Malnutrition + Overnutrition Flashcards
what are the 4 disease related caused of malnutrition?
decreased intake
impaired digestion/absorption
increased nutritional requirements
increased nutrient losses
what common symptoms of disease cause increased nutrient losses?
vomiting and diarrhoea
what are the 9 main psychosocial causes of malnutrition?
inapproptiate food provision lack of assistance poor eating environment lack of cooking skills/facilities self neglect bereavement inability to access food deprivation loneliness
what are the 9 major adverse effects of malnutrition?
impaired immune responses impaired wound healing reduced muscle strength and fatigue cardio-resoiratory weakness immobility water and electrolyte disturbances impaired thermoregulation menstrual irregularities psycho-social effects
weight loss is a symptoms for what major 8 GI diseases?
coeliacs diseasse crohns disease colorectal cancer gastric cancer oesophageal cancer intra abdominal infection impaired GI motility acute liver disease
what is the aim of the MUST score?
a screening tool to identify adults who are malnourished or at risk of malnourisment
when must patients be nutritonally screened using MUST?
within 1 day of admission
what is Step 1 of MUST?
BMI score
above 20 = 0
18.5-20 = 1
below 18. 5 = 2
what is Step 2 of MUST?
weight loss score (unexplained weight loss in past 3-6 months) less than 5 percent = 0 5- 10 percent = 1 greater than 10 percent = 2
what is Step 3 of MUST?
if patient is acutely ill AND likely to be no nutritional intake for >5days = 2 points
what is Step 4?
add scores from step 1, 2 and 3 to calculate overall risk of malnutrition
0 = low risk
1 = medium risk
2+ = high risk
how do you calculate BMI?
mass (kg)/
height^2(m)
what is the 4 step pyramid of nutritional support?
food
oral nutritional supplements
enteral nutrition
parenteral nutrition
what is refeeding syndrome?
occurs when previously malnourished are fed with high carbohydate loads
this causes a rapid decline in electrolytes and an increase in extracellular volume which results in organ dysfunction
why is there an increase in extracellular volume (oedema) in patients with refeeding syndrome?
due to salt and water retentsion
what are the main metabolic features of refeeding syndrome?
hypokalaemia hypophosphataemia hypomagnesaemia altered glucose metabolism fluid overload
what are the physiological features of refeeding syndrome?
arrhythmias altered level of consciousness seizures respiratory failure cardiovascular collapse death
how do you prevent refeeding syndrome in moderate risk patients?
introduce nutritional support at a maximum of 50% of requirements for first 8 hours, increase nutritional support after 48 hours if monitoring reveals no problems
what must you do to prevent refeeding syndrome in high risk patients?
rehydrate carefully and supplement potassium, magnesium, phosphate, calcium, thiamine and vit B
start feeding at 5-10kcal/kg/day
what are the BMI categories?
below 18.5 = underweight 18.5- 24.9 = normal 25- 29.9 = overweight 30- 39.9 = obese 40+ = morbidly obese
what are the 9 main consequences of obesity?
diabetes heart disease NAFLD repiratory disease stroke osteoarthriris some cancers (uterus, breast, prostate, colon) gallbladder disease dementia
what s the effect that long-term obesity has on brain-reprogramming?
brain becomes to view extra weight as normal and dieting as a threat to body survival
(so defends new weight by switching on compensatory mechanisms to maintain energy expenditure)
what part of the hypothalamus seems to be associated with decreased energy expenditure?
(ie causes obesity)
lateral hypothalamus
what part of the hypothalamus seems to be associated with increased energy expenditure?
(ie causes leaness)
ventromedial hypothalamus
what are the 3 basic concepts which underlie the control of energy intake and body weight?
- satiety signalling (short term)
- adiposity negative feedback signalling (long term)
- food reward
what is satiation?
sensation of fullness generated during a meal
what is satiety?
period of time between termination of one meal and the initiation of the next
what type of feedback occurs when satiation signals increase during meal to limit meal size?
negative feedback
what are 5 gut satiation signals?
cholecystokinin (CCK) peptide YY (PYY) glucagon-like peptide (GLP-1) oxyntomodulin (OXM) obestatin
what is ghrelin?
a gut hunger signal secreted from oxyntic cells in stomach
when do levels of ghrelin increase?
before meals
when are levels of ghrelin raised?
fasting
hypoglycaemia
what 2 hormones report fat status to the brain?
leptin
insulin
where is leptin made and released from?
fat cells
where is insulin made and released from?
b-cells in pancreas
what happens to the levels of leptin and insulin as fat storage increases?
hormone levels in the blood increase
what is the response of the brain to increased insulin and leptin?
eat less and increase energy burn
in the obese state what happens to leptin and insulin control mechanisms for reporting fat status?
they malfunction
how are peripheral actions different to central actions of insulin?
insulin peripherally cause build up of fat/glycogen etc (anabolic)
insulin in the brain causes break down of fat (catabolic)
why doesnt the high levels of leptin (that accompany high levels of fat storage) in obese people cause catbolism of fat?
severe leptin resistance present in most ovese individuals
what is the main drug for treatment of obesity?
orlistat
what is the function of orlistat?
inhibits pancreatic lipase to decrease lipid absorption
what are the side effects of orlistat?
cramping
severe diarrhoea
vitamin deficiency (need to take vitamin supplements)
why isn’t orlistat efective over long term?
rebound weight
what is liraglutide?
a glucagon-like-peptide 1 receptor agonist
compare dosing of liraglutide for type 2 diabetes to dosing for weight loss?
higher doses used for weight loss than diabetes
how is liraglutide administered?
injections
what is the most effect therapy for obesity?
bariatric surgery
