Table 3.
A schematic revision of limits and advantages of interventions to improve the nutritional status of dialysis patients.
| The Field of Intervention | Intervention | Pros | Cons |
|---|---|---|---|
| Dialysis optimization | Increasing efficiency and tolerance by increasing frequency (daily or more frequent dialysis) [200,201,202,203,204,205,206,207,208,209,210,211,212,213] | Improvement in nutritional status in most of prospective studies (see also pregnancy on dialysis) | May be difficult to organize; possibly higher risk of vascular access problems |
| Increasing efficiency and probably also tolerance by switching to convective dialysis modalities (such as high flow haemodiafiltration) [214,215,216,217,218,219,220,221,222,223,224,225,226] | Efficiency is associated with nutritional status at least in “standard patients” | Losses may be significant in elderly, malnourished patients. No demonstration of nutritional advantages | |
| Decreasing losses, and preserving renal function (incremental dialysis, tailored dialysis) [227,228,229,230,231,232,233,234,235,236,237,238,239,240,241,242] | Residual diuresis and residual renal function are two of the most powerful predictors of survival; “dialysis shock” may be a cause of early death after dialysis start | Experience is still limited and there is still no agreed standard | |
| Physical exercise | Physical exercise is theoretically a powerful means of improving clinical conditions and nutritional status in patients with a chronic disease [243,244,245,246,247,248,249,250,251,252] | The best results have been reported in observational studies; biases linked to self-selection limit the generalization of results. | Barriers are evident in the elderly population, in which inactivity is often the result of the same comprehensive physical failure that causes malnutrition |
| Metabolic interventions * | Anemia correction [253,254] | ESA improved quality of life, fertility and sex life, issues associated with nutritional status | The association between lack of response to ESAs, inflammation, malnutrition and atherosclerosis is part of the MIA syndrome |
| Thyroid hormones [255] | The euthyroid sick syndrome or “low T3 syndrome” is typical of malnutrition/starvation | Correction of the metabolic deficit can worsen the clinical picture | |
| Androgen steroids [256,257,258,259] | Recently reconsidered therapeutic options include nandrolone decanoate and oxymetholone, which display good effects on sarcopenia | Side effects may be relevant; this treatment could be considered in males with testicular failure and severe sarcopenia | |
| Recombinant growth hormone [260,261,262,263,264,265,266,267] | Recombinant growth hormone is routinely used in children on dialysis. In adults, growth hormone is often low, and the effect on severe malnutrition has been favorable | High costs and side effects limit its use | |
| Nutritional interventions | Increasing the quantity/quality of food [268,269,270,271,272,273,274,275,276,277,278] | The best tool for improving nutritional status, eating during dialysis may be an important way to improve the nutritional status of dialysis patients | If malnutrition is linked to inflammation and atherosclerosis, it is difficult to increase the quantity or quality of food |
| Nutritional supplements (oral) [279,280,281,282,283,284,285,286,287,288,289,290,291,292] | Can be of use especially for limited periods of time; specific supplements for dialysis patients (poor in phosphate) are also available | Can decrease appetite for “normal” food; may be less tasty after a longer period | |
| Intravenous or enteral supplements [293,294,295] | Can help reverse acute malnutrition, especially in the case of failure of the two previous interventions | May further reduce food intake; and create a need for a high quantity of fluids; metabolic derangements are frequent in the long term |
* All major metabolic derangements, including acidosis, hyperparathyroidism and hypovitaminosis D, are associated with poor nutritional status and higher mortality in dialysis.