Kidney Week

Abstract: TH-PO042

FGF23 and AKI in SPRINT

Session Information

• AKI: Epidemiology, Risk Factors, Prevention
  October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 101 AKI: Epidemiology, Risk Factors, and Prevention

Authors

• Jovanovich, Anna Jeanette, Denver VA , Denver, Colorado, United States

Anna Jeanette Jovanovich,

• Ginsberg, Charles, UCSD, San Diego, California, United States

Charles Ginsberg,

• You, Zhiying, UC Denver, Aurora, Colorado, United States

Zhiying You,

• Cheung, Alfred K., University of Utah, Salt Lake City, Utah, United States

Alfred K. Cheung,

• Chonchol, Michel, University of Colorado, Aurora, Colorado, United States

Michel Chonchol,

• Shlipak, Michael, San Francisco VA Medical Center, San Francisco, California, United States

Michael Shlipak,

• Ix, Joachim H., UCSD, San Diego, California, United States

Joachim H. Ix,

Background

Fibroblast growth factor 23 (FGF23) is elevated in chronic kidney disease and associated with kidney disease progression and increased mortality but data on FGF23 in humans with acute kidney injury (AKI) are limited. We hypothesize that high circulating intact FGF23 (iFGF23) concentrations will identify individuals at high risk of AKI and may modify the relationship between randomization to intensive blood pressure lowering and AKI in the Systolic Blood Pressure Interventional Trial (SPRINT).

Methods

The SPRINT study was a randomized multicenter trial evaluating the effects of standard (SBP <140 mmHg) vs. intensive (SBP <120 mmHg) blood pressure lowering on cardiovascular outcomes in older adults without diabetes. iFGF23 was measured in 2488 subjects with GFR < 60 mL/min/1.73m². Cox proportional hazards models adjusted for demographics, comorbidities, randomization group, and baseline number of antihypertensives, eGFR, and serum calcium and phosphorus identified the relationship between baseline iFGF23 and time to first AKI event.

Results

Mean age was 73 ± 9 years, 40% were female, and 66% were white. At baseline, mean eGFR was 49 ± 11 mL/min/1.73m² and median FGF23 was 66 [52-88] pg/mL. After full adjustment, there was no significant association between baseline iFGF23 and time to first AKI event; HR for Q4 (vs. Q1) was 0.93 (95% CI 0.60-1.44) and HR for iFGF23 modeled as a continuous variable was 0.96 (95% CI 0.75-1.23). FGF23 did not modify the relationship between randomization to intensive blood pressure lowering and AKI (p for interaction 0.12).

Conclusion

Among SPRINT participants with baseline eGFR < 60 mL/min/1.73m², there was no significant association between baseline iFGF23 and AKI events. iFGF23 did not modify the relationship between randomization to intensive blood pressure lowering and AKI.

Funding

• NIDDK Support