Curated by Dr. Mara Cazzola
Epidemiology
Chronic kidney failure is a public health problem. Today, in the world, it is possible to record an incidence of more than 2 million new patients, but the WHO declares that this trend is constantly growing. In fact, it is estimated that in 2020, in China alone, there will be more than 1 million dialysis patients, while as many as 30 million will be suffering from kidney disease due to hypertension.
Metabolic alterations
A patient with stage V renal insufficiency is referred to as "uremic". Uremia is a term etymologically composed of two words: "ouron", from the Greek, which means urine and "haima", blood. The term refers to the metabolic and hydroelectrolytic alterations associated with the severity of this clinical condition. An uremic patient undergoes: alterations in the water balance, lack of sodium excretion, a possible appearance of hyperkalaemia, metabolic acidosis, hypertension, insulin resistance, changes in calcium / phosphorus metabolism, reduced chemotactic and phagocytic capacity of the immune cells, progressive anemia and cognitive disorders (such as memory loss, poor concentration and inattention) involving both the CNS and the PNS, alterations in the lipidemic picture concerning the concentrations of cholesterol, HDL, LDL, triglycerides and homocysteine, often aggravated by micro and macro albuminuria and by a negative nitrogen balance which frequently leads to a reduction in muscle mass.
Diet in the Uremic Patient
A uremic patient is destined for replacement therapy. Following the medical treatment suggested by your nephrologist, highly personalized and ad hoc, for these patients is essential in order to preserve a state of health as excellent as possible and optimize their quality of life. The moment in which replacement therapy is entered (the timing of entry into dialysis is decided by the doctor and the staff) the conservative one ceases, therefore the diet and eating habits of these patients undergo important and considerable changes.
The calorie-protein recommendations suggested by the feeding books and the European guidelines are different according to the dialysis method adopted (hemodialysis or peritoneal dialysis).
- For hemodialysis they suggest:
- 30-40kcal / per kg of ideal weight / day
- Protein 1.2g / per kg of ideal weight / day
- Phosphorus <15mg / g of protein
- Potassium <2-3g / day
- Sodium <2g / day
- Calcium: maximum level of 2 g / day
- Amount of liquids: residual diuresis + 500ml / day
- For peritoneal dialysis, on the other hand:
- 30-35 kcal / pro kg of ideal weight / day
- Proteins 1.2-1.5 / pro kg of ideal weight / day
- Phosphorus <15mg / g of protein
- Potassium <3 g / day
- Sodium according to tolerance
- Amount of liquids: residual diuresis + 500ml / day + ultrafiltered
The protein intake is higher than in a patient on hemodialysis because, during peritoneal dialysis, the losses of this nutrient are more conspicuous: in the case of peritonitis, there can also be a loss of 20g. osmolarity of glucose for blood purification and, in this way, a surplus of sugar absorption occurs. This extra calorie needs to be taken into account when drafting the diet plan.
The EBPG Nutrition Guidelines recommend the following vitamin intakes for patients on replacement therapy:
- Thiamine: 0.6-1.2mg / day
- Riboflavin: 1.1-1.3mg / day
- Pyridoxine: 10mg / day
- Ascorbic Acid: 75-90mg / day. Vitamin C deficiency is common especially in hemodialysis patients
- Folic Acid: 1mg / day
- Vitamin B12: 2.4µg / day
- Niacin: 14-16mg / day
- Biotin: 30µg / day
- Pantothenic: 5mg / day
- Vitamin A: 700-900 µg / day (supplements are not recommended)
- Vitamin E: 400-800UI (useful contribution in order to prevent cardiovascular events and muscle cramps)
- Vitamin K: 90-120 µg / day (supplements are not necessary except in patients who receive antibiotics for a long period of treatment and who have blood clotting problems)
For minerals, the Guidelines state:
- Iron: 8mg / day for men, 15mg / day for women. Additional intakes should be advised in patients who are treated with ESA (Erythropoiesis Stimulating Agent) to maintain an adequate serum level of transferrin, ferritin and hemoglobin. Oral iron supplements should be taken between meals (or at least 2 hours before or 1 hour later) to maximize the absorption of the mineral and not simultaneously with the phosphorus binders
- Zinc: 10-15mg / day for men, 8-12mg / day for women. A supplementation of 50mg / day is recommended for 3-6 months only for those patients who have overt symptoms of zinc deficiency (dermal fragility, impotence, peripheral neuropathy, altered perception of the taste and odors of food)
- Selenium: 55μg / day. Selenium supplementation is recommended in patients with deficiency symptoms: heart disease, myopathy, thyroid dysfunction, hemolysis, dermatitis.
For those suffering from chronic renal failure, there is insufficient evidence to prohibit the intake of 3-4 cups of coffee a day. Further studies are needed to investigate the benefits of this substance, especially in the elderly, children and those who have a positive family history for calcium lithiasis.
Studies on the relationship between red wine consumption and kidney disease are very limited: in patients with diabetic nephropathy on replacement therapy, moderate consumption of red wine and a diet rich in both polyphenols and antioxidants slow the progression of kidney damage. Patients with kidney disease have a high cardiovascular risk and wine, if the habit of moderate and controlled consumption is present, is a valid accessory food to be included in a meal.
For dialysis patients, who therefore have to keep your potassium intake under control, above all to be avoided: dried and oily fruit, biscuits or other types of sweets that contain chocolate, some types of fish, spices and sauces ready on the market.
Another trick consists in carrying out physical activity: it does not mean following exhausting training programs, but it is sufficient to cycle, walk or, if the physical conditions allow it, to attend swimming lessons. Athletes take potassium supplements for make up for losses due to sweating: following an active lifestyle is in fact an excellent aid in the elimination of potassium. In boiled zucchini, boiled turnips, boiled carrots, chard, chicory, aubergines, cucumbers and onions there is a low potassium content. As for fruit, you can safely consume: strawberries, apples, pears, mandarins and the syrup. Oranges, cherries, tangerines and grapes have a medium potassium content.
