Sarcopenia and Its Individual Traits Independently Predict Mortality in Patients on Dialysis: A Systematic Review and Meta-Analysis

Background

Loss of muscle mass, muscle weakness and the combination of the two are commonly observed in patients on dialysis and may have a negative impact on their survival. In this systematic review and meta-analysis (MA), we evaluated the consistency and strength of the association between mortality risk and the presence of low muscle mass with adequate muscle strength, low muscle strength with adequate muscle mass and sarcopenia (low muscle mass and strength combined) in patients on dialysis. Ultimately, we aimed to grade which of these three conditions had the strongest association with increased mortality risk in this vulnerable group of patients.

Methods

We searched for studies published until 31 January 2024 that evaluated sarcopenia and its individual components in patients aged > 18 years on dialysis (haemodialysis and peritoneal dialysis) and that had a mean follow-up for mortality for ≥ 12 months. Included studies had to enable the evaluation of sarcopenia traits to identify patients with low muscle mass and adequate muscle strength, low muscle strength with adequate muscle mass, and sarcopenia. A systematic search was conducted in MEDLINE (by PubMed), Embase, Web of Science, Lilacs and grey literature (i.e., Google Scholar and ProQuest). We estimated consistency in the association between sarcopenia traits and death using random effects MA and reporting hazard ratio (HR) with a 95% confidence interval (95% CI).

Results

The electronic search retrieved 5712 records. After removing duplicated records and those that did not meet the eligibility criteria, 19 studies were included in the qualitative synthesis (4281 participants) and 17 studies (4024 participants) with extractable data for the MA. The MA showed low heterogeneity in the association between muscle parameters and sarcopenia with the risk of death: low muscle mass with adequate muscle strength, HR: 1.49; 95% CI: 1.04 to 2.13; I² = 0%; low muscle strength with adequate muscle mass, HR: 1.82; 95% CI: 1.38 to 2.41; I² = 0%; and sarcopenia, HR: 2.02; 95% CI: 1.61 to 2.54; I² = 40%.

Conclusion

Although being statistically significant, the association between low muscle mass and mortality seems to be less strong than the association between low muscle strength and mortality in patients on dialysis. Those presenting with a combination of the two traits, that is, sarcopenia, showed the highest risk of dying prematurely.