Abstract: SA-PO409

Comparison of eGFR with Creatinine and Cystatin C by eCKD-EPI in CKD Patients with and without Hypoalbuminemia

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 302 CKD: Estimating Equations, Incidence, Prevalence, Special Populations

Authors

  • Varela, Carlos Federico, Hospital Italiano de Buenos Aires, CABA, Argentina
  • Jimenez, Graciela, Hospital Italiano de Buenos Aires, CABA, Argentina
  • Bratti, Griselda, Hospital Italiano de Buenos Aires, CABA, Argentina
  • Ocampo, Maria Lorena, Hospital Italiano Buenos Aires, CABA, Argentina
  • Greloni, Gustavo, Hospital Italiano de Buenos Aires, CABA, Argentina
  • Rosa Diez, Guillermo, Hospital Italiano de Buenos Aires, CABA, Argentina
Background

Serum cystatine C (CysC) could be a better predictor than serum creatinine (Crea) in comorbid patients with CKD. Differences between CysC and Crea eGFR in patients with and without hypoalbuminemia (hypoA) were poorly understood/studied. We compare average differences between eGFR based on CysC and Crea in patients with and without hypoalbuminemia.

Methods

We estimated GFR by the new CKD-EPI equations based on CysC and Crea
The CKD stage was determined by the Crea-based eGFR.
HypoA was defining by serum albumin ≤ 3.5 gr/L.
In each CKD stage, differences between average of CysC and Crea-based equation and concordance to assign to the same CKD stage were calculated.
We performed the same analysis in patients with and without hypoA.

Results

We included 1954 patients, (46.5% female) aging 63±18 years. 50.9% were elderly. Mean Crea, CysC and serum albumin in total group were 1.6 ± 1.2 mg/dl, 2.1±1.1 mg/dl and 3.5±0.6 gr/L respectively. Mean of eGFR of Crea was 54.8± 28 and CysC was 38.9±25 ml/min/1.73.Mean differences between eGFR of Crea and CysC were 34.9, 21.5, 14.2, 10.1, 5.5, -0.9 ml/min/1.73 for stage 1 to 5 respectively in total group.
Serum albumin was 2.8±0.4 and 3.9±0.3 gr/L in patients with and without hypoA. Patients with hypoA had significantly differences between mean eGFR of Crea and CysC compared with those without hypoA, showing 48 vs 17 in stage1, 31 vs 15 in stage 2, 19 vs 11 in stage 3A, 13 vs 8 in stage 3B, 6 vs 4 in stage 4 and -0.9 vs -0.8 in stage 5. All differences except stage 5 were significant.

Conclusion

Differences between eGFR in CysC and Crea-based equation could be affected in the setting of low serum albumin values. Patients with hypoA show highest differences.

Table: 1. Characteristics of the study population.
CKD stage123A3B45
Serum Creatinine0.72
(0.17)
0.96
(0.20)
1.26
(0.21)
1.66
(0.33)
2.62
(0.66)
5.46
(1.73)
Serum Cystatine C1.23
(0.46)
1.45
(0.48)
1.82
(0.61)
2.29
(0.72)
3.29
(0.95)
4.48
(1.01)
CKD-EPI-Crea105.2
(14.1)
73.1
(8.8)
51.8
(4.3)
37.5
(4.2)
22.5
(4.5)
10.1
(2.8)
CKD-EPI-CysC70.3
(28.8)
51.6
(21.3)
37.6
(14.8)
27.4
(10.7)
16.9
(6.1)
11.1
(3.5)
       
Concordance Crea vs CysC38.8 %46.7 %68.9 %80.1 %49.1 %44.8 %
Diff hypoalbuminemia48 (±23)31 (±16)19 (±12)13 (1±0)6 (±6)-0.9 (±3)
Diff without hypoalbuminemia17 (±23) °°15 (±20) °°11 (±14) °°8 (±9) °°4 (±5) °-0.8 (±3)

References: . °°; p value < 0.001 and °; p value < 0.05 between patients with and without hypoA.