods)
microbiota promoted inflammation
increases in reactive oxygen species
How are diabetes and obesity related
obesity is the best predictor of type 2 diabetes
risk rises with increased teenage weight gain
insulin resistance is part of early progression towards type 2
obesity strongly associated with insulin resistance, due to dysregulation of adipokines and more free fatty acids released into the blood in obesity compromising insulin receptor expression/function
how is atherosclerosis promoted in obesity?
associated with higher C-reactive protein - a key inflammatory marker for CVD
pro-inflammatory adipokines increase adhesion molecules on endothelial surface
elevated insulin has proliferative effects on smooth muscle cells
WHat is the obesity paradox
it increases the risk of heart failure, however it can also exert protective effects in patients with a confirmed heart failure diagnosis
half have reduced ejection fraction, while the other half have increased ejection fraction
possible due to preserved muscle mass, lower SVR, or increased lean mass
How does obesity influence cancer
tumots invade areas rich in adipose tissue (WAT)
increase pro inflammatory adipokines
makes tumors more aggressive
WHat is the relation between obesity and polycystic ovarian syndrome
more androgen production, causes menstrual irregularities
40-80% of women with this are obese
