Umbilical cord asymmetric dimethylarginine levels and ultrasound assessment of carotid arteries in neonates born small for gestational age

Background: To examine asymmetric dimethylarginine (ADMA) level as an endothelial function parameter in addition to ultrasonographic evaluation of carotid arteries in babies born small for gestational age (SGA). Methods: Twenty-six neonates born SGA and 34 appropriate for gestational age (AGA) controls were included in the study. The serum levels of ADMA were measured. Intima-media thickness (cIMT) and resistive index (cRI) of the both carotid arteries were determined by ultrasonography. Results: The mean ADMA level was higher in SGA neonates compared to AGAs (16 267.7 +/- 6050 versus 12 810.2 +/- 3302 ng/L; p = 0.01). The mean cIMT (0.34 +/- 0.02 versus 0.31 +/- 0.03 mm; p = 0.001) and cRI (0.66 +/- 0.07 versus 0.61 +/- 0.04, p = 0.003) were also higher in SGAs. Serum ADMA levels were positively correlated to the mean cIMT (r = 0.41, p = 0.001). Although there was a weak correlation between cIMT and mean cRI (r = 0.26, p = 0.04), no correlation was found between ADMA and mean cRI (r = 0.17, p = 0.18). Conclusions: Neonates born SGA have elevated cord blood ADMA level in addition to thicker IMT and higher RI of carotid arteries at birth. ADMA was correlated to cIMT, suggesting that higher ADMA levels might influence vascular health in later life in these neonates.