Kidney Week

Abstract: PO1975

The Optimal Equation of Estimated Glomerular Filtration Rates for Pediatric CKD Patients in Transition from Adolescent to Adult: Results from KNOW-PedCKD

Session Information

• Pediatric Nephrology: AKI, Dialysis, Transplant, CKD, and Nephrotic Syndrome
  November 04, 2021 | Location: On-Demand, Virtual Only
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

• 1700 Pediatric Nephrology

Authors

• Lim, Seon Hee, Uijeongbu Eulji Medical Center, Uijeongbu-si, Gyeonggi-do, Korea (the Republic of)

Seon Hee Lim, MD

• Park, Eujin, Hallym University Medical Center, Yeongdeongpo-gu, Seoul, Korea (the Republic of)

Eujin Park,

• Han, Kyoung Hee, Jeju University Hospital, Jeju, Korea (the Republic of)

Kyoung Hee Han,

• Kim, Seong heon, Pusan National University Hospital, Busan, Korea (the Republic of)

Seong heon Kim,

• Cho, Heeyeon, Samsung Medical Center, Gangnam-gu, Seoul, Korea (the Republic of)

Heeyeon Cho,

• Shin, Jae Il, Severance Hospital, Seodaemun-gu, Seoul, Korea (the Republic of)

Jae Il Shin,

• Cho, Min Hyun, Kyungpook National University School of Medicine, Daegu, Daegu, Korea (the Republic of)

Min Hyun Cho,

• Lee, Joo Hoon, Asan Medical Center, Songpa-gu, Seoul, Korea (the Republic of)

Joo Hoon Lee,

• Ha, Il-Soo, Seoul National University College of Medicine Department of Pediatrics, Jongno-gu, Korea (the Republic of)

Il-Soo Ha,

• Kang, Hee Gyung, Seoul National University College of Medicine Department of Pediatrics, Jongno-gu, Korea (the Republic of)

Hee Gyung Kang,

• Park, Peong Gang, Ministry of Health and Welfare, Sejong, Korea (the Republic of)

Peong Gang Park,

• Ahn, Yo Han, Seoul National University College of Medicine Department of Pediatrics, Jongno-gu, Korea (the Republic of)

Yo Han Ahn,

Background

Estimated glomerular filtration rate (eGFR) is an important value in kidney function evaluation, and it is useful to identify chronic kidney disease (CKD) and its progression. Clinicians use various equations to calculate eGFR which is based on serum creatinine (Cr) or cystatin C (CysC) concentration with other variables such as age, sex, and height. However, there is a lack of consensus on which equation is proper for patients in transition from adolescent to adult. Therefore, we evaluated the reliability of various eGFR calculation methods compared to measured isotope GFR (iGFR) in adolescents and young adults with CKD.

Methods

Seventy-three patients aged from 15 to 23 years were included in the KoreaN cohort study for Outcome in patients With Pediatric Chronic Kidney Disease (KNOW-PedCKD). We compared measured iGFRs with various eGFR calculation equations; the bedside serum Cr based equation (Schwartz_Cr), the CysC based equation (Schwartz_CysC), combined Cr and CysC-based Chronic Kidney Disease in Children equation (CKiD_Cr-CysC), the Cr-only CKD-EPI (CKD-EPI_Cr), and combined Cr and CysC CKD-EPI equation (CKD-EPI_Cr-CysC).

Results

Fifty-two (71.2%) patients were male and 86.3% of patients had non-glomerular causes of CKD. A total of 136 measurements of iGFR was performed at the median age of 17.0 (interquartile range (IQR) 16.0–18.8) years. The mean iGFR was 42.2 ± 29.0 mL/min/1.73m². The Schwartz_Cr equation had lowest bias (-0.6 mL/min/1.73m²), high correlation (0.96), and highest accuracy (81.6% within 30% of iGFR) while Schwartz_CysC, CKiD_Cr-CysC, CKD-EPI_Cr, and CKD-EPI_Cr-CysC had an overestimation bias (+1.4, +2.1, +15.5 and +8.9 mL/min/1.73m², respectively). In adolescents (n=93) from 15 to 18-year-old, the bias of Schwartz_Cr equation was lowest (+0.3 mL/min/1.73m²) and its accuracy was highest (81.7% within 30% of iGFR). In young adults (n=43) older than 18-year-old, the bias of the CKiD_Cr-CysC equation was lowest (+1.3 mL/min/1.73m²) and the accuracy of Schwartz_Cr was highest (81.4% within 30% of iGFR).

Conclusion

The Schwartz_Cr equation may be an optimal method to calculate eGFR in adolescents and young adults with CKD.