Nutrition Flashcards
What are the classifications of CKD, and how is each stage managed?
Stage 1 - Normal function: CKD risk factors such as hypertension, diabetes, and obesity
Stage 2 - Mild decrease in GFR: reduce CKD risk factors by managing diabetes, weight and hypertension
Stage 3 - Moderate decrease in GFR: Treat the complications of CKD by controlling ureamia and fluid restriction of needed. Also managing diabetes and hypertension.
Stage 4 - Severe decrease in GFR
Stage 5 - End stage : both (stage 4 and 5) treated by looking for kidney replacement as well as all the above; preventing malnutrition and electrolyte imbalances
What are the aims of nutritional intervention in the renal patient?
- Delay progression of CKD
- Minimise symptoms of ureamia (stage 4 and 5)
- Minimise effect of renal disease on blood biochemistry and fluid status
- Identify and treat malnutrition
What are uraemic symptoms?
Due to urea in the blood. Main uremic symptoms include:
- Tiring easily, weakness
- Anorexia and nausea
- Muscle cramps
- Bad taste in mouth
How is protein intake relevant to CKD patients?
In the past, low protein diets helped with uraemic symptoms. This is only a symptomatic treatment and does not affect disease itself much. A cochrane review showed that it did actually reduce progression in one year.
What is the recommended protein intake to reduce uraemic symptoms (aim 2)
0.75g/kg of ideal body weight (1.2 on PD; 1.4 on HD)
What are the main biochemical and fluid effects of CKD that can be controlled by nutrition (aim 3)?
- hyperphosphataemia
- hyperkalaemia
- oedemea
How can nutrition delay the progression of CKD (aim 1)?
To delay renal function deterioration:
- Optimise glycemic control in diabetes (HbA1c
How can nutrition correct hyperphosphataemia?
Rarely done by reducing intake alone as phosphates are in many foods. Phosphate binders can be taken with food to reduce phosphate absorption.
What is the problem caused by hyperphosphataemia?
The high phosphate causes osteoporosis and calcium deposits and calcification. Calciphylaxis are chronic non-healing wounds.
What foods are high in phosphate?
- Diary products
- Seafood
- Nuts
- Chocolate
- Hard cheese and processed cheeses
What are the non-renal causes of hyperkalaemia?
Diet, medications , constipation, blood transfusions, hyperglycaemia and acidosis can also cause it.
How can nutrition correct hyperkalaemia?
Avoiding foods with a high potassium content e.g fruits and spinach.
Change the way they are prepared - e.g potassium will wash away with water if vegetables are boiled.
How can nutrition correct oedema?
fluid restriction and reducing salt intake
What tips would you advise to reduce salt intake?
- Do not add salt at the table
- Reduce salt in cooking
- Add herbs and spices
- Reduced processed foods
- Beware of salt substitutes such as LoSalt (not better)
What are the three sources of malnutrition in the renal patient?
- Disease related (uraemia, anorexia, acidosis)
- Treatment related (infections, dietary restriction, nutrient losses etc)
- Person related (depression, family support)
What are the BMI values for Obesity?
Non-asians:
- Obese = 30-35 kg/m2
- Severe Obesity = 35-40
- Morbid Obesity = +40
Asians:
- Obese = 25 - 30
- Severe obesity = +30
What are the problems with BMI?
- does not differentiate muscle and fat
- not account for distribution of body fat (low BMI but high waist circumference)
How do you measure waist circumference?
Measure at mid-point between the lowest rib and the iliac crest.
Why is waist circumference a better measure than BMI?
Abdominal obesity is a big risk. Excess visceral fat effects glucose metabolism and increases insulin release. Also has potential impact on liver metabolism.
What does excess visceral fat cause?
- Deterioration of lipid profile
- Impaired insulin sensitivity (have to produce a lot more insulin than others)
- Increased susceptibility to thrombosis
- Increased inflammation markers
- Impaired endothelial function
How is obesity linked to energy inbalance?
Epidemiological studies shows that there is no relationship between energy intake and obesity.
However, there is a much stronger link between inactivity and obesity
However, these studies are very limited
What are the effects of obesity?
- Ischaemic heart disease (along with hypertension, coronary thrombosis, congestive heart failure)
- Type 2 Diabetes
- Cancer (breast, endometrial, somach and colon)
- Osteoarthritis
- Mental health issues
What are the components of daily energy expenditure?
- Resting metabolic rate (50-70%)
- Thermogenesis (5-15%)
- Physical activity (20-40%)
Why is obesity common?
- cheap food
- thrifty genes