Nutrition support 2 Flashcards
What is the definition of anorexia?
Anorexia is the loss of the desire to eat associated with reduced food intake.
Has a neuro-hormonal origin
Link with depression and altered taste and appetite levels.
What is the definition of starvation?
Relative lack of food including reduced REE and decrease muscle catabolism.
REE will be reduced by 10-15% as a response of the body trying to conserve energy.
Metabolic adaptation for survival and protect muscle metabolism
What is cachexia?
A clinical syndrome characterised by altered metabolism, anorexia, early satiety, severe weight loss, weakness, anaemia and oedema Associated with poor response to treatment and poor quality of life.
Increase in mortality and morbidity
Deficiency of anabolic hormones and excess of catabolic (breaking down)
Linked with lots of inflammatory responses in the body, e.g release of cytokines in cancer TNF, IL.
Difficult to blunt the catabolic and inflammatory response occurring in the body.
Present is most terminally ill cancer patients and accounts for 20% of deaths
- greater in tumours of GI tract and lung than solid tumours (e.g. breast) and haematological malignancies
What is the dietetic goals for someone with cancer cachexia?
Maintain and prevent further weight loss
Attempt to meet nutritional requirements
Weight gain may not be realistic
Multimodal treatments –> work with other discipline
Look at staff limitations
What is sarcopenia?
Reduced muscle mass, muscle performance and strength
Can lead to frailty –> increase in fall risk and independence loss
Natural process that occurs with ageing
Can be prevented/ slowed down by assessing activity levels and protein intake (some research looking at vitamin D)
Obesity sarcopenia –> high adipose tissue with low muscle mass can be due to activity levels, ageing, diet or other disease.
- increasing muscle mass reduces mortality and morbidity risk
What is the criteria for cancer cachexia in older adults?
Dunne at al 2019, comprehensive review
- > 5% weight loss in the previous 6 months
OR
2% weight loss and one of the following
- Body mass index <20kg/m2
- Evidence of muscle depletion
What is the criteria for sarcopenia in older adults?
Dunne at al 2019, comprehensive review
- Diagnosis of sarcopenia is probable with low muscle strength
- Diagnosis is confirmed with low muscle quality
- Reduced physical performance along with reduced muscle strength and muscle quality/ quantity represents severe sarcopenia
How does cancer cachexia effect fat metabolism?
- Increased lipolysis (fat store breakdown)
- Decrease lipoproteins lipase activity (hypertriglycaemia)
- Increased oxidation of free fatty acids and glycerol (not suppressed by glucose so differs from starvation) –> more fat being broken down to reduce energy but not halted by giving carbohydrates and glucose
- Increased lipid mobilisation secondary to action of a tumour catabolic factor - LMF (lipid mobilising factor)
Constantly mobilising fat stores instead of making them
How does cancer cachexia effect protein metabolism?
- Increased whole body protein turnover (increased muscle protein breakdown, increased hepatic protein synthesis, decreased muscle protein synthesis) –> lean muscles targeted and broken down.
- Reduced physical activity may be a factor in suppression of protein synthesis
- Ubiquitin-proteasome proteolytic pathway is the main mechanism for increase in muscle catabolism –> usually tightly regulated, however is cancer something goes wrong and ubiquitin binds to proteins and labels them for destruction
- Simple nutritional supplementation is not effective in preventing muscle catabolism.
Catabolism outweighs building up
Low muscle mass and sarcopenia have a higher risk of mortality, morbidity and reduced positive outcomes from treatment.
What is the Ubiquitin-proteasome proteolytic pathway?
Link to cancer? Cachexia?
- Ubiquitin-proteasome proteolytic pathway is the main mechanism for increase in muscle catabolism –> usually tightly regulated, however is cancer something goes wrong and ubiquitin binds to proteins and labels them for destruction
Can protein breakdown be prevented through supplementation?
Even with adequate nutrition, protein breakdown can still occur which may require medications to reduce inflammation, stimulate appetite. Patients with lower muscle mass and sarcopenia have a higher risk of mortality.
Simple nutritional supplementation is not effective in preventing muscle catabolism
What has research found about the effectiveness of nutritional interventions on malnutrition and cachexia?
Baldwin, 2015
- Limited evidence of benefit to nutritional and clinical outcomes but some improvements to aspects of quality of life
- The presence of cachexia in patients with cancer might explain the limited efficacy of simple oral cancer nutritional interventions which lack a component designed t address metabolic abnormalities with cachexia
- Novel strategies combining nutritional support with therapeutic agents designed to down-regulate the metabolic aberrations have failed to demonstrate consistent benefits and results of multimodal treatments combining several interventions are awaited.
How is REE effected with cancer?
Depends on what cancer the patient has. Response related to tumour type
- Lung/ pancreatic = hypermetabolic –> increase energy expenditure
- Gastric/ colorectal = normometabolic
Heterogenous response may increase, decrease or have no affect on REE
If there is a 12% increase is REE that results in a 1-2kg weight loss per month
How does weight loss have an effect on cancer patients?
Studies have shown that cancer patients who lose weight (involuntary) have a reduced rate of survival
Patients who have had a >10% weight loss have reduced impact of treatment from chemotherapy
What types of cancer/ tumour is hypermetabolic?
Lung, pancreatic
Hypermetabolism is related to pro-inflammatory cytokines and neuroendocrine responses and is frequent in advanced non-small cell lung cancer (80% of lunger cancer diagnoses)
