How Reliable Is Estimation of Glomerular Filtration Rate at Diagnosis of Type 2 Diabetes?

Pathophysiology/Complications

Address correspondence and reprint requests to Richard A. Chudleigh, Llandough Hospital, Diabetes Research Unit, Penlan Road Penarth, Cardiff CF64 2XX. E-mail: rachudleigh{at}hotmail.com

Diabetes Care 2007 Feb; 30(2): 300-305. https://doi.org/10.2337/dc06-1688

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Figure 1—
Relation of CG- and MDRD-calculated eGFR with ⁵¹Cr-EDTA–measured iGFR. The solid line represents the regression line, and the dotted lines represent 95% prediction intervals for iGFR based on eGFR.

Table 1—

Demographic data

	All subjects	Group 1 (iGFR <90)	Group 2 (iGFR ≥90)
n	292	37	255
Men/women	219/73	25/12	194/61
Age (years)	55.3 ± 9.4	62.8 ± 6.4	54.2 ± 9.3*
Weight (kg)	92.0 ± 17	88.0 ± 16.7	92.5 ± 17.0
BMI (kg/m²)	31.5 ± 5.6	30.9 ± 6.0	31.6 ± 5.5
A1C (%)	7.79 ± 2.00	7.16 ± 1.83	7.88 ± 2.01*
Fasting plasma glucose (mmol/l)	9.70 ± 3.09	8.44 ± 2.49	9.87 ± 3.13*
Creatinine (μmol/l)	79.9 ± 14.8	90.7 ± 16.1	78.4 ± 14.0*
Systolic blood pressure (mmHg)	136 ± 20	144 ± 22	135 ± 19*
Diastolic blood pressure (mmHg)	81 ± 10	80 ± 10	82 ± 10

Table 2—

Predictive performance of the CG and the MDRD formulae

iGFR [median (interquartile range)]	All subjects (n = 292)			Group 1 (iGFR <90; n = 37)
iGFR [median (interquartile range)]		114.9 (22.4)			83.8 (4.3); 84 (81–88)		119.4 (20.3); 115 (103–133)
Formula	CG	MDRD	CG	MDRD	CG	MDRD
eGFR [median (interquartile range)]	101.1 (26.8)	89.9 (19.0)	78.0 (16.5); 76 (69–88.5)	73.7 (12.0); 73 (64–82)	104.4 (26.3); 100 (87–120)	92.3 (18.7); 89 (78–103)
Bias	−13.8 (−16.1 to −11.6)	−25.0 (−26.9 to −23.1)	−5.8 (−11.1 to −0.6)	−10.7 (−14.4 to −7.0)	−15.0 (−17.4 to −12.5)	−27.1 (−29.1 to −25.1)
Precision	19.5	16.6	15.7	11.2	19.7	16.2
95% limits of agreement	(−52.8 to 25.2)	(−58.2 to 8.2)	(−37.2 to 25.6)	(−33.1 to 11.7)	(−54.4 to 24.4)	(−59.5 to 5.3)
Accuracy 10%	29% (24–35)	15% (11–19)	32% (19–50)	27% (14–44)	29% (23–35)	13% (9–18)
Accuracy 30%	86% (81–89)	79% (74–83)	86% (17–95)	95% (80–99)	85% (80–89)	76% (71–81)
R²	0.490	0.476	0.093*	0.119	0.450	0.429
Gradient	0.59 (0.52–0.65)	0.81 (0.71–0.91)	0.08 (−0.01 to 0.17)	0.13 (0.01–0.24)	0.52 (0.45–0.59)	0.71 (0.61–0.81)
Intercept	55.7 (48.5–63.0)	41.9 (32.9–51.0)	77.6 (70.8–84.4)	74.7 (66.1–83.3)	65.6 (57.9–73.2)	53.8 (44.2–63.3)

Data are means ± SD (95% CI), unless otherwise indicated. All R values were positive and, with one exception
*
↵* , significantly different from zero.

Table 3—

U.K. CKD staging of subjects in groups 1 and 2