Effect of Dietary Interventions on Phase Angle in Patients with Chronic Kidney Disease Undergoing Dialysis: A...

Phase angle (PhA), derived from bioelectrical impedance analysis, is inversely associated with malnutrition, a common condition in chronic kidney disease (CKD) managed through dietary therapy. Although evidence from oncology and sports medicine suggests nutritional interventions may improve PhA, supporting its potential use as a marker of therapeutic efficacy, data from CKD remain limited.

The impact of nutritional-related interventions on PhA values in patients with CKD and undergoing dialysis was evaluated in this systematic review and meta-analysis.

A systematic literature search for clinical trial studies was conducted in the PubMed, Scopus, Web of Science, CINAHL, and Embase databases up to September 2025.

Eligible clinical trials included adults with CKD and undergoing dialysis, applying any dietetic intervention as compared with a control, and reporting PhA variations. Meta-analysis was conducted only on data from randomized clinical trials (RCTs) and analyzed by stratification according to intervention details.

A total of 14 studies (n = 9 RCTs) comprising 969 participants were included in the review. Overall, there was no influence of dietetic intervention accompanied or not by an exercise-related component, compared with standard of care (ie, no intervention), on PhA values (mean difference [MD] = 0.22; 95% CI, -0.20 to 0.63; P < .001; I2 = 78%), nor did the isolated effect of the dietary component (MD = 0.26; 95% CI, -0.22 to 0.73; P < .001; I2 = 80%) or use of amino acids or a protein-based unimodal intervention (MD = 0.49; 95% CI, -0.19 to 1.17; P < .001; I2 = 73%) have an impact.

Our meta-analysis did not show influences of dietetic intervention on PhA among patients with CKD who are undergoing dialysis. However, given low number of RCTs and important risk of bias, high-quality RCTs are needed to verify our findings.

PROSPERO no. CRD42024601056.