Dietary Issues in Renal Complications Ulrich Wahl, Tamworth, 2010

Progression of Renal disease StageGFRDescription 190+Normal kidney function but urine findings or structural abnormalities or genetic trait point to kidney disease Observation, control of blood pressure Mildly reduced kidney function, and other findings (as for stage 1) point to kidney disease Observation, control of blood pressure and risk factors Moderately reduced kidney function Observation, control of blood pressure and risk factors 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 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 NutrientHAEMODIALYSISPERITONEAL DIALYSIS ProteinIncreased CaloriesIncreased as weight loss is common Decreased as weight gain is common Sodium or saltContinue on no added salt diet PhosphateRestricted PotassiumUsually restrictedNot usually restricted Fluid500mls + urine output750mls + urine output FibreNeed 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