Kidney Week

Abstract: TH-PO017

Admission Calcium-Phosphate Product Levels and Risk of AKI in Hospitalized Patients

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

• Mao, Michael A., Mayo Clinic, Rochester, Minnesota, United States

Michael A. Mao,

• Cheungpasitporn, Wisit, University of Mississippi Medical Center, Jackson, Mississippi, United States

Wisit Cheungpasitporn,

• Thongprayoon, Charat, Bassett Medical Center, Cooperstown, New York, United States

Charat Thongprayoon,

• Erickson, Stephen B., Mayo Clinic, Rochester, Minnesota, United States

Stephen B. Erickson,

Background

An increased serum calcium-phosphate product (CaP) can result in acute kidney injury (AKI) due to tubular and interstitial calcium phosphate deposits. In addition, CaP of >55 mg²/dL² is associated with systemic calcification. However, the risk of AKI development among hospitalized patients with different calcium-phosphate product levels on admission remains unclear.

Methods

All adult hospitalized patients who had both admission serum calcium and phosphate levels available between years 2009 and 2013 were enrolled. Admission CaP was categorized based on its distribution into six groups (<22, 22-<27, 27-<32, 32-<37, 37-<42 and ≥42 mg²/dL²). The odds ratio (OR) of in-hospital mortality by admission CaP, using the CaP category of <22 mg²/dL² as the reference group, was obtained by logistic regression analysis.

Results

After excluding patients with end stage renal disease (ESRD), without serum creatinine measurement, and those with AKI at presentation, a total of 9,864 patients were studied. In-hospital AKI occurred in 1,478 (15.0%) patients. The incidence of AKI among patients with admission CaP <22, 22-<27, 27-<32, 32-<37, 37-<42 and ≥42 mg²/dL² was 11.1%, 12.4%, 14.9%, 15.2%, 17.5%, and 19.9%, respectively. After adjusting for potential confounders, CaP >37 mg²/dL² was associated with an increased risk of developing AKI, with ORs of 1.53 (95% CI 1.19-1.96) and 1.63 (95% CI 1.25-2.14) in patients with admission CaP 37-<42 and ≥42, respectively. Among a subgroup of patients with available serum albumin, after adjusting for potential confounders, corrected CaP >27 mg²/dL² was associated with an increased risk of developing AKI with ORs of 1.50 (95% CI 1.06-2.15), 1.49 (95% CI 1.06-2.13), 1.85 (95% CI 1.30-2.67) and 1.69 (95% CI 1.16-2.49) when CaP were within 27-<32, 32-<37, 37-<42 and ≥42 mg²/dL², respectively.

Conclusion

Elevated admission CaP was associated with an increased risk for in-hospital AKI.