Comparison of Different Glomerular Filtration Methods in the Elderly: Which Formula Provides Better Estimates?

Figures & data

Table 1. Demographic characteristics of study population.

Number	76
Age (years) (mean ± SD)	72.8 ± 5.3
Gender (male/female)	21/55
BMI (mean ± SD) (kg/m^2)	28.9 ± 5.5
Diabetes mellitus (n) (%)	32 (42.1)
Hypertension (n) (%)	59 (77.6)
Chronic renal disease (n) (%)	19 (25)
Congestive heart failure (n) (%)	14 (18.4)
Serum Alb (mean ± SD) (g/dL)	3.9 ± 0.4
Scr (mean ± SD) (mg/dL)	1.2 ± 0.6
Ucr (mean ± SD)(mg/dL)	779.4 ± 266.7
BUN (mean ± SD) (mg/dL)	48.3 ± 27.9

Note: BMI, body mass index; Alb, albumin; Scr, serum creatinine; Ucr, urine creatinine; BUN, blood urea nitrogen.

Table 2. GFR values calculated by using different methods.

	GFR (mean ± SD) (min–max) (n = 76)
^99mTc-DTPA	54.3 ± 19.9(8.1–99.1)
MDRD1	60.9 ± 22.1(10.9–124.0)
MDRD2	54.4 ± 20.1(11.0–120.0)
CGF	57.9 ± 22.4(13.7–121.6)
CrCl	58.0 ± 30.5(7.1–177.0)

Notes: GFR, glomerular filtration rate; ^99mTc-DTPA, technetium-99m diethylenetriaminepentaacetic acid; MDRD1, modification of diet in renal disease 1, MDRD2, modification of diet in renal disease 2; CGF, Cockroft–Gault formula; CrCl, creatinine clearance.

Table 3. Correlation analyses of the GFR methods (r values).

	DTPA	CrCl	MDRD1	MDRD2	CGF
DTPA	1.00	0.59	0.70	0.68	0.69
CrCl	0.59	1.00	0.73	0.78	0.71
MDRD1	0.70	0.73	1.00	0.97	0.85
MDRD2	0.68	0.78	0.97	1.00	0.85
CGF	0.69	0.71	0.85	0.85	1.00

Notes: GFR, glomerular filtration rate; DTPA, diethylenetriaminepentaacetic acid; CrCl, creatinine clearance; MDRD1, modification of diet in renal disease 1, MDRD2, modification of diet in renal disease 2; CGF, Cockroft–Gault formula.

p < 0.001.

Figure 1. Correlation between ^99mTc-DTPA and MDRD1.

Note: ^99mTc-DTPA, technetium-99m diethylenetriaminepentaacetic acid; MDRD1, modification of diet in renal disease 1.

Figure 2. Correlation between ^99mTc-DTPA and CGF.

Note: ^99mTc-DTPA, technetium-99m diethylenetriaminepentaacetic acid; CGF, Cockroft–Gault formula.

Figure 3. Correlation between ^99mTc-DTPA and CrCl.

Note: ^99mTc-DTPA, technetium-99m diethylenetriaminepentaacetic acid; CrCl, creatinine clearance.

Table 4. The correlation of the methods with ^99mTc-DTPA method based on subgroup characteristics.

	CrCl	MDRD1	MDRD2	CGF
Gender
Female (n = 55)	0.61**	0.70**	0.69**	0.68**
Male (n = 21)	0.50**	0.69**	0.65**	0.68**
Age
75 years or younger (n = 53)	0.54**	0.60**	0.57**	0.63**
75 years or older (n = 23)	0.42	0.71**	0.71**	0.59**
BMI
Below 30 kg/m^2 (n = 47)	0.54**	0.68**	0.66**	0.67**
Above 30 kg/m^2 (n = 29)	0.61**	0.71**	0.71**	0.69**
GFR
Below 60mL/min(n = 31)	0.60**	0.68**	0.67**	0.67**
Above 60 mL/min(n = 45)	0.53**	0.72**	0.68**	0.66**

Notes: ^99mTc-DTPA, technetium-99m diethylenetriaminepentaacetic acid; CrCl, creatinine clearance; MDRD1, modification of diet in renal disease 1; MDRD2, modification of diet in renal disease 2; CGF, Cockroft–Gault formula; BMI, body mass index; GFR, glomerular filtration rate.

^**p < 0.001; p < 0.05.