Abstract Body: Background: eGFR is usually calculated based on serum creatinine (eGFR_Scr) or cystatin C (eGFR_CysC). This study aimed to investigate the association between ΔeGFR_CysC-Scr and hypertension risk and to assess the mediating role of triglyceride glucose (TyG) index.
Methods: The ΔeGFR_CysC-Scr was calculated by eGFR_CysC - eGFR_Scr. A Cox proportional risk model was used to assess the association between ΔeGFR_CysC-Scr and risk of hypertension. The mediating role of TyG was assessed using mediation analysis.
Results: A total of 4,644 participants were finally included. During a mean follow-up period of 5.0 years, 613 new cases of hypertension occurred. Median (interquartile range) eGFR_Scr was 95 (89, 100) mL/min/1.73m², Median (interquartile range) eGFR_CysC was 100 (84, 109) mL/min/1.73m² (Figure 1). Multivariate analysis showed that, individuals in negative-ΔeGFR_CysC-Scr group (<-15) had a 24.4% increased risk of hypertension (Hazard ratio [HR]=1.244; 95% confidence interval [95% CI]: 0.993, 1.557), while positive-ΔeGFR_CysC-Scr group (≥15) had a 19.9% decrease risk of hypertension (HR=0.801; 95% CI: 0.630, 1.019). In the segmented analysis, the association between ΔeGFR_CysC-Scr and hypertension risk was stronger below the cut-off value. For ΔeGFR_CysC-Scr <3.83 mL/min/1.73m², each standard deviation decrease was associated with a 12% lower risk (HR=0.88, 95% CI: 0.79, 0.98, P=0.015), while for ΔeGFR_CysC-Scr ≥3.83 mL/min/1.73m², the risk corresponding to each standard deviation increase was almost constant (HR=0.97; 95% CI: 0.86, 1.09; P=0.610) (Figure 2). In addition, each 15 mL/min/1.73m² increase in ΔeGFR_CysC-Scr was associated with a 13.4% reduction in the risk of hypertension (HR= 0.866; 95% CI: 0.794, 0.945). TyG acted as a partial mediator, explaining 9.3% of the total effect.
Conclusion: The present study demonstrates an association between ΔeGFR_CysC-Scr and the risk hypertension and reveals the important mediating role of TyG in this association.