Flashcards in Week 111 - Obesity Deck (63):
What is the normal value for HbA1c and what does it represent?
What HbA1c value is the target for treatment?
What is Metformin and how is it useful in treating obesity?
It is an antidiabetic drug but puts patients off their food.
What is Orlistat and how does it work?
It is a lipase inhibitor so helps to reduce the absorption of fats.
What are the side effects of orlistat?
Steatorrhea, fecal incontinence.
When a patient has obesity, Diabetes Mellitus type II, Hypertension and Microalbuminuria, what condition are they said to have?
What four conditions are required for a diagnosis of metabolic syndrome?
Obesity, Diabetes Mellitus type II, Hypertension and Microalbuminuria.
In how many cases of obesity is there a family history?
What are some of the very rare secondary causes of obesity?
Hypothyroidism, Glucocorticoid excess, Hypothalamic dysfunction, Growth hormone deficiency and Pader Willi syndrome.
What are some of the medical complications caused by Obesity?
Pulmonary disease, Idiopathic intracranial hypertension, Stroke, Cataracts, CHD, Nonalcoholic fatty liver disease, Gall bladder disease, Gynaecological abnormalities, Osteoarthritis, Skin, Gout, Phlebitis, Cancer, Severe pancreatitis.
Which two drugs used for treatment of obesity have now been removed?
Sibutramine and Rimonabant.
What is GLP-1? And how may it be used in future management of obesity?
GLP-1 is naturally secreted by the small intestine when food is ingested, it increases the activity of Beta-cells resulting in increased insulin. It also decreases the activity of Alpha-cells resulting in a decreased amount of glucagon. This creates a feeling of satiety.
What are the nice guidelines for bariatric surgery?
• BMI >40 or >35 with comorbidities.
• Minimum 5 years of obesity.
• Failure of conservative treatment.
• No alcoholism / major psychiatric illness.
• No pregnancy within 2 years
What are the additional requirements to the nice guidelines for bariatric surgery in wales?
• BMI >50
• Uncontrolled type II DM
• Obstructive sleep apnoea.
What are the three broad types of bariatric surgery?
Restrictive, Malabsorptive and Combined.
Restictive is one of the three types of bariatric surgery (along with Malabsorptive and Combined) What are the two types of operation?
• Laproscopic gastric banding.
• Laproscopic sleeve gastrectomy.
Malabsorptive is one of three types of bariatric surgery (along with restrictive and combined), What is the name of the surgery performed?
Laproscopic biliary-pancreatic diversion and duodenal switch.
Combined is one of three types of bariatric surgery (along with malabsorptive and restrictive), What is the name of the surgery performed?
Laproscopic Gastric Bypass
Which form of bariatric surgery is the gold standard and what type is it?
Laproscopic sleeve gastrectomy - Restrictive
How is Laproscopic Gastric Banding performed and what type of bariatric surgery is it?
A band is fitted around the upper part of the stomach to create a small pouch with a narrow stoma. The band is connected to a port through which fluid can be passed to increase or decrease the size of the band. This makes the patient feel full sooner.
What are the complications of Laproscopic Gastric Banding?
The band can slip out of place, reflux, erosion of the band, infection of the port, 10-15% will require further surgery. DOES NOT WORK FOR CHOCOLATE!
What is Laproscopic sleeve gastrectomy?
Restrictive bariatric surgery. The stomach is changed into a tube by stapling the stomach this reduces portion size and transit time, so is also malabsorptive.
What are the complications of Laproscopic sleeve gastrectomy?
Reflux, stenosis and dilation.
What is bilio-pancreatic diversion and duodenal switch?
Malabsorptive bariatric surgery. Stage one is the same as sleeve gastrectomy excess stomach is removed. The small intestine is then divided into two limbs; • The enteric limb for food only.
• The biliary limb which takes the digestive juices from the pancreas and bile duct.
The food therefore only meets the digestive juices just before the cecum.
What are the cons of bilio-pancreatic diversion and duodnal switch?
120g of protein is needed per day. Malnutrition is a large problem and is technically the most demanding.
What is Laparoscopic gastric bypass?
Combined bariatric surgery. The stomach is bypassed through the use of the ilium and a small stomach pouch.
Which form of bariatric surgery causes 'Dumping Syndrome' and what is it?
Laprioscopic gastric bypass, sweating and nausea after high sugar intake.
