Lecture 9: Diet and Renal Disease Flashcards
What is an AKI? Characteristics?
Acute Kidney Injury
- Decreased eGFR
- Abnormal volume status
- Electrolyte imbalances
- Buildup of waste products in blood
What is heavily affected in AKI patients? What do they need?
Accelerated protein breakdown, not suppressed by exogenous protein provision.
Need more protein intake for prolonged AKI.
What is CKD? Characteristics?
- Persistently abnormal kidney function by either eGFR < 60 or structural/functional markers of kidney disease.
What are the stages of CKD and how are they determined?
- Stage 1: eGFR > 90 with kidney damage
- Stage 2: eGFR 60-90 with kidney damage
- Stage 3a: eGFR 45-59
- Stage 3b: eGFR 30-44
- Stage 4: eGFR 16-29
- Stage 5: eGFR <=15
Can also be staged by presence and amount of proteinuria
What are the two main causes of CKD?
- HTN
- DM
How are metabolic pathways affected in CKD?
- Altered feedback mechanisms
- Altered protein homeostasis and catabolism
- Altered energy homeostasis
- Altered nutrient metabolism
How do we manage protein intake for CKD patients?
- Adults: restrict protein intake for chronic CKD.
- Pediatric: monitor closely, restriction may cause nutritional deficiencies.
What kind of proteins are recommended if you have CKD?
Plant-based proteins.
Why are animal proteins not recommended?
- Much more bioavailable phosphate
- Higher potential acid load (PRAL)
When do we begin protein restriction recommendations in terms of CKD stages?
- Stage 1-2 (GFR > 60), no need for restriction, simply aim for 0.8g/kg/day.
- Stage 3-5 (eGFR < 60), restrict intake to 0.6-0.8 with increasing proportion of plant-based proteins.
How do you treat stage 5/ESRD on dialysis in terms of protein intake?
Increased protein intake, especially if on peritoneal dialysis.
They have increased metabolic demands.
What is the PLADO diet?
Plant-Dominant Low Protein Diet
- Protein intake: 0.6-0.8
- > 50% of protein intake from plants
- Sodium < 4g/day, < 3g if htn or edema
- High fiber
- Normal caloric intake
What electrolyte abnormality could present with a PLADO diet?
Hyperkalemia
What other diet is good for CKD that is low protein?
Very low protein diet with supplementation (good outcomes)
- Protein intake down to 0.23-0.43.
- Supplementation with AAs, ketoacids, and hydroxy acids to reduce nitrogenous waste load.
What are CKD patients prone to in terms of energy intake states?
Anorexia and Cachexia
What cardiac disease may contribute to CKD? How would we counsel a patient regarding it?
Atherosclerosis.
Avoid sat/trans fats, eat more PUFAs and MUFAs, esp omega-3.
Why is dietary fiber good for CKD patients?
- Promotes fecal nitrogen excretion
- Lower inflammation
- Better mortality
- 25-30g/day
Why do we want lower sodium in CKD patients?
Contributes heavily to HTN, which contributes and worsens CKD.
Aim for 3-4g/day or < 2300mg
How much fluids should CKD patients drink?
1.5L on average, with 1.0L if complicated.
Why does hyperkalemia occur in CKD? How can we prevent it?
- Occurs because late-stage CKD patients can’t excrete potassium.
- Eating low-potassium foods or boiling them is best to reduce potassium intake.
- Aim for < 3g/day.
What blood pH condition may occur in CKD? Why?
Metabolic acidosis, due to inability to excrete H+ and resorb HCO3-.
PRAL also contributes, especially if animal protein.
How do we reduce acid levels in CKD?
- Sodum bicarb supplementation.
- Eat fruits/veggies
What other mineral should CKD patients be restricted in terms of intake?
Phosphorus, < 800mg/day if stages 3+.
What vitamin supplementation is recommended in all stages of CKD?
Vitamin D, which will also boost calcium.
What other vitamins/minerals are CKD patients commonly deficient in?
- B vitamins
- Vitamin C
- Iron
What metal should we avoid eating in CKD?
Aluminum-based medications
What trace mineral, when ingested, may help with lipid levels in CKD?
Carnitine
What two trace elements are also deficient in CKD patients on dialysis? What is the recommendation regarding supplementation of them?
Zinc/Selenium.
Not recommended to routinely supplement.
