The plasma angiotensin II level increases in very low-birth weight infants with neonatal chronic lung disease

BackgroundAngiotensin II (AII) has been reported to play an important role in organ fibrosis, and a local renin–angiotensin-system (RAS) has been demonstrated in the lungs. However, the relationship of the RAS to chronic lung disease of the newborn (CLD) remains obscure.ObjectiveTo investigate the plasma AII levels throughout the neonatal period in very low-birth weight (VLBW) infants and examine the possible factors that might affect the AII levels.Study designThe study includes 20 VLBW infants. Blood samples were collected on days 0, 7, 21 and 35 and plasma AII levels were assayed using an enzyme immunoassay. The data were analyzed by a multiple linear regression analysis with the plasma AII level as the dependent variable and significant factors determined based on a univariate analysis as independent variables.ResultsThe geometric mean of the plasma AII concentrations on days 0, 7, 21 and 35 was 51 pg/mL, 86 pg/mL, 132 pg/mL, and 50 pg/mL, respectively. On day 21, only CLD (p < 0.01) had a highly significant association with the plasma AII level. On day 35, birth weight (p < 0.05) and CLD (p < 0.01) had a highly significant association with the plasma AII level. This analysis confirmed CLD to be the most significant factor associated with plasma AII level on days 21 and 35.ConclusionThese findings suggest that higher levels of plasma AII in VLBW infants appear to be related to the development of CLD.