Diet and Renal diseases Dr. Reham Khresheh 20/09/2018

OBJECTIVES After studying this chapter, you should be able to: Describe, in general terms, the work of the kidneys Discuss common causes of renal disease Explain why protein is restricted for renal clients Explain why sodium and water are sometimes restricted for renal clients Explain why potassium and phosphorus are sometimes restricted for renal clients 20/09/2018

Loss of renal function profoundly affects metabolism, nutritional status, and nutritional requirements Nutrients most affected are Protein Calcium Phosphorus vitamin D fluid, sodium potassium 20/09/2018

Uremic syndrome a cluster of symptoms related to the retention of nitrogenous substances in the blood 20/09/2018

Uremic syndrome fatigue unpleasant nausea decreased mental acuity muscle twitches cramps anorexia unpleasant nausea vomiting diarrhea itchy skin gastritis GI bleeding 20/09/2018

Pre-end stage renal disease period of renal failure when renal function is impaired dialysis or transplant is not yet required also known as renal insufficiency 20/09/2018

End stage renal disease (ESRD) severe stage of chronic renal failure (CRF) requires life sustaining treatment with either dialysis or a kidney transplant BUN may be as high as 150-250 mg/dL 20/09/2018

NUTRITION THERAPY 1. Protein Protein restriction is cornerstone of dietary treatment for pre-end stage, which helps preserve nephron function & potential to lessen renal workload and slow disease progression Too much protein increase BUN & the symptoms of uremia Too little protein results in body protein catabolism, which increases serum potassium & BUN level & protein malnutrition as evidenced by low albumin levels. 20/09/2018

NUTRITION THERAPY (cont’d) Low albumin is a strong predicator of mortality in pts starting dialysis The most severe level of protein restriction is for renal insufficiency without dialysis Recommended daily intake of protein is 0.6-0.8 g/kg It is recommended that 60% of total protein be from high biologic sources such as eggs, milk, yogurt, cheese, meat, fish, poultry, soy (because they promote reuse of circulating nonessential amino acids for protein synthesis & by doing so minimize urea production) 20/09/2018

NUTRITION THERAPY (cont’d) 2. Calories Adequate calories are needed to prevent weight loss & body protein catabolism. Taking in too few calories can have the same effect as eating too much protein: BUN levels rise because body proteins are broken down for energy Daily intake is 35 cal/kg for adults who are not undergoing dialysis 20/09/2018

NUTRITION THERAPY (cont’d) Pure sugar & pure fats are recommended for calories because they do not provide protein Children with renal failure experience growth failure. Aggressive nutrition therapy is needed, calcium supplements, vitamin D & phosphate may be used to promote calcium uptake by the bones 20/09/2018

NUTRITION THERAPY (cont’d) 3. Sodium & fluid: If the client does not have edema, hypertension or signs of CHF, increasing the sodium intake as tolerated may improve GFR If blood pressure & serum sodium levels are normal & edema does not occur, fluid intake can be exceed 24-hour urine output by 500 ml(fluid deficit) Typical fluid allowance range from 500 to 3000 ml/day 20/09/2018

NUTRITION THERAPY (cont’d) 4. Potassium Most clients with renal insufficiency & those undergoing peritoneal dialysis do not need to restrict potassium intake Potassium restriction of 2-3 g/day is recommended for hemodialysis clients with hyperkalemia Clients who are taking potassium-wasting diuretics may need more potassium to avoid hypokalemia 20/09/2018

NUTRITION THERAPY (cont’d) 5. Phosphorus & Calcium: The metabolism of calcium, phosphorus, & magnesium is altered, resulting in hyperphosphatemia, bone demineralization, bone pain, & calcification of soft tissue (eye, skin, heart, lungs, blood vessels) Renal osteodystrophy may be prevented by the following measures: limiting phosphorus intake providing vitamin D supplements providing calcium supplements avoiding aluminum which may cause encephalopathy & osteodystrophy 20/09/2018

