Umbilical vein plasma concentrations of asymmetrical dimethylarginine are increased in male but not female neonates delivered preterm: a pilot study.
BACKGROUND
Infants born term have substantially elevated plasma concentrations of the endogenous nitric oxide synthase antagonist asymmetrical dimethylarginine (ADMA) that normalize with growth. The plasma levels of ADMA in preterm newborns are unknown.


METHODS
Plasma concentrations of ADMA, symmetrical dimethylarginine (SDMA) and L-arginine were analyzed from venous umbilical cord blood samples of 19 preterm and 21 term infants by high performance liquid chromatography.


RESULTS
Male preterm newborns (n=11) had higher ADMA (median [95% confidence interval (CI)]: 1.90 [1.73-2.10] micromol/l) than females born preterm (n=8; 1.57 [1.24-1.69] micromol/l; p<0.005). In term born males (n=10) and females (n=11) ADMA was significantly lower than in preterm male infants (all p<0.005), and without sex differences. SDMA and L-arginine concentrations were comparable between all groups. ADMA correlated inversely with body weight in male preterm newborns (r=-0.67; p<0.03).


CONCLUSIONS
Male neonates delivered preterm have significantly higher umbilical cord venous plasma concentrations of ADMA compared to female neonates and infants born term. The sex difference and the time course of elevated ADMA may play a role in development and warrant further investigation.
Mittermayer
Friedrich
F
Department of Clinical Pharmacology, Medical University Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
Prusa
Andrea-Romana
AR
Pollak
Arnold
A
Wolzt
Michael
M
D001120:Arginine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000502:physiology; D001775:Blood Circulation / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D008297:Male; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010865:Pilot Projects; D047928:Premature Birth / Q000097:blood*; D012727:Sex Characteristics; D013997:Time Factors
C487735:dimethylarginine; C018524:N,N-dimethylarginine; D001120:Arginine; D019001:Nitric Oxide Synthase