Malnutrition, specifically protein-energy wasting (PEW), is common in patients with chronic kidney disease (CKD), and its prevalence increases as CKD progresses. Oral nutritional supplementation (ONS) with complete formulas specific to this pathology, is a strategy aimed at meeting energy and protein requirements that are not possible with dietary recommendations and advice alone. This study systematically reviewed the available scientific literature on the safety and effectiveness of nutritional therapy with complete formulas specially designed for adults with CKD who have PEW that is not reversible through ordinary food consumption.

We systematically searched for articles published up to May 2018 in several electronic databases. We included comparative studies that evaluated the safety and effectiveness of complete nutritional formulas for malnourished adults with CKD. Relevant outcomes included rates of death, hospitalization, and adverse effects, and changes in nutritional status, anthropometrics, and health-related quality of life (HRQoL).

Three systematic reviews and 22 primary studies were identified. The primary studies comprised nine randomized controlled trials, nine non-randomized comparative studies, and four before-after studies (the latter were only included in the safety review). The majority of studies were conducted in patients on hemodialysis. The studies exhibited methodological heterogeneity in terms of the methods used to measure nutritional status and the interventions and comparators evaluated. There was also inconsistency among the results. Adherence to ONS, especially in the long term, can be affected by taste fatigue produced by repeatedly taking the same formula. Some studies recommend supplementation during hemodialysis sessions.

The studies with less risk of bias indicated a trend toward improvements in rates of death and hospitalization, HRQoL and, to a lesser extent, some anthropometric variables and serum markers, such as albumin, when ONS was given to patients with CKD. High quality comparative studies are needed to make conclusive statements about the effectiveness of this intervention.