SERUM CREATININE IS A POOR MARKER OF GLOMERULAR-FILTRATION RATE IN PATIENTS WITH SPINA-BIFIDA

Serum creatinine is used to estimate the glomerular filtration rate (G FR). The serum creatinine, however, may not accurately reflect the GFR in spina bifida patients, who often have decreased overall muscle mas s resulting from spinal cord abnormalities. The relationship between t he serum creatinine and GFR (obtained by [I-125]iothalamate clearance) was examined in a population of spins bifida patients. Age-matched pa tients without spina bifida were used as controls. Results demonstrate that, for serum creatinines above 0.5 mg/dL, serum creatinine is a ve ry poor predictor of GFR. Two patients with serum creatinines of 2.2 m g/dL are near end-stage renal disease with GFRs of 12.5 and 13 mL/minu te per 1.73m(2) and two patients were initiated on dialysis at the con clusion of tile study. It is concluded that obtaining a GFR hom a clea rance study and not serum creatinine is the only reliable method to as sess renal function in spina bifida. patients once the serum creatinin e is greater than 0.5 mg/dL.