Demographic data and performance of GFR estimation equations
| All subjects | Group 1 | Group 2 | Group 3 | |
|---|---|---|---|---|
| n | 293 | 99 | 97 | 97 |
| Mean weight (kg) | 91.9 | 74.3 | 91.2 | 110.5 |
| Male/female | 221/72 | 61/38 | 71/21 | 84/13 |
| Age (years) | 55.2 ± 9.4 (55.0 [49.0–62.8]) | 57.3 ± 9.9 (60.0 [50.8–65.0]) | 56.3 ± 8.6 (57.0 [50.0–63.0]) | 51.9 ± 8.9 (51.0 [46.5–58.0]) |
| Weight (kg) | 91.9 ± 17.0 (91.5 [80.3–102.5]) | 74.3 ± 7.8 (75.8 [69.9–80.4]) | 91.2 ± 4.1 (91.5 [87.3–94.8]) | 110.5 ± 11.6 (106.9 [102.5–114.3]) |
| A1C (%) | 7.79 ± 2.00 (7.2 [6.3–9.1]) | 7.87 ± 2.18 (7.2 [6.2–9.3]) | 7.69 ± 1.74 (7.4 [6.4–9.1]) | 7.81 ± 2.06 (7.0 [6.5–9.0]) |
| Fasting plasma glucose(mmol/l) | 9.67 ± 3.04 (8.7 [7.4–11.4]) | 9.69 ± 3.29 (8.6 [7.3–11.7]) | 9.48 ± 2.75 (8.9 [7.1–11.4]) | 9.83 ± 3.07 (9.0 [7.7–11.2]) |
| Creatinine (μmol/l) | 80.0 ± 14.8 (80.0 [69.3–90.0]) | 76.8 ± 14.3 (76.0 [66.8–86.3]) | 81.1 ± 15.3 (80.0 [70.0–89.0]) | 82.0 ± 14.3 (83.0 [71.5–92.5]) |
| AER (mg/day) | 10.9 ± 34.7 | 7.2 ± 15.2 | 9.6 ± 22.4 | 16.1 ± 42.8 |
| iGFR | 114.9 ± 22.4 (111.0 [98.0–130.0]) | 110.8 ± 20.4 (107.0 [96.0–125.0]) | 113.8 ± 21.8 (109.0 [98.0–130.50]) | 120.1 ± 24.0 (116.0 [102.0–138.5]) |
| CG | MDRD | CG | MDRD | CG | MDRD | CG | MDRD | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| eGFR | 101.2 ± 26.8 | 89.9 ± 19.0 | 90.2 ± 20.5 | 89.5 ± 17.6 | 99.1 ± 24.3 | 89.0 ± 19.9 | 114.5 ± 29.4 | 91.2 ± 19.5 | ||||
| Bias (95% CI) | −13.7 (−16.0 to −11.4) | −25.0 (−26.9 to −23.1) | −20.6 (−23.9 to −17.3) | −21.3 (−24.6 to −18.0) | −14.7 (−18.5 to −10.9) | −24.8 (−28.1 to −21.5) | −5.6 (−9.8 to −1.4) | −28.9 (−32.1 to −25.7) | ||||
| Precision (95% LOA) | 19.7 (−52.3 to 24.9) | 16.6 (−57.5 to 7.6) | 16.3 (−52.6 to 11.4) | 16.6 (−53.7 to 11.2) | 18.9 (−51.8 to 22.3) | 16.5 (−57.1 to 7.5) | 20.9 (−46.6 to 35.3) | 16.0 (−60.3 to 2.5) | ||||
| 10% accuracy | 30 (24–35) | 15 (11–19) | 20 (12–28) | 20 (12–28) | 30 (21–39) | 14 (7–22) | 39 (29–49) | 10 (4–16) | ||||
| 30% accuracy | 86 (82–90) | 79 (74–84) | 80 (72–88) | 88 (81–94) | 84 (76–91) | 74 (65–83) | 94 (89–99) | 74 (65–83) | ||||
| r2 | 0.481 | 0.475 | 0.465 | 0.396 | 0.443 | 0.478 | 0.505 | 0.558 | ||||
Data are means ± SD, median [interquartile range], or percent (95% CI) unless otherwise indicated. All r2 values were positive and statistically significantly different from zero. Bias is calculated as the mean difference between eGFR and measured (isotopic GFR [iGFR]) values. Precision is the SD of the bias (95% limits of agreement [LOA]) of eGFR and isotopic GFR. Accuracy reflects the proportion of eGFR values within 10% and 30% of isotopic GFR. r2 values of eGFR vs. isotopic GFR are shown. AER, albumin excretion rate; CG, Cockcroft-Gault.