What are the 2 year excess weight loss figures for the four types of bariatric surgery?
• Laproscopic Gastric Banding - 55-60%
• Laproscopic Sleeve Gastrectomy - 60%
• Laproscopic bilio-pancreatic with duodenal switch - 90%
• Laproscopic gastric bypass - 75%
What are the three important subregions of the hypothalamus?
Lateral, Ventromedial and Acruate nucleus.
Which subregion of the hypothalamus generates satiety? And what stimulus does it respond to?
Ventromedial hypothalamus, Increase in blood glucose.
Which subregion of the hypothalamus generates hunger and what stimulates it?
Lateral hypothalamus, Decrease in blood glucose.
How does the hypothalamus know your weight?
Level of body fat is know as adiposity. Leptin is an adipostat which are produced by the adipose tissue. Circulating levels of adipostat are proportional to body fat.
Which gene produces Leptin?
The Ob gene.
What does the Ob gene produce and what occurs when there is no Ob gene?
Leptin, Eat voraciously and gain weight.
Where does leptin primary act?
The arcuate nucleus of the hypothalamus.
Leptin primarily acts on the arcuate nucleus of the hypothalamus, what occurs when the leptin level falls?
Food intake goes up, energy expenditure down, parasympathetic activity up.
Leptin primarily acts on the arcuate nucleus of the hypothalamus, what occurs when the leptin level rises?
Food intake reduces, energy expenditure increases, sympathetic activity increases.
What is the physiology when high levels of leptin are detected?
Causes the production of anorexigenic peptides by the arcuate nucleus these inhibit feeding behaviour. These are Alpha-melanocyte stimulating hormone (Alpha-MSH) and CART.
What is the physiology that occurs when low levels of leptin are detected?
Causes the production of Orexigenic peptides by the arcuate nucleus. Neuropeptide Y and Agouti-related peptide. These activate feeding behaviour.
What are the two anorexigenic peptides? Where are they produced and in response to what?
Alpha-MSH and CART, the arcuate nucleus of the hypothalamus in response to high levels of leptin.
What are the two orexigenic peptides? Where are they produced and in response to what?
Neuropeptide Y and agouti-related peptide, the arcuate nucleus of the hypothalamus in response to low levels of leptin.
Which receptor do aMSH and AgRP bind to?
Melanocortin receptor, aMSH activates it whilst AgRP blocks it.
The Melanocortin receptor is activated by one peptide and blocked by another, what are they?
aMSH - Activates
AgRP - Blocks
What role does insulin take in controlling apetite?
Insulin acts directly on the hypothalamus to cause the arcuate nucleus to produce anorectic pepties (aMSH) this inhibits feeding.
What is Grehlin?
Grehlin is produced by the stomach, high levels increases hunger. The levels rise before meals and falls after meals.
The stimulation of which nerve causes satiety?
The vagus nerve.
The vagus nerve is activated in which two ways by the stomach to produce satiety?
Stomach distension and the hormone cholecystokinin (CCK).
What is the hormone CCK?
Cholecystokinin, produced by gut epithelia in response to food.
What is serotonin?
Neurotransmitter and a mood regulator.
What is the role of serotonin in apetite control?
Dopamine is released by the brain in response to food and increases apetite. Serotonin activates receptors on dopamine producing cells resulting in a decreased apetite.
Sibutramine has now been withdrawn but how did it help manage apetite?
Sibutramine is a serotonin and noradrenaline reuptake inhibitor. So it both increased feelings of satiety and reduced metabolic supression that occurs with weight loss.
What is the 'reward circuit'?
Rewards stimulate the release of dopamine, palatable foods are very rewarding, this causes us to be highly motivated to consume them.
What is homeostasis?
The maintenance of a stable internal environment.
What is metabolism and what are the two aspects of it?
Degredation and synthesis of molecules. Anabolism and Catabolism.
What is anabolism?
Building up of complex molecules required for life.
What is catabolism?
The breakdown of complex nutrients into simple molecules.
What are the two main electron carriers?
NAD+ and NADP+
NAD+ is an electron carrier, during which metabolic process is it utilised?
NADP+ is an electron carrier, during which metabolic process is it utilised?
Where is glycogen stored?
Liver (and muscles)
What is the basal metabolic rate?
This is the energy required by an individual at physical, emotional and digestive rest.
What factors increase basal metabolic rate?
Hyperthyroidism, exposure to cold, regular exercise, disease, fever.