Table 2.
Simulated vs reported glomerular filtration rate (GFR) values for children aged 8–9 years with and without obesity
| Estimation methodsa | Nonobese | Obese | Obese/nonobese (%) | |||
|---|---|---|---|---|---|---|
| Reported [35] | Simulated | Reported [35] | Simulated | Reported [35] | Simulated | |
| Absolute (mL/min) | 65.0 (21.7) | 73.3 (24.7) | 112.8 | |||
| CrCl | 93.2 (21.0) | 120.8 (21.5) | 129.1 | |||
| GFR, Zappitelli | 79.8 (10.5) | 100.1 (14.4) | 125.4 | |||
| GFR, Schwartz | 65.1 (8.3) | 83.2 (12.5) | 127.8 | |||
| Weight-adjusted (mL/min/kg) | 1.92 (0.68) | 1.64 (0.59) | 85.4 | |||
| CrCl | 3.4 (0.7) | 2.8 (0.5) | 82.4 | |||
| GFR, Zappitelli | 2.9 (0.4) | 2.3 (0.2) | 79.3 | |||
| GFR, Schwartz | 2.4 (0.3) | 1.9 (0.2) | 79.2 | |||
| BMI-adjusted (mL/min/kg/m2) | 3.54 (1.32) | 3.03 (1.07) | 85.6 | |||
| CrCl | 5.8 (1.4) | 5.2 (1.0) | 89.7 | |||
| GFR, Zappitelli | 5.0 (0.7) | 4.3 (0.5) | 86.0 | |||
| GFR, Schwartz | 4.1 (0.5) | 3.6 (0.4) | 87.8 | |||
| LBM-adjusted (mL/min/kg) | 2.33 (0.78) | 2.20 (0.77) | 94.4 | |||
| CrCl | 3.9 (0.8) | 3.7 (0.6) | 94.9 | |||
| GFR, Zappitelli | 3.4 (0.4) | 3.0 (0.3) | 88.2 | |||
| GFR, Schwartz | 2.7 (0.3) | 2.5 (0.2) | 92.6 | |||
| FFM-adjusted (mL/min/kg) | 2.56 (0.85) | 2.44 (0.85) | 95.3 | |||
| CrCl | 4.6 (1.0) | 5.0 (0.9) | 108.7 | |||
| GFR, Zappitelli | 3.9 (0.6) | 4.1 (0.6) | 105.1 | |||
| GFR, Schwartz | 3.2 (0.5) | 3.4 (0.5) | 106.3 | |||
| BSA-adjusted (mL/min/1.73 m2) | 99.2 (32.8) | 96.5 (33.0) | 97.3 | |||
| CrCl | 162.0 (34.4) | 160.7 (26.3) | 99.2 | |||
| GFR, Zappitelli | 138.5 (15.7) | 132.1 (13.0) | 95.4 | |||
| GFR, Schwartz | 112.7 (11.2) | 109.6 (10.4) | 97.2 | |||
Values reported as mean (standard deviation). The ratio of obese/nonobese was calculated using mean data
BMI body mass index, BSA body surface area, CrCl creatinine clearance, FFM fat-free mass, LBW lean body weight
aThe three reported GFR estimation methods include (1) estimating CrCl through a 24-h urine collection as a surrogate measure of GFR, (2) estimation of GFR using the Zappitelli equation, and (3) estimation of GFR using the Schwartz equation [48, 49]. Simulated GFR is estimated based on each virtual subject’s kidney size. Further description and equations for each method are provided in Sect. 1.4 of the ESM