Renal hyperfiltration dynamics as a cardiovascular risk stratification marker

Renal hyperfiltration (RHF) is a precursor to adverse clinical outcomes. However, RHF is a dynamic condition that can develop or disappear over time, and the prognostic implications of this transition remain unclear. This nationwide cohort study included 1,022,062 individuals of Korean ethnicity who underwent consecutive health screening examinations between 2012 and 2015. RHF was defined as an estimated glomerular filtration rate (eGFR) exceeding the 95th percentile after multiple adjustments. The participants were categorized based on their RHF transitions (RHF-free, developed, disappeared, and persistent), and risks of mortality and cardiovascular (CV) events were assessed. Compared with RHF-free individuals, those with persistent RHF had the highest risks of mortality (adjusted hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.24–2.10) and CV events (1.39, 1.13–1.71). Mortality risk increased across all other transition patterns regardless of exposure duration or the slope of hyperfiltration excess. Conversely, CV risk increased primarily in the RHF-disappeared, particularly with longer RHF exposure and declining hyperfiltration excess, but not with RHF-development. RHF dynamics showed distinct outcome-specific associations. Compared with the RHF-free pattern, mortality increased across all other RHF transition patterns, whereas CV events increased only in the RHF-disappeared and RHF-persistent patterns.