Discordance between Cystatin C-based and Creatinine-based estimated glomerular filtration rate and health outcomes in adults: a systematic review and meta-analysis
Qiaoling Liu, Paul Welsh, Carlos Celis-Morales, Frederick K Ho, Jennifer S Lees, Patrick B MarkAbstract
Background
The intra-individual difference in Cystatin C-based and Creatinine-based estimated glomerular filtration rate (eGFRcys, eGFRcr, respectively), i.e., eGFR discordance, has recently been demonstrated to have prognostic implications. It was associated with mortality, cardiovascular, and renal outcomes. We presented a systematic review and meta-analysis to summarize existing literature.
Methods
We searched PubMed, Embase, and MEDLINE up to April 28, 2024 for cohort and cross-sectional studies in English reporting the association of eGFR discordance with mortality, cardiovascular, and renal outcomes. The quality of studies was evaluated by Risk Of Bias In Non-randomized Studies - of Exposure form. Data from studies were extracted to a pre-defined table and pooled using a random-effects model. Stratified and sensitivity analyses were performed.
Results
A total of 1489 studies were initially identified, of which 18 studies with longitudinal or cross-sectional designs were included, with a sample size between 373 and 363494 people. The risk of bias was generally low to some concerns. eGFR was mainly calculated using Chronic Kidney Disease Epidemiology Collaboration equations, while a few studies applied other equations. An eGFR discordance featuring lower eGFRcys, e.g., eGFRcys≤60% of eGFRcr, or eGFRcys - eGFRcr≤ -15 ml/min/1.73m2 was consistently associated with higher mortality and elevated risk of cardiovascular and renal outcomes. People with lower eGFRcys have a 58% greater risk of mortality (HR=1.58, 95%CI: 1.42, 1.76), and 32% greater risk of cardiovascular events (HR=1.32, 95%CI: 1.25, 1.39. People with higher eGFRcys have a 39% lower risk of mortality (HR=0.61, 95%CI: 0.52, 0.70), and 29% lower risk of cardiovascular events (HR=0.71, 95%CI: 0.62, 0.81). No meta-analysis for renal outcomes was conducted due to data availability.
Conclusions
The eGFR discordance serves as a meaningful indicator of adverse health outcomes. The lack of a consensus on the cut-off value of eGFR discordance and the mixture use of eGFR equations warrants attention.