Kidney Volume and Risk of Incident Kidney Outcomes

Area of Science:

• Nephrology
• Biomarkers
• Genetics

Background:

• Low total kidney volume (TKV) is a known risk factor for chronic kidney disease (CKD).
• Existing research lacks comprehensive analysis of nonlinear associations, incident events, causal inference, and prognostic utility of TKV beyond established biomarkers.

Purpose of the Study:

• To investigate the association between TKV and incident chronic kidney disease (CKD), acute kidney injury (AKI), and cardiovascular events.
• To evaluate the prognostic utility of TKV in CKD risk stratification.
• To explore the bidirectional relationship between genetically predicted TKV and kidney/cardiovascular traits using Mendelian randomization.

Main Methods:

• Derived TKV, height-adjusted TKV, and BSA-TKV from 34,595 UK Biobank participants.
• Employed Cox proportional hazard models to assess associations with incident CKD, AKI, and cardiovascular events.
• Utilized Mendelian randomization to examine causal relationships between TKV and kidney/cardiovascular traits.

Main Results:

• Lower TKV (10 mL) correlated with a 6% increased risk of incident CKD, independent of eGFR and albuminuria.
• TKV did not show association with incident AKI or cardiovascular events.
• BSA-TKV and prognostic thresholds improved CKD risk prediction accuracy.
• Mendelian randomization revealed a bidirectional link between genetically predicted TKV and CKD risk.

Conclusions:

• Kidney volume is an independent predictor of incident CKD, beyond traditional risk factors.
• A bidirectional causal relationship exists between kidney volume and CKD.
• TKV holds prognostic value for CKD risk stratification.