Table 2.

Mean estimated glomerular filtration rate (eGFR) and prevalence of stage 3 or 4 chronic kidney disease (CKD) calculated using the Modification of Diet in Renal Disease (MDRD) study equation and the cystatin C age, sex, race equation by body mass index

	Body mass index category (range, kg/m2)
	Normal weight (18.5 - 24.9)	Overweight (25.0 – 29.9)	Obesity (≥30.0)	P-Trend
Mean (SE) eGFR, ml/min/1.73m2
eGFRCysC,age,sex,race *	96.5 (1.0)	88.8 (0.9)	84.1 (1.3)
eGFRMDRD**	95.2 (0.9)	90.7 (0.9)	89.5 (1.1)
Difference
eGFRCysC,age,sex,race estimate minus eGFRMDRD estimate	1.4 (1.0)	−1.9 (0.9)	−5.4 (1.0)	0.0009
Stage 3 or 4 CKD prevalence † , % (SE)
eGFRCysC,age,sex,race	6.5 (0.7)	9.5 (0.8)	13.8 (1.5)
eGFRMDRD	4.2 (0.3)	6.5 (0.5)	7.4 (0.7)
Difference
eGFRCysC,age,sex,race estimate minus eGFRMDRD estimate	2.3 (0.4)	3.0 (0.7)	6.4 (1.2)	0.005

SE – standard error

^*eGFR_{CysC,age,sex,race} was derived from an equation including cystatin C, age, sex, race

^**eGFR_{MDRD was} derived from an equation including creatinine, age, sex, race

^†Percent prevalence of stage 3 or 4 CKD was defined by either eGFR_{CysC,age,sex,race} or eGFR_MDRD