Obesity Flashcards
What is weight stigma?
Discrimination or stereotyping based on one’s weight.
What are the emotional effects of weight stigma?
Depression, anxiety, low self-esteem, social rejection, suicide
What are the physical effects of weight stigma?
Unhealthy weight control behaviours, binge eating, avoidance of physical activity
What are the quality of healthcare effects of weight stigma?
More likely to delay or cancel appointments or preventative health services
How many men and women are affected by obesity?
1/4 men and women
Is severe obesity prevalence higher for men or women?
Women
When did the obesity epidemic become apparent?
Clear increase around 1977, coincides with changes in food environment
What changes in food environment occurred?
- Eating poor food is easier
- Poorest families need to spend 74% of expendable income to meet dietary guidelines
- We are far less active
What are the obesity levels like in 2020?
Highest ever levels worldwide
What is very high waist circumference taken to be in men/women?
Men - 102cm
Women - 88cm
What are the tiers of obesity services?
Tier 1-4
With each tier providing different intervention.
What is tier 1?
Primary activity, population level public health prevention, identifying those at risk, referring into appropriate interventions
What is tier 2?
Community based weight management services
What is tier 3?
Specialist weight management services for people with severe and complex obesity
What is tier 4?
Bariatric (weight loss) surgery
How can consultations be improved regarding obesity?
- Setting the agenda
- Making decisions and setting targets
- Exchanging information
- Quick assessment of motivation and confidence to change
What are the most positive and motivating obesity campaign messages?
- Focus on changing behaviours and improving health
- Recognise the many determinants of overweight and obesity rather than focusing on individual responsibility
How can weight stigma be avoided?
- Respect diversity and avoid stereotypes
- Use positive and appropriate language, factual terminology and open-ended questions. This can help you build a good rapport with your patient. Avoid using accusatory language so the patient does not feel like you are blaming them for their condition.
How can you be non-judgementally curious?
- Acknowledge that weight management can be difficult
- Do not make assumptions about a person’s life, lifestyle or motivation
- Open-ended questions
What loss of initial weight is realistic?
5-10% loss of initial weight is realistic, achievable and results in improvements (powers blood pressure, improves diabetic control and reduces cholesterol(
What is realistic weight loss?
0.5-1kg loss per week (loss in fat while preserving lean body mass)
What are the top 5 celeb diets to avoid in 2019?
- Blood type diets
- Drinking your own pee
- Detox teas / skinny coffees
- Slimming sachets
- Alkaline water
When should pharmacotherapy be considered?
Only after dietary, exercise and behavioural approaches have been started and evaluated
When should orlistat be prescribed?
Only as part of an overall plan for managing obesity in adults who meet one of the following criteria: a BMI of 28.0 kg/m2 or more with associated risk factors or a BMI of 30.0 kg/m2 or more. (Affects fat absorption)
When is bariatric surgery considered?
- BMI of 40 or more (or BMI between 35-40 and other significant diseases)
- Person has been receiving or will receive intensive management in a tier 3 service
- The person is generally fit for anaesthesia and surgery.
- The person commits to the need for long-term follow-up.
What are the types of bariatric surgery?
Gastric band Gastric bypass Sleeve gastrectomy (remove bit of gut, affects appetite hormones)
How important is weight maintenance?
Is of equal importance to the weight loss phase
Where are the ‘hunger’ and ‘satiety’ centres?
In the hypothalamus
What is ghrelin?
‘Hunger hormone’ because it stimulates appetite, increases food intake and promotes fat storage
When is ghrelin released?
Released when the stomach is empty
Where is ghrelin released from?
Mainly by the stomach with small amounts also released by the small intestine, pancreas and brain
Where does ghrelin travel?
To the hypothalamus –> is a powerful hypothalamic orexigenic (appetite-inducing) agent
What does orexigenic mean?
Appetite-inducing
How does ghrelin present when released in the brain?
Neuropeptide
What are anorexigens?
Hunger suppressors
What gut/pancreatic peptides are anorexigens?
CCK Insulin GLP-1 Peptide YY Oxyntomodulin Somatostatin
As do foodstuffs, such as glucose, amino acids, and lipids, at least some via direct actions on the hypothalamus
Is the hypothalamus protected by the blood brain barrier?
No
What is leptin?
Hormone released by adipocytes (signals to the hypothalamus)
What is function of leptin?
Leptin does not affect food intake from meal to meal but, instead, acts to alter food intake and control energy expenditure over the long term
Central effects and potentiate insulin
How do leptin and insulin interact?
Leptin and insulin directly regulate each other : 0 leptin inhibits insulin; insulin stimulates leptin synthesis and secretion.
How does weight loss affect leptin?
Levels of leptin fall –> decreases insulin –> hunger increases
What is effect of leptin on hunger?
Higher leptin levels decreases appetite and food intake
What is adiponectin? Where is it released from?
A protein hormone released from adipose tissue
What is effect of high levels of adiponectin?
