Undernutrition Flashcards
nutritional aspects of disease
aetiological
consequences
aetiological aspect of disease
disease caused by nutrition
Diseases of nutritional deficiency or excess
consequences aspect of disease
Impact of disease on nutrition status
what can undernutrition be?
generalised
specific
primary
secondary
generalised nutrition
deficiency of calories
specific nutrition
deficiency of an essential nutrient
primary undernutrition
related to the diet
secondary undernutrition
related to an illness or condition
consequences of undernutrition (Also relates to generalised undernutrition)
(Example of primary undernutrition)
Protein-Energy-Malnutrition affects 400+ million people worldwide.
Affects every organ and system within the body
- e.g. ability to fight infection
forms of PEM
dry
wet
dry PEM
Marasmus (no oedema, general)
Severe calorie and protein deficiency
wet PEM
Kwashiorkor (oedema, specific)
Protein deficiency with adequate calories,
generally from carbohydrate
(Ghanaian 1st – 2nd child)
Low protein reduces synthesis of blood proteins, particularly albumin. Low protein in the blood has an osmotic effect and causes water to diffuse into the interstitial fluid (oedema)
energy balance equation
energy intake = energy expenditure +- energy stored
causes of undernutrition
- reduced delivery of nutrients to the gastrointestinal system
- increased demand for nutrients
- inability for gastrointestinal system to absorb nutrients
- reduced delivery of nutrients to the gastrointestinal system
Decreased food availability
Mechanical - E.g. oesophagus doesn’t work, not physically able to open/get to food
Functional (neurological) - anorexia nervosa/stroke - affected ability to swallow
Not enough energy into system - neg energy balance
- increased demand for nutrients
Physiological
Pathophysiological - Increased metabolic rate in burns, trauma, infection, cancer
E.g. pregnancy, increase energy requirements and demand
- inability for gastrointestinal system to absorb nutrients
Intrinsic problem
- Coeliac disease, diarrhoea
Post-surgery
- Part of bowel removed, reduce absorption capacity
example of cause: Cancer cachexia
Multifactorial syndrome characterised by an ongoing loss of skeletal muscle mass (with or without loss of fat mass) that cannot be fully reversed by conventional nutritional support and leads to progressive functional impairment. >5% weight loss in 6 months.
Acute phase proteins (APP) are released from the liver and signal a ‘stress’ response to breakdown muscle tissue for energy
The tumour needs energy, and energy is required to produce cytokines and acute phase proteins, and also gluconeogenesis§
Tumour - releases factors to allow body to release energy - increase met rate - increase demand for nutrients
Signals desire to eat - leads
to anorexia
undernutrition in cancer patients
at the time of diagnosis approximately 75% of cancer patients are undernourished, with a significantly lower lean mass than healthy controls.
Patients with highest weight loss are those with cancer of oesophagus, stomach, and larynx.
- Gastrointestinal system - impair function
Surgery/chemotherapy
- Anorexia, taste changes, dysphagia, nausea/vomiting, diarrhoea
- Trauma = increased met rate
- General feeling unwell reduces desire to eat
Nutritional support essential to increase the likelihood of completion of cancer treatment, enhance immune function, reduce mental and physical fatigue, and improve quality of life
dietician
state registered care professional
dietetics
use of diet in prevention/treatment of disease
aim of dietetics
modify nutritional intake via therapeutic/nutritional support
basic requirements of dietetics
1) Know normal nutritional requirements
2) Identify the nature of the disorder
3) Assess patient’s nutritional status and intake
- e.g. body composition, energy requirements, blood markers, food diary
4) Know the composition of foods, supplements and artificial feeds
5) Devise a meal plan / feed regimen
6) Monitor compliance and progression
7) Reassess and adjust as appropriate
case study: oesophageal cancer
50 year old man, heavy drinker for 30 years, BMI 17.5 kg/m2 - underweight
Diagnosed
Oesophagectomy Jejunostomy - part of oesophagus removed
Radiotherapy
enteral nutrition support
Provided when patients are expected to (or have) not received adequate nutrition for 7 days
Small bowel feeding administered with pump over 8-20 hours. Usually around 30 to 40 ml/h
Formulas come in a variety of energy densities, but most patients with standard fluid requirements will tolerate 1 to 1.2 kcal/ml
can’t give carb fat/protein - can’t be digested
refeeding syndrome
Phosphate is involved in the regulation of most metabolic pathways and is required for ATP resynthesis
oedema
water accumulation
the laws of thermodynamics dictate that e neg energy balance will result in reduced energy stores, but they don’t tell us how
Fat towards adipose tissue
and stored
After eating go to pos fat
storage into adipose tissue -
release insulin and prevent
FAs being released
Won’t go back to release fat if eat enough
If don’t eat enough fats released for tissue and not stored - back into neg adipose tissue flow
hypophosphataemia
low phosphate levels
what does form of PEM depend on?
protein-carbohydrate balance
what does energy undernutrition mean?
more time in postabsorptive state
what does starvation mean?
more time in fasting state
