"CORRELATION BETTWEEN GLOMERULAR FILTRATION RATE (GFR) DERIVED FROM MDRD STUDY AND CREATININ CLEARANCE/BODY SURFACE (CRCLBS), GFR ESTIMATED (GFRE) AND KT/V WEEKLY IN PATIENTS ON PREDIALYSIS UNIT"

S. Cigarrán, G. Barril, R.Selgas

Unidad de Predialisis. Servicio de Nefrología. Hospital de la Princesa. Madrid. ESPAÑA
cigarran@ctv.es

GFRE is traditionally considered the best overall index to determine renal function in health and disease, being Cockcroft y Gault formula more widely used to predict it. Recently MDRD study developed a new formula, more accurate to evaluate GFR, based on age, sex, gender,height, serum creatinin, serum BUN and serum Albumin. The performance of GFR derived from MDRD in patients with CRI and compare with others indexes was the aim of the study.

86 pts were included in our PreESRD unit Mean age ( x¯)= 69.9 ± 12.08 yr, 42 M, 46 W, included with CrClbs <30 ml/min/1.73m2 . 26% were diabetic, 10.5% polycystic kidney disease, 24.4% nephroangiosclerosis, 39.1% other or unknown renal diseases. Parameters analyzed were , age, gender, weight, sex, height, serum Cr, serum Albumina , serum BUN, urine BUN, urine Cr , diuresis and proteinuria. Data were processed and stadistically analyzed with SPSS 10.0 software package. The relation of renal function measurements to other baseline characteristics was assessed by using contingency tables, t-tests, analysis of variance and linear regression, as appropiate. A P value less than 0.01 was considered statistically significant. We used stepwise multiple regression to determine a set of variables that predicted GFR.

Descriptive parameters of renal function were: (Table I)
 

N

Minimum

( ml/min/1.73)

Maximum

(ml/min/1.73)

Mean ± SD

( ml/min/1.73)

CrClbs

79

6.10

48.4

19.03 ± 7.66

GFR MDRD

82

6.5

45.4

15.8 ± 6.7

KT/V wk

72

0.8

6.1

2.27 ± .8

GFRE

79

4.8

35.3

13.1 ± 5.3

Linear regression results were (Table II)

GFR- MDRD relationship

Variable

Regression Coeff. (ß)

P

R2

CrClbs

0.83

<0.01

0.69

GFRE

0.79

<0.01

0.62

Kt/V wk

0.73

<0.01

0.54

Conclussions: GFR index derived from MDRD study has a strong positive correlation with others indexes used to predict renal function, specially with CrClbs. Also is specially usefull to predict the GFR in patients with disorders associated in which the 24 h- urine collection is not easy to perform.