Decreases insulin resistance as sensitises liver and muscle to insulin
Can accompany weight loss
What is effect of low levels of adiponectin?
Increases insulin resistance
Can accompany obesity
What cytokines released by adipocytes affect weight?
Pro-inflammatory cytokines –> TNF-a and IL-6
Inhibit insulin and leptin
What is the solitary tract?
The solitary tract is a compact fibre bundle that extends longitudinally through the posterolateral region of the medulla (brainstem)
Descends to the upper cervical segments of the spinal cord
What is the solitary tract surrounded by?
Nucleus of the solitary tract
What does the nucleus of the solitary tract do?
Collect central and peripheral messages, including from anorexigens
These then send messages to arcuate nucleus
Where do projections from the arcuate nucleus go to?
- Satiety centre in the ventromedial nucleus
- Hunger centre in lateral hypothalamic area
Within arcuate nucleus, there are bunches of neurones with different characteristics.
What does the arcuate nucleus contain?
- Anorexigenic neurones
- Orexigenic neurones
What do anorexigenic neurones make?
What does this lead to?
Secrete proopiomelanocortin (POMC) and “cocaine-amphetamine-related transcript” (CART)
Leads to suppression of appetite
What do orexigenic neurones make?
What does this lead to?
Orexigenic neurons secrete Agouti-related peptide (AGRP) and neuropeptide Y (NPY)
Stimulates appetite
What does AGRP inhibit?
Melanocortin receptors
Where is the satiety centre?
In the ventromedial nucleus
Where is the hunger centre?
In the lateral hypothalamic area
What are ketone bodies made from?
Fatty acids –> acetyl CoA –> ketone bodies
What is breath like of someone starving?
Can smell acetone due to ketone bodies being produced
Effects of extreme starvation?
- Wasting of muscle
- Muscle fatigue and reduced exercise capacity
- Diminished respiratory capacity
- Slowed heart rate, and decreased contractility
- Loss of heat-generating capacity
- Apathy
- Death from respiratory or cardiac failure, or infection
What is anorexia nervosa?
Body weight more than 15% below standard (BMI < 17.5)
Weight loss due to voluntary abstinence
What is bulimia nervosa?
Similar but without the low body weight
What typical biochemical abnormalities are associated with bulimia?
- Metabolic alkalosis due to volume contraction
- Hypokalaemia
What is alkalosis due to volume contraction?
Increase in blood pH that occurs as a result of fluid losses (volume contraction).
The change in pH is especially pronounced with acidic fluid losses caused by problems like vomiting.
What is BMI?
(weight in kg) / (height in metres) squared
What is the normal BMI range?
18.5-24.99
What BMI range is overweight?
25-29.99
What BMI range is obese?
> 30
What BMI range is underweight?
<18.5
In obese people, what are the levels of leptin and grehlin like?
Leptin is high and grehlin is low
What are dangers of obesity on musculoskeletal system?
Osteoarthritis (degeneration of joint cartilage & bone); lower back pain.
Due to sheer weight you are carrying
What are dangers of obesity on circulatory system?
Hypertension (→ coronary heart disease, stroke & renal failure); deep vein thrombosis; pulmonary embolism
Heart has to work harder to supply more fat
What are dangers of obesity on metabolic and endocrine systems?
Type 2 diabetes is substantially raised (65-75%); Dyslipidaemia; Metabolic syndrome (high blood glucose, blood pressure, cholesterol)
What are dangers of obesity on cancers?
Endometrial, breast and colon cancers.
Higher risk (also due to low grade inflammatory response)
What are dangers of obesity on reproductive and urological systems?
- Stress incontinence, menstrual abnormalities, polycystic ovarian syndrome; infertility.
- Erectile dysfunction.
- Offspring
What are dangers of obesity on respiratory system?
Sleep apnoea
What are dangers of obesity on gastrointestinal and liver?
Non-alcoholic fatty liver disease; gastro-oesophageal reflux; gall stones.
What are dangers of obesity on psychological and social problems?
Stress; low self-esteem; social disadvantage; depression; reduced libido.
What is the ‘metabolic syndrome?
Must have at least 3 out of:
- Obesity (waist circumference)
- Type II diabetes mellitus
- Hypertension
- High plasma triglycerides (hyperlipidaemia)
- Low HDL cholesterol
How does obesity affect insulin? What can this then lead to?
Obesity leads to insulin resistance, and both lead to production of pro-inflammatory cytokines, which seem to underlie the cardiovascular disease.
What is effect of NEFA (non-esterified fatty acids) on liver?
Makes liver less sensitive to insulin and alters lipid handling.
Also, impairs B cell insulin release
What does higher insulin resistance lead to?
Higher plasma insulin and higher plasma glucose
Difference in developing and excess obesity?
Developing obesity tends to suppress appetite and increase BMR, until a balance is reached.
Excess obesity induces insulin resistance and chronic inflammatory changes.
What is the metabolic syndrome associated with?
CVS disease
