IOHEXOL CLEARANCE FOR ASSESSMENT OF GLOMERULAR-FILTRATION RATE IN DIABETIC PREGNANCY

Background: Plasma clearance of iohexol (Omnipaque(R)) is well suited for determination of glomerular filtration rate (GFR) during pregnancy . Objective: To settle guidelines for the use of iohexol clearance in diabetic pregnancy. Study design: Prospective comparative. Material an d Methods: Iohexol (5 ml) was injected intravenously and plasma concen trations determined by high pressure liquid chromatography after 180-2 40 min in 44 diabetic pregnant women. Results: Iohexol clearance was n ormal in most cases of nephropathy or albuminuria. Iohexol clearance c orrelated negatively with blood pressure, S-Urate, and S-Creatinine. W hen S-Urate was <232 mu mol/l or S-Creatinine <70 mu mol/l; iohexol cl earance was always normal (sensitivity = 1.0). When, in combination, S -Urate was >345 mu mol/l and S-Creatinine >70 mu mol/l, iohexol cleara nce was always subnormal (sensitivity = specificity = Kappa index = 1. 0). Conclusions: In diabetic pregnancy, nephropathy or albuminuria can not solely be used for selection of candidates for iohexol clearance d etermination. A S-Urate <230 mu mol/l (3.9 mg/dl) or S-Creatinine <70 mu mol/l (0.92 mg/dl) was reassuring for a normal GFR. We suggest iohe xol clearance determinations in diabetic pregnancies when S-Urate is > 350 mu mol/l (5.9 mg/dl) and/or S-Creatinine >70 mu mol/L.