A diet rich in protein, such as that indicated in replacement therapy, is consequently rich in phosphorus. This mineral, contained mainly in milk and derivatives, egg yolk, meat and fish, has a recommended intake of less than 15 mg / pro g of proteins, and a diet with a low intake of these foods may involve the risk of developing a Caloric-protein malnutrition. Foods such as fish, meat, milk and derivatives cannot and must not be completely removed from the diet: the dietician's skill lies in planning a diet with a sufficient supply of protein but without excess phosphorus.
There energy distribution of meals it must have departed in five daily events: a breakfast, two snacks, one of which is mid-morning and one mid-afternoon, a lunch and a dinner. At breakfast there is a solid and a liquid food; In the middle of the morning or mid-afternoon it is essential to eat something to avoid getting too hungry for the next main meal. You can offer yogurt with cereals, or an infusion and a solid food (rusks or dry biscuits), but you can also choose a small sandwich with a slice of cheese or sliced (the quantities must be proportionate to the " daily energy). It is usual for lunch to consist of a dry first course, accompanied by a dish, a side dish and a portion of bread, all followed by fresh seasonal fruit. vegetables and, once a week, these can be replaced by meat or fish. If you like, you can add some parmesan in small quantities (generally to taste). Same composition for dinner (first course, dish, side dish, bread and fruit) : the first course is in vegetable broth (on average, the broth portion is halved compared to the dry one) and the only condiment allowed is extra-virgin olive oil, due to its important nutritional properties (avoid margarine and bur ro). It is advisable to consume at least twice a week, for lunch, a first course in which the sauce is represented by legumes or a vegetable-based soup. The portions of food must be proportionate to the patient's daily energy needs, in order to ensure the adequate intake of both macro and micronutrients. For the preparation of an adequate and pleasing diet plan, the dietician must take into account the food preferences of the chronic uremics: red meat, fish and poultry, eggs, in hemodialysis, are less welcome than peritoneal. In this way, pleasure and pleasure are combined with duty and compliance with dietary rules in order to preserve a state of health optimal possible.
Following the diet is important
Following the diet is essential for patients, regardless of the method adopted: the food plan makes dialysis treatment more effective and improves the subject's state of nutrition.
Since the uremic condition is not perfectly corrected by dialysis methods, depending on the method used to assess the state of nutrition, malnutrition in dialysis is present from 18% to 75% and is one of the factors responsible for the high mortality It can be of two types:
- Protein Energy Wasting (PEW) present from 10% to 70% with an average of 40% in chronic dialysis patients
- Excess malnutrition present in 50% of sick subjects
The major causes of malnutrition are related to the patient's severe uremic condition, to the dialysis method adopted (there may be intradialytic amino acid losses; infectious complications, such as peritonitis; blood losses, such as rupture of the filter or prolonged bleeding of the access in hemodialysis), medical therapy (taking drugs that cause nausea, vomiting or that alter the perception of taste and taste of food) and the psychological-economic sphere (uremic patients, especially if on hemodialysis, are for the most part elderly and can undergo depression, bereavement, loneliness, lack of self-sufficiency and autonomy in the preparation and procurement of the meal). These high percentages of malnutrition demonstrate how widespread the underestimation of dialysis nutrition is: the production of a dietary program and nutrition education it is hampered by a lack of interest in nutrition, economic constraints and a l high mortality rate of uremic patients. In fact, these patients have serious clinical problems that the experts in the field give priority to, allowing them to transgress widely in the diet in order to obtain a moment of gratification from it.
Bibliography
- Mario Negri Institute Milan Report [http://www.marionegri.it/mn/it/ Updating/news/archivionews12/comgan.html#.UVtBTjeICSo]
- Binetti P, Marcelli M, Baisi R. Manual of Clinical Nutrition and Applied Dietary Sciences, Universo Publishing Company, reprint 2010
- Foque D, Wennegor M, Ter Wee P, Wanner C et al., EBPG Guideline on Nutrition Nephrol Dial Transplant 22, Suppl 2; ii45-ii87
- DavideBolignano, Giuseppe Coppolino, Antonio Barilà et al., Caffeine and kidney: what evidence right now? J RenNutr 2007; 17,, 225-234.
- Presti RL., Carollo C., Caimi G. Wine consumption and renal diseases: new perspectives. Nutrition 2007 Jul-Aug; 23 (7-8): 598-602
- Renaud SC, Guéguen R, Conard P et al. Moderate wine drinkers have lower hypertension-related mortality: a prospective cohort study in French men. Am J ClinNutr 2004; 80: 621–625
- Brunori G, Pola A. Nutritional status in the dialysis patient. National Academy of Medicine: Genoa Forum service 2005
- Canciaruso, Brunori G, Kopple JD et al., Cross-sectional comparison of malnutrition in countinuous ambulatory peritoneal dialysis and haemodialysis patients. Am. J. Kidney Dis 1995; 26: 475-486
- Park YK., Kim JH., Kim KJ et al. A cross-sectional study comparing the nutritional status of peritoneal dialysis and haemodialysis patients in Korea, J. RenNutr 1999; 9: 149-156
- Panzetta G, Abaterusso C. Obesity in dialysis and reverse epidemiology: true or false?
- G ItalNefrol 2010 Nov-Dec; 27: 629-638
- Fouque D, Kalantar-Zadeh K, Kopple J, Cano N et al. A proposed nomenclature and diagnostic criteria for protein-energy wasting in acute and chronic kidney disease .Kidney International 73, 391–398
