Kidney Week

Abstract: FR-PO290

Plasma Renin Activity in CKD: A Descriptive and Prognostic Analysis

Session Information

• CKD: Epidemiology and Risk Factors
  November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Mehdi, Ali, Cleveland Clinic Foundation, Cleveland, Ohio, United States

Ali Mehdi,

• Nakhoul, Georges, Cleveland Clinic Foundation, Cleveland, Ohio, United States

Georges Nakhoul,

• Arrigain, Susana, Cleveland Clinic Foundation, Cleveland, Ohio, United States

Susana Arrigain,

• Schold, Jesse D., Cleveland Clinic Foundation, Cleveland, Ohio, United States

Jesse D. Schold,

• Taliercio, Jonathan J., Cleveland Clinic Foundation, Cleveland, Ohio, United States

Jonathan J. Taliercio,

Background

Elevated plasma renin activity (PRA) is associated with poor clinical outcomes including death and cardiovascular events. There is conflicting studies regarding associations of PRA with incident CKD, CKD stages, and renal prognosis.

Methods

We evaluated patients included in the Cleveland Clinic CKD registry with documented PRA values from 2005-2017. Patients with primary hyperaldosteronism or renal artery stenosis were excluded. PRA values were stratified into quartiles and adjusted Cox models were utilized to evaluate survival. Adjusted mixed models were used to test the interaction between PRA and slope of eGFR over time.

Results

Among 1124 patients analyzed, PRA correlated inversely with eGFR (1.9 vs 1.2ug/L/hr for eGFR 15-29 vs 60-89 mL/min/ 1.73 m²; p<0.001). Table 1 shows the patient characteristics by PRA quartiles. Patients in Q1 were older, more African American, had lower BMI, and more were on beta blocker therapy. They had higher systolic and diastolic blood pressures and were more likely to require 3+ blood pressure medications. All these associations were statistically significant (table 1). With median follow-up of 3.2 years, mortality was not different across PRA quartiles on adjusted Cox model analysis (P=0.16). On mixed model analysis, a significant association was noted between log PRA and time (slope of monthly eGFR decline = 0.02; p=0.014) suggesting a protective effect of higher PRA levels. In stratified analyses, this association was significant with baseline eGFR >50mL/min/ 1.73 m² but not lower eGFR.

Conclusion

While the mechanism remains unclear, PRA appears to correlate inversely with eGFR. Findings suggest a protective effect of higher PRA against CKD progression when eGFR is above 50 mL/min/1.73 m². Congruent with prior studies, lower PRA values are evident in older age, African Americans, and Beta Blocker therapy. Our study also suggests that lower PRA is associated with a more resistant hypertension. Whether this represents high salt intake or undiagnosed autonomous hyperaldosteronism is unclear.