NUTRITION THERAPY (cont’d) 6. vitamins Deficiency of water soluble may caused by inadequate intake related to anorexia or dietary restriction; altered metabolism related to uremia Water soluble vitamins are recommended for both nondialyzed & dialyzed clients Except for vitamin D, supplement of fat soluble vitamins is not necessary. Vitamin A supplement is contraindicated (toxic) 20/09/2018

NUTRITION THERAPY (cont’d) 7. Trace elements Zinc supplements is recommended if a zinc deficiency is identified Iron & human erythropoietin are used to treat anemia 20/09/2018

Strategies to promote dietary adherence Encourage clients to weigh and measure foods Emphasize what to eat rather than food restrictions Encourage social support from family and friends Foster client’s perception of success and confidence Provide feedback on self-monitoring Encourage client to try low protein breads, cereals, cookies, gelatin, and pastas indicated whenever protein intake is restricted ensure that the protein consumed will be used for specific protein functions, not for energy requirements 20/09/2018

Strategies to relieve thirst Use ice or popsicles Suck on hard candy or mints Chew gum Frequent mouth rinsing with refrigerated water Control blood glucose levels, as appropriate Try frozen grapes Use small glasses instead of large ones Apply petroleum jelly to the lips 20/09/2018

Impaired calcium metabolism results with loss of renal function: faulty vitamin D metabolism impaired intestinal absorption hyperphosphatemia A high calcium intake from food is not achievable when phosphorus is restricted 20/09/2018

Dialysis dietary restrictions can be liberalized high protein intake is recommended to compensate for protein lost through the dialysate 20/09/2018

Acute Renal Failure (ARF) ARF represents an even greater nutritional challenge than CRF Protein, sodium, potassium, phosphorus, and fluid are adjusted according to lab data use of dialysis renal function drug therapy 20/09/2018

Immunosuppressant therapy Renal transplant patients alter diet to lessen side effects of immunosuppressant therapy Steroids cause hyperglycemia sodium retention weight gain potassium depletion loss of calcium from the bones gastrointestinal upsets 20/09/2018

Dietary measures for treatment of clients on dialysis 35 – 50 kcal/kg/day to prevent protein catabolism 500 – 1.500 ml fluid/day 2-3 mg/day potassium 100 mg folate 10 mg pyridoxine (vitamin B6) 100 mg ascorbic acid RDA of other water soluble vitamins 15 mg iron calcium supplement up to 1,200 mg/d 20/09/2018

UROLITHIASIS the precipitation of insoluble crystals in the urine leads to the formation of the stones (calculi) 80% of stones contain calcium, composed of calcium oxalate 10% of stones composed of uric acid Calculi may result from low urine volume 20/09/2018

UROLITHIASIS (cont’d) Certain dietary factors are implicated in stone formation: Animal protein: make the more acidic, which promote calcium excretion & inhibits calcium reabsorption. Also considered the major source of purine, the precursors of uric acid. High levels of uric acid make calcium oxalate less soluble, thereby increasing the risk of calcium stone formation Sodium: because the body rids itself of excess sodium through the urine, the greater the sodium intake, the greater the level of urinary sodium. High urinary sodium increases urinary excretion of calcium & uric acid & increases calcium mobilization from bone 20/09/2018

UROLITHIASIS (cont’d) Oxalates: certain foods are rich source of oxalates, including nuts, chocolates, dark green leafy vegetables, tomato sauce & jam. So restriction dietary oxalates reduce urinary oxalate levels but not prevent stone formation Calcium: calcium intake from diary products may be associates with high urinary calcium levels & stone formation. Dietary calcium may bind with dietary oxalates in the intestines, forming an insoluble compound that the body cannot absorb. 20/09/2018

Nutrition Therapy Increase fluids intake & thereby dilute the urine Daily fluid intake 2.5 – 3 L is recommended Fluid intake should be increased in hot weather & exercise Water should be consumed before bedtime because urine becomes more concentrated at night 20/09/2018

Nutrition Therapy (cont’d) For clients with hypercalciuria: Increase fluid intake to increase urine output to 2 L/day Limit animal protein, & sodium to 2 g/d, & oxalate Vitamin B6 supplements reduce oxalate formation Avoid Vitamin C, because the body can synthesize oxalate from it Maintain adequate calcium intake 20/09/2018