Transcript Dietary Issues in Renal Complications Ulrich Wahl

Dietary Issues in Renal
Complications
Ulrich Wahl, Tamworth, 2010
Progression of Renal disease
Stage
GFR
Description
1
90+
Normal kidney function but urine findings or structural
abnormalities or genetic trait point to kidney disease
Observation, control of blood pressure.
2
60-89
Mildly reduced kidney function, and other findings (as for stage
1) point to kidney disease Observation, control of blood pressure
and risk factors.
3
30-59
Moderately reduced kidney function Observation, control of
blood pressure and risk factors.
4
15-29
Severely reduced kidney function Planning for endstage renal
failure.
5
<15 or on
dialysis
Very severe, or endstage kidney failure (sometimes call
established renal failure)
Weight Reduction in Kidney Disease
CARI Guidelines
• a. Obese patients with proteinuric
nephropathy should be encouraged to reduce
their weight while ensuring adequate
nutrition.
• b. The potential metabolic and cardiovascular
benefits that may arise from weight
reduction in obese patients should not be
ignored
Weight Reduction in Kidney Disease
• Weight Loss:– Control BP
– Control Lipids
– Control blood glucose in Type 2 diabetes
– Reduces urinary protein excretion (weak evidence)
Goal should be modest sustained weight loss and
risk factor management rather than return to ideal
or normal weight
Dietary Protein Restriction
• A protein-controlled diet consisting of 0.75–
1.0 g/kg/day, is recommended for adults with
chronic renal disease (CKD). The
administration of a low protein diet (<= 0.6
g/kg/day) to slow renal failure progression is
not justified when the reported clinically
modest benefit on glomerular filtration rate
(GFR) decline is weighed against the
concomitant significant declines in clinical and
biochemical parameters of nutrition.
Sodium Restriction
• Dietary salt is important in blood pressure control in both
hypertensives and normotensives and therefore expect
that this could be protective in the development and
progression of CKD.
• Low salt intake enhances and high salt intake reduces the
antiproteinuric effect of ACE inhibition.
• Urinary albumin excretion is reduced by lowering dietary
salt.
National Evidence Based Guideline for Diagnosis, Prevention and Management of Chronic Kidney Disease in
Type 2 Diabetes 2009
Potassium
• Important in stage 4 and 5. Not usually
necessary in stage 3
• Used on a case by case basis if serum K > 6.0
mmol/l
Phosphate
• Only necessary in stage 4 and 5
• Never used on its own
• Aim for 800 to 1200 mg per day
Perspectives on Sodium
• A teaspoon of salt weighs about 5 grams
• Of that 1.983 grams is sodium (about 2000
mg)
• Many of the guidelines for a low Na diet aim
for 100 mmol per day
• This equals 2300 mg from ALL sources
Perspectives on Sodium 2
• You can achieve this level by:– No added salt at the table or in cooking
– Limiting packaged foods and restricting those you
buy to 200mg of Na per 100 g
– For a more severe restriction limit any packaged
food to 120 mg per 100g
Perspectives on potassium
• When needed the aim is to limit K to
1mmol/kg IBW per day
• It is often not listed on food labels therefore
the dietitian must provide the information
• Serum K can be raised in the short term by
other transient medical conditions eg acidosis.
Perspectives on potassium 2
•
•
•
Potassium is water-soluble
Soak or boil vegetables to reduce potassium
before adding to the meal or serving as a
side dish
Make sure you discard the water
Perspectives on potassium 3
•
For wet dishes like stews and casseroles, the
potassium will be mainly in the fluid
•
Use a slotted spoon to minimise the fluid
you serve yourself
Perspectives on Phosphate
• Phosphate is rarely listed on food labels
• Phosphate metabolism interacts with Calcium
levels interacts with the parathyroid interacts
with bone turnover.
• Often need phosphate binders as well as diet
to limit serum PO4
• Patient must be educated to take binder when
they eat higher phosphate foods
Perspectives on Phosphate 2
• Limit PO4 to:• To prevent tissue calcification
• To prevent calciphylaxis (thrombosis /
necrosis)
• To prevent hyperparathyroidism
(which causes further bone PO4 leaching )
• To prevent itch
Perspectives on Phosphate 3
• Low phosphate diet = low calcium (may need
calcium supplementation)
• If they take iron or calcium supplements these
must be taken between meals if on phosphate
binders
• Many protein foods high in phosphorous
Dialysis
Nutrient
HAEMODIALYSIS
PERITONEAL
DIALYSIS
Protein
Increased
Increased
Calories
Increased as weight
loss is common
Decreased as weight
gain is common
Sodium or salt
Continue on no added
salt diet
Continue on no added
salt diet
Phosphate
Restricted
Restricted
Potassium
Usually restricted
Not usually restricted
Fluid
500mls + urine output
750mls + urine output
Fibre
Need to watch high
potassium sources
Increased.
Dialysis Issues
• HbA1c values not accurate
• In peritoneal dialysis the fluid is often a
dextrose solution. There can be considerable
carbohydrate absorption from this fluid (180
g/day)
Malnutrition
• In stage 4 and 5 appetitive often suppressed
• This combined with restrictions can lead to
malnutrition. Must nutritionally assess
patients.
• Often find that > 30% fat intake required and
/or use of renal supplements to achieve
adequate nutrition.
Some practical stuff