COMPARISON OF URINARY AND PLASMA MALONDIALDEHYDE IN PRETERM INFANTS

The measurement of malondialdehyde (MDA) in biological fluids remains a popular method for the quantification of free radical damage to lipi ds in vivo. Several diseases of prematurity an thought to be related t o oxidative injury and previous studies have found elevated MDA in pla sma and urine in preterm infants. Our aim was to investigate the relat ionship between plasma and urinary MDA levels in preterm infants durin g the first week of life using a high-performance liquid chromatograph y (HPLC) based, thiobarbituric acid (TEA) assay with paired plasma and urine samples. We obtained 50 paired samples, and were unable to demo nstrate a relationship between the two parameters after the first day of life. In 18 cases a further urine sample was collected 24 h later. There was a positive correlation (r = 0.54, P = 0.02) between plasma M DA and urinary MDA 24 h later. The finding that plasma changes in MDA are reflected in urine 24 h later validates the use of urinary MDA as a marker of whole body lipid peroxidation in populations without renal disease. (C) 1997 Elsevier Science B.V.